What is the scrotum for anyway? I think it should have a rib cage…. SuperFreakonomics is SuperFreakingWrong on global warming. A closer look at some of the guns science uses to mow down ignorance. Imagine having to get into a clam by rapping your knuckles on it. Hard right? Not for this shrimp. Can evolutionary theory help solve long-standing problems in economics? You might need a bio degree to read it. Watching bats fly in an x-ray is a science job I envy. Will we long for that mote of dust in the sunbeam? A homesick astronaut on Mars. XKCD with some more good skeptical advice on quantum mechanics.
Why does the shadow in this unedited image cast a future action? Cool optics on display. Possible spoilers but fun: How many people would a Kaiju need to eat everyday? How we think we would react to aliens tells us a lot about ourselves. Blast through Blade Runner in 60 seconds with stick figures. Unless you are The Flash. What is weight? Just some Flickr photos from an astronaut showing the toolbox on the ISS. I wish I could have a dog made out of circuit boards …. Any of these artsy science prints would be great for the inquisitive kid.
I linked to a cool shot of a photographer with burning shoes on a lava flow. In case you had a trade dispute with the Klingons: A massive map of Star Trek space. Our own Moon can look bizarre if you simply go around the back. The tentacles of youth. Atomic explosions have an odd beauty to them. An ash and lightning GIF you could watch all day. Holy wow. Every time I stumble on these 2D yet 3D drawings I am blown away.
Elastic collisions with volleyballs and glass are saweet. Like a glass cannon. You can really do that, but with H2O2. Because of this prettiness. Painting optical illusions onto people is visually pretty tiring. Perpetual snake motion machine is a high thread count bed sheet. With enough pictures of the moon landing, you can make it look 3D. GIF of a cicada molting is a metaphor for the coming of age film , maybe. Sometimes the social media focus seems a bit trivial. When will we have the first leaf-cutter ant superPAC?
A bunch of jacketed hippies have a drum circle with exposed ice. When Penn and Teller created the worst videogame ever. This is a science and pop culture blog where I try to let geekery run free. You awesome readers have proved to me time and time again that no matter how nerdy we want to get, someone will love us for it. Due to some unforeseen consequences bonus points for HL2 reference , I need to change the name of this blog.
Actually, I want you to rename it. You live in the past. For every possible combination of sensory input you can have, there is some appreciable time between signal and interpretation. Light hits your eye or a sound hits your ear and milliseconds later you actually perceive light or sound. Right now you are looking at this screen as it was a few milliseconds in the past. Reality is on a delay. For you, nothing is now. Realizing this fact is unsettling.
If we can only react to the past, how do we manage to navigate the present? The Flash is the fastest man, biped, anything. He can sprint at the speed of light. When he does, Einstein rests happily in his grave. The Flash tests and proves relativity every time he decides to burn latex. No matter what speed the red blur appears to observers, time effectively stands still for the crimson superhero.
But such power poses a problem. When you move that fast, you see bunch light together and change as you move—like how moving towards or away from a police car can make it sound louder or softer. The world would turn blue as you rush towards it. All light would appear to be at a higher frequency—a blue shift. The same effect is why hyper-speed in Star Wars actually a looks more like a blur than streaking lights and why galaxies moving away from us appear redder than they otherwise should. Of course, The Flash has a way around this—he lives closer to the present than any human.
He can process information and even think at the speed of light. The numeric comparisons are amazing, but this superhuman perception is almost transcendent. When you can process visual information that fast, the world would be crystal clear at any speed. Electrical signals travel and neurons fire in The Flash instantaneously.
He could pick out any individual frame from any movie maybe that single frame of porn from Fight Club. By contrast, our processing power is far less extraordinary. It is so underpowered that it made life difficult for early television engineers. Neuroscientist David Eagleman explains that engineers were worried about keeping audio and visual signals perfectly synchronized in the first broadcasts until they realized that they had a grace period of around milliseconds. Any two signals played closer together than this the brain would consider simultaneous and sync-up—a correction for slow perception.
Two signals played out of step beyond milliseconds made a broadcast look like a badly dubbed kung-fu movie. He has the latest episode of The Big Bang Theory rendered unwatchable by our regularly paced brains. Every TV show, movie, and videogame would look like a series of still frames—the frame rates would have to be astronomical to keep us visually entertained.
More consequentially, we could discover so much more than our brains can currently detect. There is a superfluity of science enveloped in the ticking seconds that we cannot perceive. You could stop to draw all the intricacies of a fluttering hummingbird wing in complete detail…in between beats.
The incredible physics hidden in tried and true chemistry experiments would leap out at us like barking dogs. Light speed perception would be a revolution on par with discovering the rest of the electromagnetic spectrum beyond visible light. Or you could spend your time racing Superman to see who is faster.
In between mining Vespene gas and constructing additional pylons, gamers have been unknowingly learning about how cancer works, and maybe how to beat it. Amid the frantic clicking and hot-keying that goes on in homes and internet cafes around the world, players of the immensely popular computer game StarCraft have been unknowingly gaining a working knowledge of cancer.
But the insight into the illness depends on which of the three races in the game you play. The future-minded Terran speak to dreams of human expansion in space. The telepathic Protoss keep spirituality in a galaxy dominated by science. In form, function, and strategy, the Zerg of StarCraft were designed to overwhelm opponents with numbers and genetic versatility. In the canon, the Zerg sweep through the galaxy to assimilate the genetic material of the strongest species. They artificially select themselves to succeed, as we do with dogs or cabbage. Inexperienced players can be swarmed within five minutes of starting a multiplayer match.
Like locusts, the Zerg move and act like insects of the Starship Troopers variety, and even bear striking resemblances to real world insect biology. A real and much more frightening swarm is cancer. A simple mistake in a cell can cause it to continue dividing instead of stopping or killing itself. One cell becomes two, two become four, four eventually become a tumor. Survival rates for different cancers vary from decent to terminal, but the chances of getting cancer are strikingly high. The chance of a US man or woman being diagnosed with some form of cancer is around 40 percent.
Cancer is so dangerous and difficult to treat because of the similarities the disease shares with the Zerg. As the cell uncontrollably divides, each successive division brings with it a chance for the new cancer cell to contain a mutation—DNA replication is never perfect. Most of the mutations will do nothing, but given how many cells are dividing—billions upon billions—mutations can spring up that give the cancer a selective advantage.
Maybe the mutation accelerates cell division. Maybe it redirects more blood flow to the growing mass of cells parasitically throbbing in your body. And maybe the mutation even helps the new cells evade the immune system. Cancer is real-time evolution, and your body is the selective pressure. The Zerg function in much the same way. Through rampant expansion, they are able to search out beneficial genetic material from the hardiest species, and intentionally put themselves in hostile environments to force their own, pressured evolution.
Only the strong survive in StarCraft , and the Zerg are a galactic cancer. The rapid evolution of a cancer is at the heart of why it is so hard to treat. Surgery is sometimes possible, but even a few cells left over can fuel the swarm again. Similarly, a solitary Zerg drone can become a whole hive if left unchecked. The best StarCraft players fight the Zerg like surgeons: If you see a tumor, you have to get it all to survive. But like how a cancer can thrive under the selective pressure of our bodies, treatments to get rid of it are even more pressures to evolve.
Chemotherapy fails , for example, because by the time the cancer is treated a number of the cancer cells could have a mutation that gives them resistance to it. The chemo will hopefully wipe out everything else, but those resistant remain to divide and conquer. Evolution is ultimately why cancer is so deadly. Take two biopsies from different sides of a tumor and they can be genetically very different, making it that much harder to fight. Variation is the toolbox of evolution, and this variation gives cancer strength.
Carl Zimmer in the New York Times recently reported on a clever way to possibly combat the mutations that can give cancer its deadly power. Treatments fail when a cancer has evolved to the point of resistance, but the more treatments that are provided simultaneously, the less likely a cancer cell is to have resistance to them.
Space Is an Ocean
The likelihood that a cancer cell has the mutation to resist two treatments is significantly less likely than resisting one treatment alone. StarCraft strategy already mimics a simultaneous assault on cancer. To win, you have to apply pressure quickly, consistently, and from all possible angles. One Terran battlecruiser with a Yamato Cannon is unlikely to stop the Zerg rush; throw in a simultaneous nuclear strike just to be safe science has shown that the Terran would be the galactic victors , after all.
To spread, the Zerg actually put down tumors ; their wide genetic variation also makes them deadly; and because the Zerg have DNA like the rest of us, they are also vulnerable to concentrated blasts of radiation like cancer is the same kind of thing that killed Kirk. Millions of players have been tirelessly clicking as analog oncologists wiping out a rapidly evolving foe, unknowingly discovering how real cancer works and possibly how to fight it. Science can creep up on you like that. Really weird to see something un-launch itself: This SpaceX rocket test video is ridiculously impressive.
What do we really know about how games affect us? So far so good for a new set of sweeping US classroom science standards. You ever read writing so good you are jealous of it? Homeopathy smacked down for misleading claims about what its placebo can treat. Decision here. When magic and empiricism meet in Uganda children get their teeth removed with a sharpened bicycle spoke.
Or do they just age realllly slowly? How many bouncy balls would it take to kill someone? Shatner is pissed. How nuclear fallout from the cold war can help us track and stop ivory poachers. How might NSA spying affect the clinically paranoid? Or, kill one if you see one. I learned! What the Fifth Element can teach you about design principles. Here, the immediate concerns are short-term survival and long-term health in fairly confined environments where one cannot simply 'open the window' for fresh air.
As such, one of the main concerns is air monitoring and the main sources of contamination are CO 2 and other constituents of human exhaled breath. Certainly, other air constituents are also important; for example, the closed environment of a submarine or the ISS can build up contaminants from consumer products, cooking, refrigeration, accidental fires, propulsion and atmosphere maintenance.
However, the most immediate concern is sustaining human metabolism: removing exhaled CO 2 and replacing metabolized O 2. Paint-Stirrer Submarine. In this article, the authors discuss a unique and challenging laboratory exercise called, the paint-stir-stick submarine , that keeps the students enthralled. The paint-stir-stick submarine fits beautifully with the National Science Education Standards Physical Science Content Standard B, and with the California state science standards for physical….
Litchford, Ron J. A fundamental obstacle to routine space access is the specific energy limitations associated with chemical fuels. In the case of vertical take-off, the high thrust needed for vertical liftoff and acceleration to orbit translates into power levels in the 10 GW range. Furthermore, useful payload mass fractions are possible only if the exhaust particle energy i.
The electronic binding energy released by the best chemical reactions e. As an added challenge, the envisioned hypothetical RLV reusable launch vehicle should accomplish these amazing performance feats while providing relatively low acceleration levels to orbit g maximum. From such fundamental considerations, it is painfully obvious that planned and current RLV solutions based on chemical fuels alone represent only a temporary solution and can only result in minor gains, at best.
What is truly needed is a revolutionary approach that will dramatically reduce the amount of fuel and size of the launch vehicle. This implies the need for new compact high-power energy sources as well as advanced accelerator technologies for increasing engine exhaust velocity. Electromagnetic acceleration techniques are of immense interest since they can be used to circumvent the thermal limits associated with conventional propulsion systems.
The purpose of the experiment is to demonstrate. Making a Submarine. Describes Archimedes principle and why a ship sinks when it gets a hole in it. Suggests an activity for teaching the concept of density and water displacement through the construction of a simple submarine. Includes materials and procedures for this activity. Arctic Submarine Slope Stability. Submarine landsliding represents aside submarine earthquakes major natural hazard to coastal and sea-floor infrastructure as well as to coastal communities due to their ability to generate large-scale tsunamis with their socio-economic consequences.
The investigation of submarine landslides, their conditions and trigger mechanisms, recurrence rates and potential impact remains an important task for the evaluation of risks in coastal management and offshore industrial activities. In the light of a changing globe with warming oceans and rising sea-level accompanied by increasing human population along coasts and enhanced near- and offshore activities, slope stability issues gain more importance than ever before. The Arctic exhibits the most rapid and drastic changes and is predicted to change even faster.
Aside rising air temperatures, enhanced inflow of less cooled Atlantic water into the Arctic Ocean reduces sea-ice cover and warms the surroundings. Slope stability is challenged considering large areas of permafrost and hydrates. The HYM exhibits the highest headwalls that have been found on siliciclastic margins. With more than Geometry and age put this slide in a special position in discussing submarine slope stability on glaciated continental margins.
The HYM occurred 30 ka ago, when the global sea-level dropped by app. It probably caused a tsunami with circum-Arctic impact and wave heights exceeding meters. The HYM affected the slope stability field in its neighbourhood by removal of support. Post-megaslide slope instability as expressed in creeping and smaller-scaled slides are. Submarine Construction Unterseebootsbau.
Extreme Tissue Engineering - Extreme Tissue Engineering - Wiley Online Library
Ultrasonic propulsion. In this investigation, a propulsion system is introduced for propelling and guiding an object through a fluid. Thrust for forward motion and for turning is produced by acoustic waves generated by piezoelectric ultrasonic transducers. The principle of operation of the transducers is described, and methods are presented for the design of the entire system, including the transducers, signal generator, guidance and control system, and the power source.
A wirelessly controlled proof-of-concept device was constructed. This device demonstrates the operation and practicality of the propulsion and guidance systems and illustrates that they may be employed in situations where the use of conventional propulsive devices such as propellers or jets is unfeasible. Improved trapped fields of 17 T at 29 K and Such high field strengths give the possibility for producing superconductor permanent magnets SCPM for plasma-related space propulsion applications, such as the anti-matter trap, magnetohydrodynamic MHD propulsion and electrical power generation, and others that are under development or being studied.
The SCPM could be beneficial in reducing the weight-to-power ratio for the associated delivery and containment systems needed for plasma interactions that are inherently imbedded in many of these propulsion systems. In this paper, a review of the superconductor literature is presented, followed by uses of the SCPM in high-performance space propulsion applications. Disk MHD generator study. Directly-fired, separately-fired, and oxygen-augmented MHD power plants incorporating a disk geometry for the MHD generator were studied.
The base parameters defined for four near-optimum-performance MHD steam power systems of various types are presented. The finally selected systems consisted of 1 two directly fired cases, one at K F preheat and the other at K F preheat, 2 a separately-fired case where the air is preheated to the same level as the higher temperature directly-fired cases, and 3 an oxygen augmented case with the same generator inlet temperature of F as the high temperature directly-fired and separately-fired cases.
Supersonic Mach numbers at the generator inlet, gas inlet swirl, and constant Hall field operation were specified based on disk generator optimization. System pressures were based on optimization of MHD net power. Supercritical reheat stream plants were used in all cases. Open and closed cycle component costs are summarized and compared. MHD Generating system. According to the present invention, coal combustion gas is the primary working fluid and copper or a copper alloy is the electrodynamic fluid in the MHD generator, thereby eliminating the heat exchangers between the combustor and the liquid-metal MHD working fluids, allowing the use of a conventional coalfired steam bottoming plant, and making the plant simpler, more efficient and cheaper.
In operation, the gas and liquid are combined in a mixer and the resulting two-phase mixture enters the MHD generator.
- Ultraman Mebius - Wikipedia.
- Memorial Day tribute – USS Iowa final voyage this weekend | Watts Up With That?.
- World War II Battleship on Battleship Engagements.
- The Overdose.
- The New Abs Diet: The 6-Week Plan to Flatten Your Stomach and Keep You Lean for Life (The Abs Diet)?
- Shooting Butterflies?
The MHD generator acts as a turbine and electric generator in one unit wherein the gas expands, drives the liquid across the magnetic field and thus generates electrical power. The gas and liquid are separated, and the available energy in the gas is recovered before the gas is exhausted to the atmosphere. Where the combustion gas contains sulfur, oxygen is bubbled through a side loop to remove sulfur therefrom as a concentrated stream of sulfur dioxide. The combustor is operated substoichiometrically to control the oxide level in the copper.
Status of Magnetohydrodynamic Augmented Propulsion Experiment. Over the past several years, efforts have been under way to design and develop an operationally flexible research facility for investigating the use of cross-field MHD accelerators as a potential thrust augmentation device for thermal propulsion systems, The baseline configuration for this high-power experimental facility utilizes a 1,5-MW, multi-gas arc-heater as a thermal driver for a 2-MW, MHD accelerator, which resides in a large-bore 2-tesla electromagnet.
A preliminary design study using NaK seeded nitrogen as the working fluid led to an externally diagonalized segmented MHD channel configuration based on an expendable beat-sink design concept. Submarine Landslides: A Multidisciplinary Crossroad. The study of submarine landslides has advanced considerably in the last decade. A multitude of geoscience disciplines, including marine, petroleum and planetary geology, as well as geohazard assessments, are concerned with the study of these units.
Oftentimes, researchers working in these fields disseminate their findings within their own communities and a multidisciplinary approach seems to lack. This presentation showcases several case studies in which a broader approach has increased our understanding of submarine landslides in a variety of geologic settings. Three-dimensional seismic data from several continental margins Trinidad, Brazil, Morocco, Canada, GOM , as well as data from outcrop localities are shown to explore geomorphological complexities associated with submarine landslides.
Discussion associated with the characterization and classification of submarine landslides is also part of this work. Topics that will be cover include: 1 how data from conventional oil and gas exploration activities can be used to increase our understanding of the dynamic behavior of submarine landslides, 2 analogies between terrestrial submarine landslides and potential Martian counterparts, 3 impact of submarine landslides in margin construction, as well as their economic significance and 4 the importance of quantifying the morphology of submarine landslides in a systematic fashion.
Submarine laser communications. Two approaches are under investigation - one in which the laser itself is space-based, and the other in which the laser is ground-based with its beam redirected to the earth's surface by an orbiting mirror. This paper discusses these two approaches, and presents a brief history of activities which led to the current studies. O'Connell, R. A MHD experiment is being constructed which will have the possibility of showing dynamo action: the self--generation of currents from fluid motion.
The design allows sufficient experimental flexibility and diagnostic access to study a variety of issues central to dynamo theory, including mean--field electrodynamics and saturation backreaction physics. Initially, helical flows required for dynamo action will be driven by propellers embedded in liquid sodium. The flow fields will first be measured using laser doppler velocimetry in a water experiment with an identical fluid Reynolds number. The magnetic field evolution will then be predicted using a MHD code, replacing the water with sodium; if growing magnetic fields are found, the experiment will be repeated with sodium.
Electromagnetic Propulsion. The design and development of an Electromagnetic Propulsion is discussed. Electric Propulsion. Next Generation Electric Propulsion NGEP technology development tasks are working towards advancing solar-powered electric propulsion systems and components to levels ready for transition to flight systems. The growing number of solar electric propulsion options provides reduced cost and flexibility to capture a wide range of Solar System exploration missions.
Benefits of electric propulsion systems over state-of-the-art chemical systems include increased launch windows, which reduce mission risk; increased deliverable payload mass for more science; and a reduction in launch vehicle size-- all of which increase the opportunities for New Frontiers and Discovery class missions.
The Dawn Discovery mission makes use of electric propulsion for sequential rendezvous with two large asteroids Vesta then Ceres , something not possible using chemical propulsion. NEXT components and thruster system under development have NSTAR heritage with significant increases in maximum power and Isp along with deep throttling capability to accommodate changes in input power over the mission trajectory. NEXT will produce engineering model system components that will be validated through qualification-level and integrated system testing and ready for transition to flight system development.
CBIO addresses the need to further extend ion thruster lifetime by using low erosion carbon-based materials. In addition, JPL completed a hr. Protection of the motor from accidental seawater grounding or seawater Condition Al Sum W1-W7 The theoretical performance of a scramjet propulsion system incorporating an magneto-hydro-dynamic MHD energy bypass scheme is calculated.
The one-dimensional analysis developed earlier, in which the theoretical performance is calculated neglecting skin friction and using a sudden-freezing approximation for the nozzle flow, is modified to incorporate the method of Van Driest for turbulent skin friction and a finite-rate chemistry calculation in the nozzle. Unlike in the earlier design, in which four ramp compressions occurred in the pitch plane, in the present design the first two ramp compressions occur in the pitch plane and the next two compressions occur in the yaw plane.
The results for the simplified design of a spaceliner show that 1 the present design produces higher specific impulses than the earlier design, 2 skin friction substantially reduces thrust and specific impulse, and 3 the specific impulse of the MHD -bypass system is still better than the non- MHD system and typical rocket over a narrow region of flight speeds and design parameters. Results suggest that the energy management with MHD principles offers the possibility of improving the performance of the scramjet.
The technical issues needing further studies are identified. Cometary MHD and chemistry. An MHD and chemical comet-coma model was developed, applying the computer program of Huebner for the detailed chemical evolution of a spherically expanding coma and the program of Schmidt and Wegman and Wegman for the MHD flow of plasma and magnetic field in a comet to the Giotto-mission data on the ion abundances measured by the HIS ion mass spectrometer.
The physics and chemistry of the coma are modeled in great detail, including photoprocesses, gas-phase chemical kinetics, energy balance with a separate electron temperature, multifluid hydrodynamics with a transition to free molecular flow, fast-streaming atomic and molecular hydrogen, counter and cross streaming of the ionized species relative to the neutral species in the coma-solar wind interaction region with momentum exchange by elastic collisions, mass-loading through ion pick-up, and Lorentz forces of the advected magnetic field.
The results, both inside and outside of the contact surface, are discussed and compared with the relevant HIS ion mass spectra. Propulsion controls. Increased system requirements and functional integration with the aircraft have placed an increased demand on control system capability and reliability. To provide these at an affordable cost and weight and because of the rapid advances in electronic technology, hydromechanical systems are being phased out in favor of digital electronic systems.
The transition is expected to be orderly from electronic trimming of hydromechanical controls to full authority digital electronic control. Future propulsion system controls will be highly reliable full authority digital electronic with selected component and circuit redundancy to provide the required safety and reliability. Redundancy may include a complete backup control of a different technology for single engine applications. The propulsion control will be required to communicate rapidly with the various flight and fire control avionics as part of an integrated control concept.
Propulsion Systems. Manual 91 - Vol. Astrium EADS. Sullivan, D. Chapter 3. Production of MHD fluid. A hot gaseous fluid of low ash content, suitable for use in open-cycle MHD magnetohydrodynamic power generation, is produced by means of a three-stage process comprising 1 partial combustion of a fossil fuel to produce a hot gaseous product comprising CO.
New Generation Strategic Submarine Study. Ship Propulsion System. Ship Propulsion MHD program plan, FY The current magnetohydrodynamic MHD program being implemented is a result of a consensus established in public meetings held by the Department of Energy in This plan focused on demonstrating the proof-of-concept POC of coal-fired MHD electric power plants by the early s.
MHD test data indicate that while there are no fundamental technical barriers impeding the development of MHD power plants, technical risk remains. To reduce the technical risk three key subsystems topping cycle, bottoming cycle, and seed regeneration are being assembled and tested separately.
The program does not require fabrication of a complete superconducting magnet, but rather the development and testing of superconductor cables. The topping cycle system test objectives can be achieved using a conventional iron core magnet system already in place at a DOE facility. Systems engineering-derived requirements and analytical modeling to support scale-up and component design guide the program. In response to environmental, economic, engineering, and utility acceptance requirements, design choices and operating modes are tested and refined to provide technical specifications for meeting commercial criteria.
These engineering activities are supported by comprehensive and continuing systems analyses to establish realistic technical requirements and cost data. Essential elements of the current program are to: develop technical and environmental data for the integrated MHD topping cycle and bottoming cycle systems through POC testing and hours, respectively ; design, construct, and operate a POC seed regeneration system capable of processing spent seed materials from the MHD bottoming cycle; prepare conceptual designs for a site specific MHD retrofit plant; and continue supporting research necessary for system testing.
Propulsion Systems Panel deliberations. Bianca, Carmelo J. The Propulsion Systems Panel was established because of the specialized nature of many of the materials and structures technology issues related to propulsion systems. Submarine geothermal resources. This amount is roughly equivalent to man's present gross energy consumption rate.
A sub-seafloor geothermal reservoir, to be exploitable under future economic conditions, will have to be hot, porous, permeable, large, shallow, and near an energy-deficient, populated land mass. Furthermore, the energy must be recoverable using technology achievable at a competitive cost and numerous environmental, legal and institutional problems will have to be overcome. The highest-temperature reservoirs should be found adjacent to the zones of the seafloor extension or volcanism that are subject to high sedimentation rates.
The relatively impermeable sediments reduce hydrothermal-discharge flow rates, forcing the heat to be either conducted away or released by high-temperature fluids, both of which lead to reservoir temperatures that can exceed ?? There is evidence that the oceanic crust is quite permeable and porous and that it was amenable to deep km penetration by seawater at least some time in the early stages of its evolution.
Most of the heat escapes far from land, but there are notable exceptions. For example, in parts of the Gulf of California, thermal gradients in the bottom sediments exceed 1?? In the coastal areas of the Gulf of California, where electricity and fresh water are at a premium, this potential resource lies in shallow water Electric vehicle propulsion alternatives.
Propulsion technology development for electric vehicles is summarized. Analytical studies, technology evaluation, and the development of technology for motors, controllers, transmissions, and complete propulsion systems are included. A nuclear detonation at altitudes several hundred kilometers above the earth will severely distort the earth's magnetic field and result in a strong magnetohydrodynamic electromagnetic pulse MHD -EMP. The geomagnetic disturbance interacts with the soil to induce current and horizontal electric gradients.
MHD -EMP is similar to solar geomagnetic storms in it's global and low frequency less than 1 Hz nature except that E3 can be much more intense with a far shorter duration. When the MHD -EMP gradients are integrated over great distances by power lines, communication cables, or other long conductors, the induced voltages are significant.
The horizontal gradients in the soil are too small to induce major responses by local interactions with facilities. If this current flows through transformer windings, it can saturate the magnetic circuit and cause 60 Hz harmonic production. To mitigate the effects of MHD -EMP on a facility, long conductors must be isolated from the building and the commercial power harmonics and voltage swings must be addressed.
The transfer switch would be expected to respond to the voltage fluctuations as long as the harmonics have not interfered with the switch control circuitry. The major sources of MHD -EMP induced currents are the commercial power lines and neutral; neutral current indirect coupling to the facility power or ground system via the metal fence, powered gate, parking lights, etc; metal water pipes; phone lines; and other long conductors that enter or come near the facility. The major source of harmonics is the commercial power system.
Megawatt Electromagnetic Plasma Propulsion. The NASA Glenn Research Center program in megawatt level electric propulsion is centered on electromagnetic acceleration of quasi-neutral plasmas. In the case of the MPD thruster, a multifaceted approach of experiments, computational modeling, and systems-level models of self field MPD thrusters is underway.
The MPD thruster experimental research consists of a MWe, 2 ms pulse-forming-network, a vacuum chamber with two 32 diffusion pumps, and voltage, current, mass flow rate, and thrust stand diagnostics. Current focus is on obtaining repeatable thrust measurements of a Princeton Benchmark type self field thruster operating at 0. Operation with hydrogen is the ultimate goal to realize the increased efficiency anticipated using the lighter gas. This design is awaiting testing in the experimental facility.
Although the calculated results have been found to be sensitive to the initial ionization assumptions, recent results have agreed well with experimental data. Finally, a systems level self-field MPD thruster model has been developed that allows for a mission planner or system designer to input Isp and power level into the model equations and obtain values for efficiency, mass flow rate, and input current and voltage. This model emphasizes algebraic simplicity to allow its incorporation into larger trajectory or system optimization codes.
The systems level approach will be extended to the pulsed inductive. Successful experiments on an external MHD Accelerator: wall confinement of the plasma, annihilation of the electrothermal instability by magnetic gradient inversion, creation of a stable spiral current pattern. MHD propulsion has been extensively studied since the fifties.
To shift from propulsion to an MHD Aerodyne, one only needs to accelerate the air externally, along its outer skin, using Lorentz forces. We present a set of successful experiments, obtained around a model, placed in low density air. We successfully dealt with various problems: wall confinement of two-temperature plasma obtained by inversion of the magnetic pressure gradient, annihilation of the Velikhov electrothermal instability by magnetic confinement of the streamers, establishment of a stable spiral distribution of the current, obtained by an original method.
Another direction of research is devoted to the study of an MHD -controlled inlet which, coupled with a turbofan engine and implying an MHD -bypass system, would extend the flight domain to hypersonic conditions. Research manager. Being the higher quantity and older generation submarine hull type, the Los Angeles class submarine. Solar Thermal Propulsion Concept.
Harnessing the Sun's energy through Solar Thermal Propulsion will propel vehicles through space by significantly reducing weight, complexity, and cost while boosting performance over current conventional upper stages. Another solar powered system, solar electric propulsion , demonstrates ion propulsion is suitable for long duration missions.
Pictured is an artist's concept of space flight using solar thermal propulsion. Over the past several years, NASA Marshall Space Flight Center has engaged in the design and development of an experimental research facility to investigate the use of diagonalized crossed-field magnetohydrodynamic MHD accelerators as a possible thrust augmentation device for thermal propulsion systems. In support of this effort, a three-dimensional numerical MHD model has been developed for the purpose of analyzing and optimizing accelerator performance and to aid in understanding critical underlying physical processes and nonideal effects.
This Technical Memorandum fully summarizes model development efforts and presents the results of pretest performance optimization analyses. These results indicate that the MHD accelerator should utilize a 45deg diagonalization angle with the applied current evenly distributed over the first five inlet electrode pairs. A self-field magnetoplasmadynamic MPD thruster is a low-thrust electric propulsion space-system that enables the usage of magnetohydrodynamic MHD principles for accelerating a plasma flow towards high speed exhaust velocities.
It can produce an high specific impulse, making it suitable for long duration interplanetary space missions. The numerical model is based on the macroscopic MHD equations for compressible and electrically resistive flow and is able to predict the two most important thrust mechanisms that are associated with this kind of propulsion system, namely the thermal thrust and the electromagnetic thrust. Moreover, due to the range of very high temperatures that could occur during the operation of the MPD, it also includes a real gas model for argon. Simulating a Submarine Hydrothermal Vent.
Space propulsion. Lewis Research Center is developing broad-based new technologies for space chemical engines to satisfy long-term needs of ETO launch vehicles and other vehicles operating in and beyond Earth orbit. This effort encompasses research related to design analysis and manufacturing processes needed to apply advanced materials to subcomponents, components, and subsystems of space-based systems and related ground-support equipment.
High-performance space-based chemical engines face a number of technical challenges. Tolerances on fillets are critical on large impellers. Advanced materials and fabricating techniques are needed to address these and other issues of interest. Turbopump bearings are needed which can provide reliable, long life operation at high speed and high load with low friction losses.
Hydrostatic bearings provide good performance, but transients during pump starts and stops may be an issue because no pressurized fluid is available unless a separate bearing pressurization system is included. Advanced materials are also needed to improve the lifetime, reliability and performance of other propulsion system elements such as seals and chambers.
The Submarine , Eventually there Then, because they had no way of rescuing those who had survived the. Magnetohydrodynamic MHD channel corner seal. A corner seal for an MHD duct includes a compressible portion which contacts the duct walls and an insulating portion which contacts the electrodes, sidewall bars and insulators.
The compressible portion may be a pneumatic or hydraulic gasket or an open-cell foam rubber. The insulating portion is segmented into a plurality of pieces of the same thickness as the electrodes, insulators and sidewall bars and aligned therewith, the pieces aligned with the insulator being of a different size from the pieces aligned with the electrodes and sidewall bars to create a stepped configuration along the corners of the MHD channel.
Magnetohydrodynamic Augmented Propulsion Experiment: I. Performance Analysis and Design. Litchford, R. The performance of conventional thermal propulsion systems is fundamentally constrained by the specific energy limitations associated with chemical fuels and the thermal limits of available materials.
Electromagnetic thrust augmentation represents one intriguing possibility for improving the fuel composition of thermal propulsion systems, thereby increasing overall specific energy characteristics; however, realization of such a system requires an extremely high-energy-density electrical power source as well as an efficient plasma acceleration device.
This Technical Publication describes the development of an experimental research facility for investigating the use of cross-field magnetohydrodynamic MHD accelerators as a possible thrust augmentation device for thermal propulsion systems. In this experiment,a 1. The heatsink MHD accelerator is configured as an externally diagonalized, segmented channel, which is inserted into a large-bore, 2-T electromagnet.
The performance analysis and engineering design of the flow path are described as well as the parameter measurements and flow diagnostics planned for the initial series of test runs. Ion propulsion. An ion engine is a plasma thruster which produces thrust by extracting ions from the plasma and accelerating them to high velocity with an electrostatic field. The ions are then neutralized and leave the engine as high velocity neutral particles. The advantages of ion engines are high specific impulse and efficiency and their ability to operate over a wide range of input powers.
In comparison with other electric thrusters, the ion engine has higher efficiency and specific impulse than thermal electric devices such as the arcjet, microwave, radiofrequency and laser heated thrusters and can operate at much lower current levels than the MPD thruster. However, the thrust level for an ion engine may be lower than a thermal electric thruster of the same operating power, consistent with its higher specific impulse, and therefore ion engines are best suited for missions which can tolerate longer duration propulsive phases.
The critical issue for the ion engine is lifetime, since the prospective missions may require operation for several thousands of hours. The critical components of the ion engine, with respect to engine lifetime, are the screen and accelerating grid structures. Typically, these are large metal screens that must support a large voltage difference and maintain a small gap between them.
Metallic whisker growth, distortion and vibration can lead to arcing, and over a long period of time ion sputtering will erode the grid structures and change their geometry. In order to study the effects of long time operation of the grid structure, we are developing computer codes based on the Particle-In-Cell PIC technique and Laser Induced Fluorescence LIF diagnostic techniques to study the physical processes which control the performance and lifetime of the grid structures.
Report provides status reporting on activities under order no. H for the period December 1 through December 31, Details the activities of the contract in the coordination of planned conduct of experiments at the MSFC Advanced Propulsion Laboratory in pulse detonation MHD power production and metals combustion. Beamed energy propulsion. Beamed energy concepts offer an alternative for an advanced propulsion system.
The use of a remote power source reduces the weight of the propulsion system in flight and this, combined with the high performance, provides significant payload gains. Within the context of this study's baseline scenario, two beamed energy propulsion concepts are potentially attractive: solar thermal propulsion and laser thermal propulsion. The conceived beamed energy propulsion devices generally provide low thrust tens of pounds to hundreds of pounds ; therefore, they are typically suggested for cargo transportation. For the baseline scenario, these propulsion system can provide propulsion between the following nodes: 1 low Earth orbit to geosynchronous Earth orbit; 2 low Earth orbit to low lunar orbit; 3 low lunar orbit to low Mars orbit--only solar thermal; and 4 lunar surface to low lunar orbit--only laser thermal.
OTV Propulsion Issues. The statistical technology needs of aero-assist maneuvering, propulsion , and usage of cryogenic fluids were presented. Industry panels discussed the servicing of reusable space based vehicles and propulsion -vehicle interation. Hybrid rocket propulsion. Topics addressed are: 1 comparison of the theoretical impulses; 2 comparison of the density-specific impulses; 3 general propulsion system features comparison; 4 hybrid systems, booster applications; and 5 hybrid systems, upper stage propulsion applications.
Sled tests focused on pelvis behavior and submarining can be found in the literature. However, they were performed either with rigid seats or with commercial seats. The objective of this study was to get reference tests to assess the submarining ability of dummies in more realistic conditions than on rigid seat, but still in a repeatable and reproducible setup. For this purpose, a semi-rigid seat was developed, which mimics the behavior of real seats, although it is made of rigid plates and springs that are easy to reproduce and simulate with an FE model.
In total, eight PMHS sled tests were performed on this semirigid seat to get data in two different configurations: first in a front seat configuration that was designed to prevent submarining , then in a rear seat configuration with adjusted spring stiffness to generate submarining. All subjects sustained extensive rib fractures from the shoulder belt loading.
No pelvis fractures and no submarining were observed in the front seat configuration, but two subjects sustained lumbar vertebrae fractures. In the rear seat configuration, all subjects sustained pelvic fractures and demonstrated submarining. Corridors were constructed for the external forces and the PMHS kinematics. They are provided in this paper as new reference tests to assess the biofidelity of human surrogates in different configurations that either result in submarining or do not.
In future, it is intended to analyze further seat and restraint system configurations to be able to define a submarining predictor. Gynecological and pregnancy related issues constitute the final area of review. Nuclear Submarines and Aircraft Carriers Radiation Nuclear submarines and aircraft carriers are powered by onboard nuclear reactors. Heat from the nuclear reaction makes the steam needed to power the submarine. When a nuclear vessel is taken out of service, its radioactive parts are disposed of and monitored.
Currents in monterey submarine canyon. Flow fields of mean, subtidal, and tidal frequencies between and m water depths in Monterey Submarine Canyon are examined using current measurements obtained in three yearlong field experiments. Spatial variations in flow fields are mainly controlled by the topography shape and width of the canyon. The day spring-neap cycle and a???
Neither of them seems directly correlated with the spring-neap cycle of the sea level. Submarine landslides: advances and challenges. Due to the recent development of well-integrated surveying techniques of the sea floor, significant improvements were achieved in mapping and describing the morphology and architecture of submarine mass movements. Except for the occurrence of turbidity currents, the aquatic environment marine and fresh water experiences the same type of mass failure as that found on land. Submarine mass movements, however, can have run-out distances in excess of km, so their impact on any offshore activity needs to be integrated over a wide area.
This great mobility of submarinemass movements is still not very well understood, particularly for cases like the far-reaching debris flows mapped on the Mississippi Fan and the large submarine rock avalanches found around many volcanic islands. A major challenge ahead is the integration of mass movement mechanics in an appropriate evaluation of the hazard so that proper risk assessment methodologies can be developed and implemented for various human activities offshore, including the development of natural resources and the establishment of reliable communication corridors.
Key words : submarine slides, hazards, risk assessment, morphology, mobility, tsunami. Le dveloppement rcent de techniques de levs hydrograhiques pour les fonds marins nous a permis d'atteindre une qualit ingale dans la cartographie et la description des glissements sous marins. Par contre, les glissements sous-marins peuvent atteindre des distances excdant km de telle sorte que leur impact sur les activits offshore doit tre pris en compte sur degrandes tendues. La grande mobilit des glissements sous-marins n'est pas encore bien comprise, comme pour le cas des coules dedbris cartographies sur le cne du Mississippi ainsi que pour les grandes avalanches rocheuses sous-marines retrouves au pourtour des les volcaniques.
Un dfi majeur. Incompressible magnetohydrodynamic MHD turbulence and magnetic dynamos, which occur in magnetofluids with large fluid and magnetic Reynolds numbers, will be discussed. When Reynolds numbers are large and energy decays slowly, the distribution of energy with respect to length scale becomes quasi-stationary and MHD turbulence can be described statistically. In the limit of infinite Reynolds numbers, viscosity and resistivity become zero and if these values are used in the MHD equations ab initio, a model system called ideal MHD turbulence results.
This model system is typically confined in simple geometries with some form of homogeneous boundary conditions, allowing for velocity and magnetic field to be represented by orthogonal function expansions. One advantage to this is that the coefficients of the expansions form a set of nonlinearly interacting variables whose behavior can be described by equilibrium statistical mechanics, i.
Another advantage is that truncated expansions provide a finite dynamical system whose time evolution can be numerically simulated to test the predictions of the associated statistical mechanics. If ensemble predictions are the same as time averages, then the system is said to be ergodic; if not, the system is nonergodic. Although it had been implicitly assumed in the early days of ideal MHD statistical theory development that these finite dynamical systems were ergodic, numerical simulations provided sufficient evidence that they were, in fact, nonergodic.
Specifically, while canonical ensemble theory predicted that expansion coefficients would be i zero-mean random variables with ii energy that decreased with length scale, it was found that although ii was correct, i was not and the expected ergodicity was broken. The exact cause of this broken ergodicity was explained, after much. Directions in propulsion control. Discussed here is research at NASA Lewis in the area of propulsion controls as driven by trends in advanced aircraft. The objective of the Lewis program is to develop the technology for advanced reliable propulsion control systems and to integrate the propulsion control with the flight control for optimal full-system control.
Solar Thermal Propulsion. Identification of propulsion systems. This paper presents a tutorial on the use of model identification techniques for the identification of propulsion system models. These models are important for control design, simulation, parameter estimation, and fault detection. Propulsion system identification is defined in the context of the classical description of identification as a four step process that is unique because of special considerations of data and error sources.
Propulsion system models are described along with the dependence of system operation on the environment. Propulsion system simulation approaches are discussed as well as approaches to propulsion system identification with examples for both air breathing and rocket systems. The engine is based on a rectangular cross-section tube coupled to a converging-diverging nozzle, which is in turn attached to a segmented Faraday channel. Rapid transition to detonation wave propagation was insured through the use of a short Schelkin spiral near the head of the engine.
The engine was first tested in a straight tube configuration without a nozzle, and the time resolved thrust was measured simultaneously with the head-end pressure. Similar measurements were made with the converging-diverging nozzle attached. The time correlation of the thrust and head-end pressure data was found to be excellent. The major purpose of the converging-diverging nozzle was to configure the engine for driving an MHD generator for the direct production of electrical power.
Additional tests were therefore necessary in which seed cesium-hydroxide dissolved in methanol was directly injected into the engine as a spray. The exhaust plume was then interrogated with a microwave interferometer in an attempt to characterize the plasma conditions, and emission spectroscopy measurements were also acquired.
Data reduction efforts indicate that the plasma exhaust is very highly ionized, although there is some uncertainty at this time as to the relative abundance of negative OH ions. The emission spectroscopy data provided some indication of the species in the exhaust as well as a measurement of temperature. A electrode-pair segmented Faraday channel and 0. The working principle comprises an MHD channel, surrounded by a magnet, filled with a molten, highly conductive metal into which gas is pumped. The heat of the metal expands the gas, forcing a flow through the magnetic field crossing the channel, thus creating an electrical current conducted by the metal.
The gas and metal are separated by a centrifugal device and both are redirected into the channel, forming thereby a double closed circuit when the heat of the molten metal is returned to the flow. Necessary characteristics for the gas such as a fairly low vaporization temperature and nonmiscibility with the metal, are outlined, and a space system using Li-Cs or Z-K as the heat carrier kept molten by a parabolic dish system is sketched.
Equations governing the fluid mechanics, thermodynamics, and the electrical generation are defined. The construction of a prototype MHD generator using a tin-water flow operating at C, a temperature suitable for coupling to solar heat sources, is outlined, noting expected efficiencies of percent. Nuclear energy as a source of power for space missions, represents an enabling technology for advanced and ambitious space applications.
Nuclear fuel in a gaseous or liquid form has been configured as a promising and practical candidate in this regard. The present study investigates and performs a feasibility analysis of an innovative concept for space power generation and propulsion. The reactor utilizes liquid uranium in droplet form as fuel and superheated metallic vapor as the working fluid. This ultrahigh temperature vapor core reactor brings forward varied and challenging technical issues, and it has been addressed to in this paper.
A parametric study of the conceived system has been performed in a qualitative and quantitative manner. Preliminary results show enough promise for further indepth analysis of this novel system. Rapporteur report: MHD electric power plants. Results of the initial parametric phase of the US effort on the study of potential early commercial MHD plants are reported and aspects of the smaller commercial prototype plant termed the Engineering Test Facility are discussed.
The alternative of using a disk geometry generator rather than a linear generator in baseload MHD plants is examined. Closed-cycle as well as open-cycle MHD plants are considered. Space Propulsion Technology Program Overview. The topics presented are covered in viewgraph form.frarongemeri.cf
Focused program elements are: 1 transportation systems, which include earth-to-orbit propulsion , commercial vehicle propulsion , auxiliary propulsion , advanced cryogenic engines, cryogenic fluid systems, nuclear thermal propulsion , and nuclear electric propulsion ; 2 space platforms, which include spacecraft on-board propulsion , and station keeping propulsion ; and 3 technology flight experiments, which include cryogenic orbital N2 experiment CONE , SEPS flight experiment, and cryogenic orbital H2 experiment COHE.
Centralized versus distributed propulsion. The functions and requirements of auxiliary propulsion systems are reviewed. None of the three major tasks attitude control, stationkeeping, and shape control can be performed by a collection of thrusters at a single central location. If a centralized system is defined as a collection of separated clusters, made up of the minimum number of propulsion units, then such a system can provide attitude control and stationkeeping for most vehicles.
A distributed propulsion system is characterized by more numerous propulsion units in a regularly distributed arrangement. Various proposed large space systems are reviewed and it is concluded that centralized auxiliary propulsion is best suited to vehicles with a relatively rigid core. These vehicles may carry a number of flexible or movable appendages.
A second group, consisting of one or more large flexible flat plates, may need distributed propulsion for shape control. There is a third group, consisting of vehicles built up from multiple shuttle launches, which may be forced into a distributed system because of the need to add additional propulsion units as the vehicles grow. The effects of distributed propulsion on a beam-like structure were examined. The deflection of the structure under both translational and rotational thrusts is shown as a function of the number of equally spaced thrusters. When two thrusters only are used it is shown that location is an important parameter.
The possibility of using distributed propulsion to achieve minimum overall system weight is also examined. Finally, an examination of the active damping by distributed propulsion is described. Expendable launch vehicle propulsion. The current status is reviewed of the U. The ELV propulsion technology areas where research, development, and demonstration are most needed are identified. Advanced space propulsion concepts. Recent program elements have included high energy density propellants, electrode less plasma thruster concepts, and low power laser propulsion technology.
A robust advanced technology program is necessary to develop new, cost-effective methods of spacecraft propulsion , and to continue to push the boundaries of human knowledge and technology. Unsteady hydrodynamics of blade forces and acoustic responses of a model scaled submarine excited by propeller's thrust and side-forces. This study presents the unsteady hydrodynamics of the excitations from a 5-bladed propeller at two rotating speeds running in the wake of a small-scaled submarine and the behavior of the submarine 's structure and acoustic responses under the propeller excitations.
Firstly, the propeller flow and submarine flows are independently validated. The propulsion of the hull-propeller is simulated using computational fluid dynamics CFD , so as to obtain the transient responses of the propeller excitations. Results show that 1 the propeller excitations are tonal at the propeller harmonics, and the propeller transversal force is bigger than vertical force.
Lastly, the critical rotating speeds of the submarine propeller are determined, which should be carefully taken into consideration when match the propeller with prime mover in the propulsion system. This work shows the importance of the propeller's tonal excitation and the breathing mode plus the bending modes in evaluating submarine 's noise radiation. Field resonance propulsion concept.
A propulsion concept was developed based on a proposed resonance between coherent, pulsed electromagnetic wave forms, and gravitational wave forms or space-time metrics. Using this concept a spacecraft propulsion system potentially capable of galactic and intergalactic travel without prohibitive travel times was designed. The propulsion system utilizes recent research associated with magnetic field line merging, hydromagnetic wave effects, free-electron lasers, laser generation of megagauss fields, and special structural and containment metals.
The research required to determine potential, field resonance characteristics and to evaluate various aspects of the spacecraft propulsion design is described. Ceramic components for MHD electrode. The component is suitable for use in the fabrication of MHD electrodes or as the current leadout portion of a composite electrode with other ceramic components.
A 3-dimensional global MHD simulation of the earth's magnetosphere was performed at a speed of over Gflops with an efficiency of The objective of this study was to perform a parametric evaluation of the performance and interface characteristics of a dense plasma focus DPF Electric Propulsion Apparatus. An electric propulsion machine includes an ion thruster having an annular discharge chamber housing an anode having a large surface area.
Log in to Wiley Online Library
The ion thruster includes flat annular ion optics with a small span to gap ratio. Optionally, a second electric propulsion thruster may be disposed in a cylindrical space disposed within an interior of the annulus. The state-of-the-art Propulsion Research Laboratory PRL serves as a leading national resource for advanced space propulsion research. Its purpose is to conduct research that will lead to the creation and development of innovative propulsion technologies for space exploration. The facility is the epicenter of the effort to move the U.