SEARCH · Search NASA

Results for “surface power systems”

Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

SourceResearch connectionFrom yearThrough year

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 613 records · Page 34

All sources NASA NTRS DOE OSTI

NASA NTRS2006

Novel Thermal Powered Technology for UUV Persistent Surveillance

Buoyancy Generation: Various technology attempts include melting a wax, which pushes directly against a piston (U.S. Patent 5,291,847) or against a bladder (Webb Research), using ammonia or Freon 21 (U.S. Patent 5,303,552), and using solar heat to expand an oil (www.space.com, April, 10, 2002). All these heat-activated buoyancy control designs have thus far proved impractical and have ultimately failed during repeated cycling in ocean testing. JPL has demonstrated fully reversible 10 C encapsulated wax phase change, which can be used to change buoyancy without electrical hydraulic pumps. This technique has greatly improved heat transfer and much better reversibility than previous designs. Power Generation: Ocean Thermal Energy Conversion (OTEC) systems have been designed that transfer deep, cold sea water to the surface to generate electricity using turbine cycles with ammonia or water as the working fluid. JPL has designed several UUV systems: 1) Using a propeller water turbine to generate power on a gliding submersible; 2) Employing a compact CO2 turbine cycle powered by moving through thermoclines; and 3) Using melted wax to directly produce power through a piston-geared generator.

submersible↗

DOE OSTI2022

Wound Field and Hybrid Synchronous Machines for EV Traction with Brushless Capacitive Rotor Field Excitation (Final Report)

This project focused on the development of wound field synchronous machines (WFSMs) and hybrid excitation synchronous machines (HESMs) with brushless capacitive power transfer for the field excitation. The target application for the machines developed is the main traction motor in electric vehicles. The magnetization in these types of machines is provided by a field winding on the rotor which is excited with DC current. The magnetization level in the machine can be varied by changing the magnitude of the field current. The variable magnetization or field is one of the key features of WFSMs. WFSMs are commonly used as generators however they have several attractive features for automotive traction applications. 1) No use of permanent magnet: Rare earth permanent magnets are primarily mined and processed in China. They have been subject to large price and supply variations and their export may be restricted during times of geopolitical tension. 2) Easy field weakening: Wound field synchronous machines have complete control of their field excitation. With proper design, this type of machine can electromagnetically have an infinite constant power speed range. 3) High power factor: With proper choice of the field excitation, WFSMs may be operated with high or even unity power factor. This potentially allows for the inverter connected to the stator winding to be downsized. In comparison induction machines and interior permanent magnet synchronous machines must supply reactive power to the stator increasing the kVA rating and cost of the inverter. 4) Reduced iron losses at high speed: By reducing the field excitation, the iron loss in the stator can be reduced. This is in comparison to interior permanent magnet synchronous machines which must use stator current to buck or reduce the flux produced by the permanent magnets. Generally, WFSMs have their highest efficiency at high speed. 5) Torque output at high temperatures: The magnetization provided by the field winding only depends on the field current and not on the field winding temperature. This is in contrast to permanent magnet machines where the permanent magnet flux decreases as the magnet temperature increases. Historically a number of approaches have been developed to provide DC current to the rotating field winding in WFSM’s including brushes and slip rings, low frequency brushless exciters, and high frequency rotary transformers and rectifiers. In this project, a different approach was used: brushless capacitive power transfer. Brushless capacitive power transfer uses two sets of rotating capacitors or electrodes in which an AC electric field is established by a high frequency inverter. A displacement current can flow through the airgap in the rotating capacitors which is rectified on the rotor using a diode bridge. The potential advantage of capacitive power transfer is that there is no need for heavy iron to guide magnetic flux. The electric flux lines terminate on the charges on the rotary capacitor surfaces. This should also limit the electric field outside the rotary capacitor airgaps. The main challenge with capacitive power transfer is that the capacitance and surface area of the rotating capacitors is small. Because capacitive power transfer systems are essentially a dual of a magnetic system, an Ampere per Hertz relationship is characteristic versus a Volts per Hertz relationship. A very high frequency power inverter must be used to provide sufficient excitation to the field winding. The concept of using capacitive power transfer to excite a high performance WFSM was initially developed in a previous U.S.A. Dept. of Energy project, DE-EE0006829. This project focused on increasing the power density of the WFSMs and reducing the cost and manufacturing complexity of the capacitive power transfer system. This project has demonstrated that WFSMs with brushless capacitive field power transfer can provide a high-power density and low-cost automotive powertrain technology.

33 ADVANCED PROPULSION SYSTEMS↗

NASA NTRS1967

Parametric analysis of radioisotope thermoelectric generators

A parametric analysis of a radioisotope-thermoelectric power generator is presented. A cylindrical heat-source geometry was assumed with either lead telluride or silicon-germanium thermoelectric elements located around the lateral surface of the fuel block. Generator performance, rather than overall power-system performance, was analyzed; that is, such mission dependent considerations as nuclear shielding, reentry protection, and power conditioning were not included.

James J. Ward↗

NASA NTRS1990

Technology needs of the Exploration Initiative

An overview of the U.S. Space Exploration Initiative (SEI) is presented. The two primary objectives of the initiative are a return to the moon to create a permanent lunar base and a human mission to Mars. Even though mission architectural concepts are not yet defined, previous studies indicate that the SEI will require developments in numerous areas, including advanced engines for space transportation, in-space assembly and construction to support permanent basing of exploration systems in space, and advanced surface operations capabilities including satisfactory levels of power and surface roving vehicles, and technologies to safely support human space operations of long duration. The process of mission definition has begun and it is shown that it is possible to identify a family of fundamental functional building blocks from which all SEI mission architectures will be constructed.

Aldrich, Arnold↗

NASA NTRS2017

The LEMUR 3 Limbed Climbing Robot

This paper introduces a new four-limbed robot, LEMUR 3, that has demonstrated climbing on cliff faces and smooth glass. Each limb on the robot consists of seven identical actuators in a serial chain. Each limb terminates in a single axis force sensor that allows various end effectors to be mounted and connected to the robot’s power and communication system. Microspine grippers were used for climbing the rocky surface and gecko adhesive grippers were used for the glass solar panels. All other hardware and much of the software was common for the two demonstrations. The robot’s mechanical, electrical, and software systems, various gripping devices, and field demonstrations are described. Limbed mobility is of interest to JPL and NASA because of its potential to access extreme terrain, including that on Mars and in microgravity environments.

Kennedy, Brett↗

NASA NTRSDate not supplied

Determining the Importance of In-Flight Treadmill Running Capabilities for Maintaining Astronaut Health and Performance

BACKGROUND: Physical deconditioning induced via spaceflight is most effectively attenuated through in-flight exercise training. Throughout its evolution, NASA has implemented advancements to in-flight exercise countermeasures, culminating in the triad of devices currently used aboard the International Space Station (ISS): a treadmill (T2), cycle ergometer (CEVIS), and resistance exercise device (ARED). Despite high-quality exercise devices and prescriptions, many crewmembers experience reductions in both aerobic capacity (VO2peak pre-post mean change: -10%) and strength (knee isokinetic pre-post mean change: -15%). As NASA moves towards exploration missions, which will impose greater size, power, and time constraints on exercise systems in addition to physically demanding surface extravehicular activities (EVAs), providing robust capabilities to protect crew health and performance should be prioritized. OVERVIEW: Future missions to the Lunar and Martian surfaces will include EVAs requiring ambulation and greater physical exertion than those in Apollo missions. While the exercise device concepts planned for exploration missions include resistive and aerobic capabilities, they do not allow for ambulation. Specifically, the countermeasure planned for Artemis Lunar transit is a flywheel device, which provides both exercise modalities through a single resistive cable. While more robust than the flywheel, the devices planned for the Lunar orbital space station, and subsequent Mars habitats, will provide distinct aerobic and resistance modalities capable of achieving high intensities. However, these modalities do not include a treadmill. Recent research suggests that greater in-flight running intensity and volume attenuate decrements in aerobic capacity and strength; however, this has not been experimentally confirmed. The Exploration Exercise Treadmill Requirements study is currently underway, aiming to determine the effects of exercising without a treadmill on aerobic capacity, strength, bone density, and sensorimotor function during long-duration spaceflight. DISCUSSION: Providing running capabilities on future exploration missions may help to maintain astronaut physical ability, reduce injury, and promote health. Studies quantifying the effects of using exploration exercise devices are in progress, which will help provide critical recommendations on whether a treadmill is a necessary component of the in-flight training regime. This presentation will discuss the capabilities of exploration exercise devices and the potential implications of not having running capabilities during long-duration spaceflight.

Alyssa N Varanoske↗

DOE OSTI2022

Autonomous light management system for a window and method of controlling light transmission

An autonomous light management system for a window includes an electrochromic film stack comprising an electrochromic layer on a first transparent electrode, an ion storage layer on a second transparent electrode, and an electrolyte sandwiched between the ion storage and electrochromic layers. The electrochromic film stack exhibits a transmissive state or an absorptive state depending on charging or discharging of the electrochromic layer. The light management system further comprises an array of power units disposed on a front surface of the electrochromic film stack, where each power unit comprises at least one solar microcell. Collectively, the solar microcells cover an area no greater than about 6% of a total area of the front surface. The array of power units is configured to control the charging and discharging of the electrochromic layer, thereby manipulating light transmission through the electrochromic film stack.

Yoder, Mikayla A.↗

DOE OSTI2025

Advanced Microstructured BaTiO 3 -Embedded PVDF–HFP/PEO Film for Enhanced Triboelectric Interface in Self-Sufficient Energy Generation and Sensing

The global reliance on fossil fuels and natural gas has largely dominated the energy production field, but due to finite resource depletion and escalating greenhouse gas emissions, the immediate exploration of sustainable energy alternatives to mitigate climate change and ensure resource security has been a major concern. There has been extensive research into other more renewable methods of energy production, such as wind and hydropower. Of these current energy generation types, there are many areas of untapped potential from the mechanical movements generated ambiently not only in the large scale of power generation but also on a smaller scale. The piezoelectric and triboelectric effects are phenomena where these ambient mechanical movements can generate electrical energy. Developing a hybrid system that leverages both mechanical stress and surface charges presents an ideal opportunity to exploit these untapped energy sources. Producing a hybrid PVDF–HFP/PEO film with perovskite BaTiO 3 (BTO) enables ambient power harvesting from both mechanical movement and surface charge. The optimized cell produced a potential of up to 15 V and a current of 200 nA with a 68 kΩ resistor, a substantial increase from a base system with an average of 2.1 V and 40 nA. These hybrid TENGs offer significant potential for energy harvesting in small-scale applications, such as health monitoring devices and indicators in electric circuits.

Ybarra, Rigobert [University of Texas Rio Grande V↗

NASA NTRS2021

Thermal Systems Modeling of Chemical Integrated Power Source (CHIPS) to Survive Lunar Night Environments

This paper presents the results of the systems level thermal modeling for a conceptual Chemical Heat Integrated Power Source (CHIPS). This proposed system offers a combined thermal and electrical power source to support survival of spacecraft operating in extreme low temperature lunar environments, without the use of radioisotope-based sources. A conceptual design study has been completed for this system, that uses heat generated by an exothermic chemical reaction in place of radioisotope or electrical heat sources. The goal of the study was to evaluate the feasibility of such as system through thermodynamic and chemical analysis and thermal modeling, and to identify technology gaps to inform a technology development and maturation plan. The specific technical objectives focused on delivery of 90-100 Wth thermal power and 30-40 We electrical power for 336 hours to a representative Commercial Lunar Payload Services (CLPS) lander, to support lunar surface survival and limited operations through a lunar night. The total system mass was targeted at ≤50 kg. A highly exothermic chemical reaction system is used to generate on-board electrical power for spacecraft systems, and thermal power to maintain critical spacecraft/lander systems within their allowable flight temperature (AFTs). Based on the very high energy content of the chemical reaction system, a much higher amount of heat per unit mass can be delivered to the spacecraft, relative to a rechargeable lithium-ion battery and electrical heater(s). Since radioisotope heaters or generators are not used, the system will be orders of magnitude lower in cost than a radioisotope heating/power unit, without the attendant regulatory complexities. As part of the CHIPS concept, a fraction of the thermal power generated is converted to electrical power via an appropriate thermal-to-electric converter technology (such as a free piston Stirling converter or a thermoelectric generator module), to provide power to critical loads. This approach is ideally suited to support operation of commercial landers (e.g., via the CLPS program). In most cases, these landers are only designed to operate during a portion of the lunar day, with no provision for survival through the lunar night. By supporting lunar night survival, a mission can be extended through the lunar night and at least into another lunar day, thus turning a nominal eight-day mission into a 36-day mission. Therefore, the current system demonstration will focus on scalability to support at least 336 hours (one lunar night) of continuous thermal and electrical power generation. Although initially targeted to support lunar equatorial landings, the technology is extensible to missions at the lunar poles, other extreme environments in the Solar System or even air-independent applications on Earth (e.g., ocean exploration).

West, William↗

NASA NTRS1999

Boiling Heat Transfer Measurements on Highly Conductive Surfaces Using Microscale Heater and Temperature Arrays

Two systems have been developed to study boiling heat transfer on the microscale. The first system utilizes a 32 x 32 array of diodes to measure the local temperature fluctuations during boiling on a silicon wafer heated from below. The second system utilizes an array of 96 microscale heaters each maintained at constant surface temperature using electronic feedback loops. The power required to keep each heater at constant temperature is measured, enabling the local heat transfer coefficient to be determined. Both of these systems as well as some preliminary results are discussed.

Kim, J.↗

NASA NTRS2021

Thermal Systems Modeling of Chemical Heat Integrated Power Source (CHIPS) to Survive Lunar Night Environments

This paper presents the results of the systems level thermal modeling for a conceptual Chemical Heat Integrated Power Source (CHIPS). This proposed system offers a combined thermal and electrical power source to support survival of spacecraft operating in extreme low temperature lunar environments, without the use of radioisotope-based sources. A conceptual design study has been completed for this system, that uses heat generated by an exothermic chemical reaction in place of radioisotope or electrical heat sources. The goal of the study was to evaluate the feasibility of such a system through thermodynamic and chemical analysis and thermal modeling, and to identify technology gaps to inform a technology development and maturation plan. The specific technical objectives focused on delivery of 90 to 100 Wth thermal power and 30 to 40 We electrical power for 336 hours to a representative Commercial Lunar Payload Services (CLPS) lander, to support lunar surface survival and limited operations through a lunar night. The total system mass was targeted at ≤50 kg. A highly exothermic chemical reaction system is used to generate on-board electrical power for spacecraft systems, and thermal power to maintain critical spacecraft/lander systems within their allowable flight temperature (AFTs). Based on the very high energy content of the chemical reaction system, a much higher amount of heat per unit mass can be delivered to the spacecraft, relative to a rechargeable lithium-ion battery and electrical heater(s). Since radioisotope heaters or generators are not used, the system will be orders of magnitude lower in cost than a radioisotope heating/power unit, without the attendant regulatory complexities. As part of the CHIPS concept, a fraction of the thermal power generated is converted to electrical power via an appropriate thermal-to-electric converter technology (such as a free piston Stirling converter or a thermoelectric generator module), to provide power to critical loads. This approach is ideally suited to support operation of commercial landers (e.g., via the CLPS program). In most cases, these landers are only designed to operate during a portion of the lunar day, with no provision for survival through the lunar night. By supporting lunar night survival, a mission can be extended through the lunar night and at least into another lunar day, thus turning a nominal eight-day mission into a 36-day mission. Therefore, the current system demonstration will focus on scalability to support at least 336 hours (one lunar night) of continuous thermal and electrical power generation. Although initially targeted to support lunar equatorial landings, the technology is extensible to missions at the lunar poles, other extreme environments in the Solar System or even air-independent applications on Earth (e.g., ocean exploration).

West, William↗

DOE OSTI2022

Single-Phase Dielectric Fluid Thermal Management for Power-Dense Automotive Power Electronics

This paper describes the design and performance of a dielectric fluid cooling concept for automotive power electronics. The concept combines a low-thermal-resistance package (which eliminates metalized ceramic substrates) with a high-performance convective cooling strategy (slot jets impinging on finned surfaces). Modeling was first used to design the cooling system to maximize thermal performance and minimize pumping power. Additionally, a prototype was then fabricated, and experiments were conducted to validate the model predictions using three fluids at various fluid flow rates (16.7 cm 3 /s [1 L/min] to 68.3 cm 3 /s [4.1 L/min]) and inlet temperatures (30C and 70C). The final design was compact (120-cm 3 total volume, including heat exchanger and conceptual power modules) and cooled 12 devices (e.g., silicon carbide). The validated model was then used to predict the junction-to-fluid thermal resistance and pumping power for various conditions, including 40C fluid temperature. The results predict thermal resistance values as low as 19 mm 2 K/W are possible using the dielectric fluid cooling approach. The dielectric fluid cooling system is predicted to provide thermal resistance and pumping power values that are approximately 56% and 90% lower, respectively, compared to an automotive power electronics cooling system.

30 DIRECT ENERGY CONVERSION↗

DOE OSTI2021

Preventing stent failure using adaptive shear responsive endovascular implant

A stent apparatus, system, and method that senses wall shear stress by measuring fluid flow at localized areas within the stent, that processes measured information through an integrated circuit, and selectively sends power to mechanically controllable stent surfaces which results in localized geometric changes. In various embodiments the stent apparatus, system, and method sends data to outside the body in real time.

Mukerjee, Erik V.↗

DOE OSTI2024

Preventing stent failure using adaptive shear responsive endovascular implant

Mukerjee, Erik V.↗

NASA NTRS1980

Space shuttle status

Technology problems relating to the shuttle thermal protection system and the auxiliary power units for flight control of engine gimbaling and aero surfaces are examined as well as yet unresolved difficulties associated with the main engine, external tank doors, and the payload bay doors. Concepts for launch crew escape and for flight inspection are discussed, and the orbital flight test drivers are identified. The majority of OFT objectives can be accomplished in a success oriented four flight program. Carry over will be accommodated in the operational phase with a mini-DFI package. Primary shuttle systems requiring additional testings are (1) aerodynamics (forward CG); (2) thermal control system (high beta); (3) payload deployment and retrieval system (retrieval, a maximum weight, and proximity operations); (4) SSME throttling to 109%; and (5) SSME nozzle entry aerodynamic heating (up elevon/body flap position at hypersonic velocities).

Slayton, D. K.↗

DOE OSTI2022

Characterizing the Number of Kinesin Motors Bound to Microtubules in the Gliding Motility Assay Using FLIC Microscopy [Book Chapter]

Intracellular transport by kinesin motors moving along their associated cytoskeletal filaments, microtubules, is essential to many biological processes. This active transport system can be reconstituted in vitro with the surface-adhered motors transporting the microtubules across a planar surface. In this geometry, the kinesin-microtubule system has been used to study active self-assembly, to power microdevices, and to perform analyte detection. Fundamental to these applications is the ability to characterize the interactions between the surface tethered motors and microtubules. Further, Fluorescence Interference Contrast (FLIC) microscopy can illuminate the height of the microtubule above a surface, which, at sufficiently low surface densities of kinesin, also reveals the number, locations, and dynamics of the bound motors.

59 BASIC BIOLOGICAL SCIENCES↗

NASA NTRS2019

Internal Electrostatic Discharge Testing of Inert Solid Rocket Motor Materials

Jupiter’s moon Europa is believed to have a global liquid-water ocean beneath its icy surface. As such, it is a highly interesting destination for explorers seeking signs of life outside of Earth. This interest has given rise to the Europa Lander Mission [Hand, et al., 2017]. The central goal of the Europa Lander Mission is to place a stationary lander on Europa and make surface and sub-surface measurements, dramatically improving understanding of this Jovian moon, and potentially detecting signs of life.Placing a lander on Europa will require multiple spacecraft elements deployed across a multi-year mission timeline. Some of the key elements include: a large payload capacity rocket, such as the Space Launch System (SLS), capable of providing direct Jupiter orbit insertion; a solar-powered carrier; a de-orbit system; a sky crane landing system; and, of course, the surface lander. A noteworthy fact is that the current design requires a large solid rocket motor to provide the necessary braking thrust for the de-orbit stage. While solid rocket motors have been used extensively by NASA during launch, in-space use has been limited. In addition to the normal challenges associated with a long-distance planetary mission, the Europa Lander Mission must also contend with the high-radiation environment associated with the Jovian system. The size of Jupiter, combined with its magnetic field strength, and rotation speed, result in a harsh radiation environment composed of high energy charged particles (ions and electrons) as well as high-temperature plasmas [de Soria-Santacruz Pich, 2016]. Due to this high-radiation environment, each component of the Europa Lander spacecraft must be evaluated to determine its radiation dose tolerance and its likelihood for experiencing electrostatic charging (and discharging). In general, metal components in a Jovian environment do not pose a concern for radiation degradation; in fact, metal structures and closeouts can act as radiation shielding for the more sensitive components. Charging of a metal component is only an issue if the component is not properly grounded to the spacecraft chassis. However, electrically insulating materials, such as polymers, are subject to radiation degradation as well as surface and internal charging, and therefore require extra scrutiny. The focus of this paper will be on the insulating materials that are commonly used inside solid rocket motors. The special application of a solid rocket motor used in space after a relatively long duration flight, combined with the high energy electron environment in the Jovian system, raises concerns about the possibility of significant charging and discharging leading to reduced performance.

Schneider, Todd A.↗

NASA NTRS1997

A Technique for Transient Thermal Testing of Thick Structures

A new open-loop heat flux control technique has been developed to conduct transient thermal testing of thick, thermally-conductive aerospace structures. This technique uses calibration of the radiant heater system power level as a function of heat flux, predicted aerodynamic heat flux, and the properties of an instrumented test article. An iterative process was used to generate open-loop heater power profiles prior to each transient thermal test. Differences between the measured and predicted surface temperatures were used to refine the heater power level command profiles through the iteration process. This iteration process has reduced the effects of environmental and test system design factors, which are normally compensated for by closed-loop temperature control, to acceptable levels. The final revised heater power profiles resulted in measured temperature time histories which deviated less than 25 F from the predicted surface temperatures.

Horn, Thomas J.↗