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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.

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At least 343 records · Page 19
All sourcesNASA NTRSDOE OSTI
NASA NTRS2018

Space Technology Mission Directorate: Game Changing Development Program: Rapid Analysis and Manufacturing Propulsion Technology (RAMPT)

Technology Overview: The RAMPT (Rapid Analysis and Manufacturing Propulsion Technology) project will develop and advance large scale light-weight multi-metallic freeform manufacturing and composite overwrap techniques and analysis capabilities required to implement them to reduce design and fabrication cycles for regeneratively-cooled liquid rocket engine components; RAMPT will reduce design, fabrication, assembly schedules while allowing for reduced parts, increased reliability, significant weight reduction and a healthy American supply chain. Four technology areas developed: 1) Freeform Blown Powder Nozzle; 2) Composite overwrap structural jacket; 3) Bimetallic radial deposition for manifolds; 4) Modeling and analysis tools for Additive and Regen design. Exploration & Science Impact: Addresses longest lead, highest cost and heaviest component in engine; Applicable to Lunar Lander Engine, Booster Engines, Upper Stage Engines, and NTP (Nuclear Thermal Propulsion) Technology; Public-private partnerships with specialty industry vendors, government partners, Commercial Crew, and infusion into commercial space companies and manufacturers; SSTIP (NASA's Strategic Space Technology Investment Plan) Core Investment Area - Launch Propulsion Systems (TA01 (NASA Technology Area 01); Lightweight Space Structures and Materials (TA12); Manufacturing (TA12).

RAMPT↗
NASA NTRS1999

Miniature Heat Transport System for Nanosatellite Technology

The scientific understanding of key physical processes between the Sun and the Earth require simultaneous measurements from many vantage points in space. Nano-satellite technologies will enable a class of constellation missions for the NASA Space Science Sun-Earth Connections. This recent emphasis on the implementation of smaller satellites leads to a requirement for development of smaller subsystems in several areas. Key technologies under development include: advanced miniaturized chemical propulsion; miniaturized sensors; highly integrated, compact electronics; autonomous onboard and ground operations; miniatures low power tracking techniques for orbit determination; onboard RF communications capable of transmitting data to the ground from far distances; lightweight efficient solar array panels; lightweight, high output battery cells; lightweight yet strong composite materials for the nano-spacecraft and deployer-ship structures. These newer smaller systems may have higher power densities and higher thermal transport requirements than seen on previous small satellites. Furthermore, the small satellites may also have a requirement to maintain thermal control through extended earth shadows, possibly up to 8 hours long. Older thermal control technology, such as heaters, thermostats, and heat pipes, may not be sufficient to meet the requirements of these new systems. Conversely, a miniature two-phase heat transport system (Mini-HTS) such as a Capillary Pumped Loop (CPL) or Loop Heat Pipe (LBP) is a viable alternative. A Mini-HTS can provide fine temperature control, thermal diode action, and a highly efficient means of heat transfer. The Mini-HTS would have power capabilities in the range of tens of watts or less and provide thermal control over typical spacecraft ranges. The Mini-HTS would allow the internal portion of the spacecraft to be thermally isolated from the external radiator, thus protecting the internal components from extreme cold temperatures during an eclipse. The Mini-HTS would transport the beat from these components to a radiator during their operational modes, and it would be shutdown during non-operational or eclipse modes. Shutdown of the Mini-HTS would be accomplished with small heaters and has been successfully demonstrated on numerous occasions, both in the lab and on flight experiments. Efforts are now underway to miniaturize two-phase heat transport systems for the Nanosatellite project, with potential application to other small satellite programs. 'ne goal of this project is to design, build, and test miniature heat transport systems (MHTS) that would demonstrate the feasibility of a small Capillary Pumped Loop (CPL) or Loop Heat Pipe (LBP).

Douglas, Donya M,↗
NASA NTRS2013

Neutron Characterization for Additive Manufacturing

Oak Ridge National Laboratory (ORNL) is leveraging decades of experience in neutron characterization of advanced materials together with resources such as the Spallation Neutron Source (SNS) and the High Flux Isotope Reactor (HFIR) shown in Fig. 1 to solve challenging problems in additive manufacturing (AM). Additive manufacturing, or three-dimensional (3-D) printing, is a rapidly maturing technology wherein components are built by selectively adding feedstock material at locations specified by a computer model. The majority of these technologies use thermally driven phase change mechanisms to convert the feedstock into functioning material. As the molten material cools and solidifies, the component is subjected to significant thermal gradients, generating significant internal stresses throughout the part (Fig. 2). As layers are added, inherent residual stresses cause warping and distortions that lead to geometrical differences between the final part and the original computer generated design. This effect also limits geometries that can be fabricated using AM, such as thin-walled, high-aspect- ratio, and overhanging structures. Distortion may be minimized by intelligent toolpath planning or strategic placement of support structures, but these approaches are not well understood and often "Edisonian" in nature. Residual stresses can also impact component performance during operation. For example, in a thermally cycled environment such as a high-pressure turbine engine, residual stresses can cause components to distort unpredictably. Different thermal treatments on as-fabricated AM components have been used to minimize residual stress, but components still retain a nonhomogeneous stress state and/or demonstrate a relaxation-derived geometric distortion. Industry, federal laboratory, and university collaboration is needed to address these challenges and enable the U.S. to compete in the global market. Work is currently being conducted on AM technologies at the ORNL Manufacturing Demonstration Facility (MDF) sponsored by the DOE's Advanced Manufacturing Office. The MDF is focusing on R&D of both metal and polymer AM pertaining to in-situ process monitoring and closed-loop controls; implementation of advanced materials in AM technologies; and demonstration, characterization, and optimization of next-generation technologies. ORNL is working directly with industry partners to leverage world-leading facilities in fields such as high performance computing, advanced materials characterization, and neutron sciences to solve fundamental challenges in advanced manufacturing. Specifically, MDF is leveraging two of the world's most advanced neutron facilities, the HFIR and SNS, to characterize additive manufactured components.

Watkins, Thomas↗
NASA NTRS2001

Silicon Nitride Plates for Turbine Blade Application: FEA and NDE Assessment

Engine manufacturers are continually attempting to improve the performance and the overall efficiency of internal combustion engines. The thermal efficiency is typically improved by raising the operating temperature of essential engine components in the combustion area. This reduces the heat loss to a cooling system and allows a greater portion of the heat to be used for propulsion. Further improvements can be achieved by diverting part of the air from the compressor, which would have been used in the combustor for combustion purposes, into the turbine components. Such a process is called active cooling. Increasing the operating temperature, decreasing the cooling air, or both can improve the efficiency of the engine. Furthermore, lightweight, strong, tough hightemperature materials are required to complement efficiency improvement for nextgeneration gas turbine engines that can operate with minimum cooling. Because of their low-density, high-temperature strength, and thermal conductivity, ceramics are being investigated as potential materials for replacing ordinary metals that are currently used for engine hot section components. Ceramic structures can withstand higher operating temperatures and other harsh environmental factors. In addition, their low densities relative to metals helps condense component mass (ref. 1). The objectives of this program at the NASA Glenn Research Center are to develop manufacturing technology, a thermal barrier coating/environmental barrier coating (TBC/EBC), and an analytical modeling capability to predict thermomechanical stresses, and to do minimal burner rig tests of silicon nitride (Si3N4) and SiC/SiC turbine nozzle vanes under simulated engine conditions. Furthermore, and in support of the latter objectives, an optimization exercise using finite element analysis and nondestructive evaluation (NDE) was carried out to characterize and evaluate silicon nitride plates with cooling channels.

Abdul-Aziz, Ali↗
NASA NTRS2010

Thermal Analysis of the Advanced Technology Large Aperture Space Telescope (ATLAST) 8 Meter Primary Mirror

The Advanced Technology Large Aperture Space Telescope (ATLAST) preliminary design concept consists of an 8 meter diameter monolithic primary mirror enclosed in an insulated, optical tube with stray light baffles and a sunshade. ATLAST will be placed in orbit about the Sun-Earth L2 and will experience constant exposure to the sun. The insulation on the optical tube and sunshade serve to cold bias the telescope which helps to minimize thermal gradients. The primary mirror will be maintained at 280K with an active thermal control system. The geometric model of the primary mirror, optical tube, sun baffles, and sunshade was developed using Thermal Desktop(R) SINDA/FLUINT(R) was used for the thermal analysis and the radiation environment was analyzed using RADCAD(R). A XX node model was executed in order to characterize the static performance and thermal stability of the mirror during maneuvers. This is important because long exposure observations, such as extra-solar terrestrial planet finding and characterization, require a very stable observatory wave front. Steady state thermal analyses served to predict mirror temperatures for several different sun angles. Transient analyses were performed in order to predict thermal time constant of the primary mirror for a 20 degree slew or 30 degree roll maneuver. This paper describes the thermal model and provides details of the geometry, thermo-optical properties, and the environment which influences the thermal performance. All assumptions that were used in the analysis are also documented. Parametric analyses are summarized for design parameters including primary mirror coatings and sunshade configuration. Estimates of mirror heater power requirements are reported. The thermal model demonstrates results for the primary mirror heated from the back side and edges using a heater system with multiple independently controlled zones.

Hornsby, Linda↗
NASA NTRS2010

Two-Phase Thermal Switching System for a Small, Extended Duration Lunar Science Platform

Issue: extended duration lunar science platforms, using solar/battery or radioisotope power, require thermal switching systems that: a) Provide efficient cooling during the 15-earth-day 390 K lunar day; b) Consume minimal power during the 15-earth-day 100 K lunar night. Objective: carry out an analytical study of thermal switching systems that can meet the thermal requirements of: a) International Lunar Network (ILN) anchor node mission - primary focus; b) Other missions such as polar crater landers. ILN Anchor Nodes: network of geophysical science platforms to better understand the interior structure/composition of the moon: a) Rationale: no data since Apollo seismic stations ceased operation in 1977; b) Anchor Nodes: small, low-power, long-life (6-yr) landers with seismographic and a few other science instruments (see next chart); c) WEB: warm electronics box houses ILN anchor node electronics/batteries. Technology Need: thermal switching system that will keep the WEB cool during the lunar day and warm during the lunar night.

Bugby, D.↗
NASA NTRS2014

Nuclear Thermal Propulsion (NTP): A Proven, Growth Technology for Fast Transit Human Missions to Mars

The "fast conjunction" long surface stay mission option was selected for NASA's recent Mars Design Reference Architecture (DRA) 5.0 study because it provided adequate time at Mars (approx. 540 days) for the crew to explore the planet's geological diversity while also reducing the "1-way" transit times to and from Mars to approx. 6 months. Short transit times are desirable in order to reduce the debilitating physiological effects on the human body that can result from prolonged exposure to the zero-gravity (0-gE) and radiation environments of space. Recent measurements from the RAD detector attached to the Curiosity rover indicate that astronauts would receive a radiation dose of approx. 0.66 Sv (approx. 66 rem)-the limiting value established by NASA-during their 1-year journey in deep space. Proven nuclear thermal rocket (NTR) technology, with its high thrust and high specific impulse (Isp approx. 900 s), can cut 1-way transit times by as much as 50 percent by increasing the propellant capacity of the Mars transfer vehicle (MTV). No large technology scale-ups in engine size are required for these short transit missions either since the smallest engine tested during the Rover program-the 25 klbf "Pewee" engine is sufficient when used in a clustered arrangement of three to four engines. The "Copernicus" crewed MTV developed for DRA 5.0 is a 0-gE design consisting of three basic components: (1) the NTP stage (NTPS); (2) the crewed payload element; and (3) an integrated "saddle truss" and LH2 propellant drop tank assembly that connects the two elements. With a propellant capacity of approx. 190 t, Copernicus can support 1-way transit times ranging from approx. 150 to 220 days over the 15-year synodic cycle. The paper examines the impact on vehicle design of decreasing transit times for the 2033 mission opportunity. With a fourth "upgraded" SLS/HLV launch, an "in-line" LH2 tank element can be added to Copernicus allowing 1-way transit times of 130 days. To achieve 100 to 120 day transit times, Copernicus' saddle truss/drop tank assembly is replaced by a "star truss" assembly with paired modular drop tanks to further increase the vehicle's propellant capacity. The HLV launch count increases (from approx. 5 to 7) and a fourth engine is needed to reduce total mission burn time and gravity losses. Using a "split mission" approach, the NTPS, in-line tank and the saddle truss/LH2 drop tank elements can be configured as a pre-deployed Earth Return Vehicle/propellant tanker supporting 90-day crewed mission transits. The split mission approach also eliminates the need for on-orbit assembly. Mission scenario descriptions, key features and operational characteristics for five different vehicle configurations are presented.

Borowski, Stanley K.↗
NASA NTRS1993

Evolution of miniature detectors and focal plane arrays for infrared sensors

Sensors that are sensitive in the infrared spectral region have been under continuous development since the WW2 era. A quest for the military advantage of 'seeing in the dark' has pushed thermal imaging technology toward high spatial and temporal resolution for night vision equipment, fire control, search track, and seeker 'homing' guidance sensing devices. Similarly, scientific applications have pushed spectral resolution for chemical analysis, remote sensing of earth resources, and astronomical exploration applications. As a result of these developments, focal plane arrays (FPA) are now available with sufficient sensitivity for both high spatial and narrow bandwidth spectral resolution imaging over large fields of view. Such devices combined with emerging opto-electronic developments in integrated FPA data processing techniques can yield miniature sensors capable of imaging reflected sunlight in the near IR and emitted thermal energy in the Mid-wave (MWIR) and longwave (LWIR) IR spectral regions. Robotic space sensors equipped with advanced versions of these FPA's will provide high resolution 'pictures' of their surroundings, perform remote analysis of solid, liquid, and gas matter, or selectively look for 'signatures' of specific objects. Evolutionary trends and projections of future low power micro detector FPA developments for day/night operation or use in adverse viewing conditions are presented in the following test.

Watts, Louis A.↗
NASA NTRS2007

Thermal Characterization Study of Lithium-Ion Cells

The primary challenge in designing a full scale lithium-ion (Li-ion) battery system is safety under both normal operating as well as abusive conditions. The normal conditions involve expected charge/discharge cycles and it is known that heat evolves in batteries during those cycles. This is a major concern in the design for high power applications and careful thermal management is necessary to alleviate this concern. An emerging thermal measurement technology, such as the electrochemical calorimetric of batteries, will aid in the development of advanced, safe battery system. To support this technology, several "commercial-off-the-shelf" (COTS) Li-ion cells with different chemistries and designs are being evaluated for different cycling regimes at a given operating temperature. The Accelerated Rate Calorimeter (ARC)-Arbin cycler setup is used to measure the temperature, voltage, and current of the cells at different charge/discharge rates. Initial results demonstrated good cell cyclability. During the cycle testing, the cell exhibited an endothermic cooling in the initial part of the charge cycle. The discharge portion of the cycle is exothermic during the entire discharge period. The presence of an endothermic reaction indicates a significant entropy effect during the beginning of charge cycle. Further studies will be performed to understand the thermal characteristics of the Li-ion cells at the different operating conditions. The effects on the thermal response on cell aging and states-of-charge will also be identified.

Britton, Doris L.↗
NASA NTRS1993

Vision-aided Monitoring and Control of Thermal Spray, Spray Forming, and Welding Processes

Vision is one of the most powerful forms of non-contact sensing for monitoring and control of manufacturing processes. However, processes involving an arc plasma or flame such as welding or thermal spraying pose particularly challenging problems to conventional vision sensing and processing techniques. The arc or plasma is not typically limited to a single spectral region and thus cannot be easily filtered out optically. This paper presents an innovative vision sensing system that uses intense stroboscopic illumination to overpower the arc light and produce a video image that is free of arc light or glare and dedicated image processing and analysis schemes that can enhance the video images or extract features of interest and produce quantitative process measures which can be used for process monitoring and control. Results of two SBIR programs sponsored by NASA and DOE and focusing on the application of this innovative vision sensing and processing technology to thermal spraying and welding process monitoring and control are discussed.

Agapakis, John E.↗
NASA NTRS2023

Long Life Molten Salt Battery for NASA Venus Application

A development program is being conducted at Advanced Thermal Batteries (ATB) to create a low discharge rate, long life, molten salt battery for a NASA Venus surface probe. Battery goals are 60 days continuous operation at +25V +0/-6 volts and -25V +6/-0 Volts under severe environments of 465°C, 92 atm pressure, and corrosive sulfur dioxide in a super critical carbon dioxide atmosphere. Conveniently, molten salt thermal battery electrochemistry starts to operate efficiently at 330°C. However, a major barrier to direct application of existing thermal battery technology is the high self-discharge rate, resulting in lifetimes in only minutes, not days. The best performance to date, which meets the required voltage regulation, has been a lithium silicon (LiSi) alloy anode discharging through all three voltage plateau versus an iron monosulfide (FeS) cathode. In order to perform reproducibly, additional engineering controls within the battery design are required to limit cell–to–cell parasitic discharge mechanisms. Results of these trials have improved the efficiency and manufacturability of the design.

Thermal Battery↗
NASA NTRS1992

Nuclear thermal propulsion transportation systems for lunar/Mars exploration

Nuclear thermal propulsion technology development is underway at NASA and DoE for Space Exploration Initiative (SEI) missions to Mars, with initial near-earth flights to validate flight readiness. Several reactor concepts are being considered for these missions, and important selection criteria will be evaluated before final selection of a system. These criteria include: safety and reliability, technical risk, cost, and performance, in that order. Of the concepts evaluated to date, the Nuclear Engine for Rocket Vehicle Applications (NERVA) derivative (NDR) is the only concept that has demonstrated full power, life, and performance in actual reactor tests. Other concepts will require significant design work and must demonstrate proof-of-concept. Technical risk, and hence, development cost should therefore be lowest for the concept, and the NDR concept is currently being considered for the initial SEI missions. As lighter weight, higher performance systems are developed and validated, including appropriate safety and astronaut-rating requirements, they will be considered to support future SEI application. A space transportation system using a modular nuclear thermal rocket (NTR) system for lunar and Mars missions is expected to result in significant life cycle cost savings. Finally, several key issues remain for NTR's, including public acceptance and operational issues. Nonetheless, NTR's are believed to be the 'next generation' of space propulsion systems - the key to space exploration.

Clark, John S.↗
NASA NTRS2019

NASA Thermal Recovery Energy Efficient System (TREES) for Aircraft Exergy Optimization

Future air vehicles will increasingly incorporate electrical powertrains that require very tight integration of power, propulsion, thermal, and airframe technologies. These complex and highly integrated sub-systems present a new exergy utilization and thermo-economics challenge due to the significant and highly distributed low-grade waste heat being produced. One system-wide solution is proposed that utilizes acoustic thermal energy conversion technologies to simultaneously provide thermal management and waste energy recycling for the entire vehicle. This system level solution serves to optimize aircraft exergy utilization.

Dyson, Rodger↗
NASA NTRS1972

Beryllium heat shield technology in the area of thermal protection devices

For future space applications, it is important that thermal protection systems be reusable for space shuttle flights. Beryllium offers a unique combination of properties for use as a heat shield material (stiffness, lightweight, ability to absorb heat). In order to adequately test these properties, it was necessary to fabricate heat shields. The concept used was a two-section test panel 99.1 x 99.1 cm (39 x 39 inch) with each section made of two 0.051 cm (0.020 inch) thick beryllium corrugations brazed together as a mirror image, with titanium (Ti-6Al-4V) used as standoffs to support the panel structure. The work prior to fabrication included brazability of both beryllium and titanium, forming of beryllium and titanium, machining processes involving beryllium and chem-milling beryllium. Sub-scale samples were made of all details before actual fabrication of the large panel. The full scale test panel was hot-formed at 950 K, chem-milled to 0.041 + or - 0.005 cm (0.016 + or - 0.002 inches), trimmed, vacuum brazed, drilled and assembled.

Muhl, A. E.↗
NASA NTRS1973

A Radiosonde Thermal Sensor Technique for Measurement of Atmospheric Turbulence

A system was developed to measure vertical profiles of microthermal turbulence in the free atmosphere. It combines thermal sensor technology with radiosonde balloon systems. The resultant data set from each thermosonde flight is a profile of the strength and distribution of microthermal fluctuations which act as tracers for turbulence. The optical strength of this turbulence is computed and used to predict optical and laser beam propagation statistics. A description of the flight payload, examples of turbulence profiles and comparison with simultaneous stellar observations are included.

Bufton, J. L.↗
NASA NTRS1975

A radiosonde thermal sensor technique for measurement of atmospheric turbulence

A new system was developed to measure vertical profiles of microthermal turbulence in the free atmosphere. It combines thermal sensor technology with radiosonde balloon systems. The resultant data set from each thermosonde flight is a profile of the strength and distribution of microthermal fluctuations which act as tracers for turbulence. The optical strength of this turbulence is computed and used to predict optical and laser beam propagation statistics. A description of the flight payload, examples of turbulence profiles, and comparison with simultaneous stellar observations are included.

Bufton, J. L.↗
NASA NTRS1981

Thermal infrared remote sensing of surface features for renewable resource applications

The subjects of infrared remote sensing of surface features for renewable resource applications is reviewed with respect to the basic physical concepts involved at the Earth's surface and up through the atmosphere, as well as the historical development of satellite systems which produce such data at increasingly greater spatial resolution. With this general background in hand, the growth of a variety of specific renewable resource applications using the developing thermal infrared technology are discussed, including data from HCMM investigators. Recommendations are made for continued growth in this field of applications.

Welker, J. E.↗
NASA NTRS1986

Space energy, power, and propulsion committee assessment

Energy conversion technology and thermal management for space platforms are addressed using the NASA Space Station as an example. The Space Station IOC configuration includes the use of solar PV and solar dynamic conversion techniques to satisfy the 75-kWe requirement and plans to produce over 300 kWe with the addition of dynamic modules. Nuclear reactors will probably be used to provide the higher energy requirements for future Space Stations in the 1-MW and higher levels.

Mullin, J. P.↗