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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 1,225 records · Page 68
All sourcesNASA NTRSDOE OSTI
NASA NTRS1996

Lessons Learned From the Flight of the NASA In-Step Cryo System Experiment

The Cryo System Experiment was developed to validate in near zero-g space a 65 K cryogenic system for focal planes, optics, or other imaging instruments that require continuous cryogenic cooling. Two key cryogenic technologies, designed to improve performance of systems for scientific, commercial and defense applications in space, were successfully demonstrated on a February 1995 Shuttle mission. The two were a 2-watt 65 K long-life low- vibration Stirling cooler and a diode oxygen heat pipe thermal switch. Lessons learned are presented.

cryogenics↗
NASA NTRS2020

2019 NASA Division of Space Life and Physical Sciences Research and Applications Fluid Physics Workshop Report

On October 16 and 17, 2019, NASA’s Space Life and Physical Sciences Research and Applications (SLPSRA) Division held the 2019 NASA SLPSRA Fluid Physics Workshop at the Glenn Research Center in Cleveland, Ohio. Researchers from academia, industry, and Government agencies gathered to provide recommendations to NASA on exploration-related microgravity challenges in multiphase systems and thermal transport processes. The goal of the workshop was to identify overarching future research themes relevant to NASA’s exploration goals in three key areas: (1) boiling and condensation; (2) water recovery; and (3) heat pipes.

microgravity↗
DOE OSTI2021

Increasing the Usability of Sockeye: Implementing Customer-Driven Modeling Improvements, Features, and Documentation of Sockeye

A number of tasks for the heat pipe simulation tool Sockeye were identified based on customer needs and included both user documentation and code development: (a) Implement saturation-dependence in the capillary pressure model; (b) Provide an analytic utility to analyze the frozen startup limit; (c) Demonstrate custom friction closures; (d) Develop examples for different types of heat transfer sources and boundary conditions; (e) Demonstrate the capillary and sonic limits; and (f) Provide discretization details in the theory manual. These tasks were all completed, and results are given where applicable.

97 MATHEMATICS AND COMPUTING↗
DOE OSTI2022

SPHERE Gas Composition Test and SOCKEYE Validation

The single primary heat extraction and removal emulator (SPHERE) gas composition test was performed to obtain data on the temperature distribution of a 2-m, 0.625-in.-diameter sodium-filled heat pipe from Advanced Cooling Technologies (ACT) in a horizontal orientation filled with varying gas compositions to support NEAMS tool development.

22 GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1987

Getter Capsules for Heat-Transport Systems

Metal absorbs hydrogen dissolved in heat-transfer fluids. Blockages by hydrogen gas in refrigerators, heat pipes, and other two-phase heat-transport systems eliminated by use of degassing metals or alloys called getters. Getter contained in getter capsule placed in series or in parallel with heat-transport loop. Gas-removal technique more specific and more reliable in solving problem of gas blockage than older procedures.

Seidenberg, Benjamin↗
NASA NTRSDate not supplied

Coupled Reactor Multiphysics and Mass Scalability Assessment for Crewed Megawatt-Class NEP System Architectures

Nuclear Electric Propulsion (NEP) is an in-space propulsion technology capable of enabling opposition and conjunction class crewed Mars missions. NEP subsystems include the reactor for heat generation, a power conversion system (PCS), power management and distribution, electric propulsion system, and heat rejection system. Specific mass, or α (kg/kWe), is a key performance parameter (KPP) of the propulsion system which is directly scalable with the performance and mass predictions for each individual component. To inform technology maturation planning activities, full system and component level parametric modeling is ongoing to explore the design trade space and illustrate the effect of subsystem design choices on the system KPPs. In this study, scaling of high-assay, low-enriched uranium reactor designs is assessed through coupled reactor physics and thermal hydraulics analyses. Scaling analyses evaluate the impact of system performance parameters (power level, interface temperatures) on mass for direct gas cooled, pumped liquid metal, and passively-cooled heat pipe reactor concepts. Each concept requires specific geometries, fluids, and power conversion interface conditions (temperature, pressure, flow rate) to meet desired performance and mass. The reactor assembly includes the active core (fuel, moderator, cladding, working fluid), axial and radial neutron reflectors, control drums, structural support / pressure vessel, and external radiation shielding. Each of these components are parametrically sized based on performance parameters for a megawatt-class power cycle. Results of this scaling analysis increase NEP propulsion system modeling fidelity and ultimately aim to support concept down-selection along with related technology development planning. The reactor and shield α are a function of several PCS and heat rejection system design choices, and reactor scaling with these parameters must be considered to enable an informed decision on an optimal reactor geometry and working fluid combination.

Nuclear Electric Propulsion↗
NASA NTRS2013

Alkali Metal Backup Cooling for Stirling Systems - Experimental Results

In a Stirling Radioisotope Power System (RPS), heat must be continuously removed from the General Purpose Heat Source (GPHS) modules to maintain the modules and surrounding insulation at acceptable temperatures. The Stirling convertor normally provides this cooling. If the Stirling convertor stops in the current system, the insulation is designed to spoil, preventing damage to the GPHS at the cost of an early termination of the mission. An alkali-metal Variable Conductance Heat Pipe (VCHP) can be used to passively allow multiple stops and restarts of the Stirling convertor. In a previous NASA SBIR Program, Advanced Cooling Technologies, Inc. (ACT) developed a series of sodium VCHPs as backup cooling systems for Stirling RPS. The operation of these VCHPs was demonstrated using Stirling heater head simulators and GPHS simulators. In the most recent effort, a sodium VCHP with a stainless steel envelope was designed, fabricated and tested at NASA Glenn Research Center (GRC) with a Stirling convertor for two concepts; one for the Advanced Stirling Radioisotope Generator (ASRG) back up cooling system and one for the Long-lived Venus Lander thermal management system. The VCHP is designed to activate and remove heat from the stopped convertor at a 19 degC temperature increase from the nominal vapor temperature. The 19 degC temperature increase from nominal is low enough to avoid risking standard ASRG operation and spoiling of the Multi-Layer Insulation (MLI). In addition, the same backup cooling system can be applied to the Stirling convertor used for the refrigeration system of the Long-lived Venus Lander. The VCHP will allow the refrigeration system to: 1) rest during transit at a lower temperature than nominal; 2) pre-cool the modules to an even lower temperature before the entry in Venus atmosphere; 3) work at nominal temperature on Venus surface; 4) briefly stop multiple times on the Venus surface to allow scientific measurements. This paper presents the experimental results from integrating the VCHP with an operating Stirling convertor and describes the methodology used to achieve their successful combined operation.

Stirling Convertor↗
NASA NTRS1942

Theory of Heat Transfer in Smooth and Rough Pipes

The heat transfer accompanying turbulent flow in tubes has been treated by a new theory of wall turbulence, and a formula for smooth tubes has been derived which is asymptotic at Re approaches infinity. It agrees very well with the data available to date. The formula also holds for the flow along a flat plate if lambda is based on the velocity far away. For rough tubes, the unit conductance is shown to be a function of kv*/upsilon; the two empirical constants (delta(r), n) which appear in equation (52) cannot yet be determined because of lack of experimental data.

Mattioli, G. D.↗
DOE OSTI2020

Modeling Efforts to Gain Insight into Historical Leak Events from the Single-Shell Tank A-105 in the Hanford 241-A Tank Farm - 20113

The 241-A Tank Farm is a single-shell tank (SST) farm constructed to store process waste from Hanford nuclear operations. Millions of gallons of nuclear waste were stored in the 241-A Tank Farm SSTs and some of the SSTs leaked in the past. In addition, spills and pipeline leaks during transfers and storage and intentional discharges to cribs and trenches resulted in releasing waste to the ground. Tank liner leaks are referred to as 'leaks' and all other discharges to the soil are referred to as 'releases.' Liquid waste that could be removed by pumping has been removed from all of the SSTs to reduce the potential for future leaks. The most significant historical leak event in 241-A Tank Farm occurred in 1965 when tank A-105 experienced a pressurized steam event. This event resulted in damage to the inner steel liner flooring of A-105, which was separated from the sidewalls over part of its circumference and buckled up to 2.5 m, vertically. During this event up to 7,570 L of contaminated liquid may have leaked to the adjacent soil. This leak occurred under extreme temperature and pressure conditions. Modeling efforts to better understand the nature and extent of historical leaks from subsurface SSTs that were used to store highly radioactive, self-boiling liquid wastes at 241-A Tank Farm have recently been undertaken. These efforts have compiled the available historical information to support a preliminary non-isothermal, multiphase flow and chemical transport modeling effort to re-create the conditions under which the leaks occurred and to formulate a conceptual model as to the extent and distribution of leaked radioactive contaminants in the adjacent soil material. The focus of this work was on developing an understanding of the key features, processes and bounding conditions related to tank A-105 leak events that occurred in the 1960's. The activities include estimation of leak composition, non-isothermal multiphase flow and transport modeling, and geochemical modeling. The STOMP{sup C} Water-Air-Energy modeling code was utilized to implement the three-dimensional representation of the subsurface tank and the surrounding flow field. Once constructed, the model was used to evaluate the conceptual understanding of leaks originating from different parts of the tank under the elevated temperature boundary conditions that were imposed by surrounding tanks at the time of the historical leaks. The chemical evolution of the liquid waste was also evaluated as it leaked from the tank under transient pressure and temperature gradients. The results of the preliminary evaluation suggested the presence of a heat-pipe effect beneath tank A-105 in which water vapor at an elevated temperature is driven away from the base of the tank to a position where water vapor cools, condenses and is then drawn back toward the tank by the strong capillary attraction of the dry soil. A non-sorbing contaminant (Tc-99) was introduced into this flow field to better understand the potential distribution patterns of leaked contaminants that may have occurred during the historical leak events. (authors)

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
NASA NTRS2014

ATLAS LTCS Vertically Challenged System Lessons Learned

Re-planning of LTCS TVAC testing and supporting RTA (Receiver Telescope Assembly) Test Plan and Procedure document preparation. The Laser Thermal Control System (LTCS) is designed to maintain the lasers onboard Advanced Topographic Laser Altimeter System (ATLAS) at their operational temperatures. In order to verify the functionality of the LTCS, a thermal balance test of the thermal hardware was performed. During the first cold start of the LTCS, the Loop Heat Pipe (LHP) was unable to control the laser mass simulators temperature. The control heaters were fully on and the loop temperature remained well below the desired setpoint. Thermal analysis of the loop did not show these results. This unpredicted behavior of the LTCS was brought up to a panel of LHP experts. Based on the testing and a review of all the data, there were multiple diagnostic performed in order to narrow down the cause. The prevailing theory is that gravity is causing oscillating flow within the loop, which artificially increased the control power needs. This resulted in a replan of the LTCS test flow and the addition of a GSE heater to allow vertical operation.

Loop Heat Pipe↗
NASA NTRSDate not supplied

Coupled Reactor Multiphysics and Mass Scalability Assessment for Crewed Megawatt-Class NEP System Architectures

Nuclear Electric Propulsion (NEP) is an in-space propulsion technology capable of enabling opposition and conjunction class crewed Mars missions. NEP subsystems include the reactor for heat generation, a power conversion system (PCS), power management and distribution (PMAD), electric propulsion subsystem (EPS), and a primary heat rejection system. Specific mass, or αe (kg / kWe), is a key performance parameter (KPP) of the propulsion system which is directly scalable with the performance and mass estimates for individual components. To inform technology maturation planning, full system and component level parametric modeling is ongoing to explore the design trade space and illustrate the effect of subsystem design choices on the system KPPs. In this study, scaling of high-assay, low-enriched uranium (HALEU) reactor designs is assessed through coupled reactor physics and thermal hydraulics analyses. Scaling analyses evaluate the impact of system performance parameters (power level, interface temperatures) on mass for direct gas cooled, pumped liquid metal, and passively cooled heat pipe reactor concepts. Each concept requires specific geometries and working fluids to reach the performance goals of PCS interface conditions (temperature, pressure, flow rate) and system mass. The reactor assembly includes the active core (fuel, moderator, cladding, working fluid), axial and radial neutron reflectors, control drums, structural support / pressure vessel, and external radiation shielding. Each of these components are parametrically sized based on performance parameters for a megawatt-class power cycle. Results of this scaling analysis increase NEP propulsion system modeling fidelity and ultimately aim to support technology down-selection along with related technology development planning. The reactor and shield αe are a function of several PCS design choices, and reactor scaling with these parameters must be considered to enable an informed decision on reactor geometry and working fluid combination.

Nuclear Electric Propulsion↗
NASA NTRS2014

LTCS (Laser Thermal Control System) Test Supporting the Improvement of DeCoM (Deepak Condenser Model)

Thermal and Fluids Analysis Workshop, Cleveland OH. NCTS 19701-14. On Dec 2013 a Loop Heat Pipe (LHP) test was performed as part of the integral Laser Thermal Control System (LTCS). During the balance portion of this testing it was noticed that the LHP was not going to be able to maintain temperature on the operational thermal mass. The test was stopped. After multiple meetings with the LTCS designers, LHP experts (in house and external) it was concluded that gravity was preventing the control heaters to maintain control on the reservoir. A heater was installed onto the liquid return line as part of the fix. After implementing the fix on the liquid return line, the test on May 2014 proved that the system works in vertical orientation using the liquid line heater. Through this testing, the correlation of the Deepak Condenser Model (DeCoM) was possible. This paper describes how well DeCoM predicts the condenser behavior in comparison to the test results of LTCS test.

0000↗
NASA NTRS1973

Thermal control system for a spacecraft modular housing

The development of a thermal control system for a spacecraft module is discussed. The wall structures are composed of superinsulation in some cases and of thermally conductive material in other cases. Heat pipes are installed to provide a path of heat transfer from the interior of the module to space. The design of the system makes it possible to maintain a relatively uniform temperature throughout the module with side variations of the amount of heat dissipated by the components within the module.

Eby, R. J.↗
NASA NTRS1986

Thermal-Diode Sandwich Panel

Thermal diode sandwich panel transfers heat in one direction, but when heat load reversed, switches off and acts as thermal insulator. Proposed to control temperature in spacecraft and in supersonic missiles to protect internal electronics. In combination with conventional heat pipes, used in solar panels and other heat-sensitive systems.

Basiulis, A.↗
NASA NTRS1989

Capillary-Condenser-Pumped Heat-Transfer Loop

Heat being transferred supplies operating power. Capillary-condenser-pumped heat-transfer loop similar to heat pipe and to capillary-evaporator-pumped heat-transfer loop in that heat-transfer fluid pumped by evaporation and condensation of fluid at heat source and sink, respectively. Capillary condenser pump combined with capillary evaporator pump to form heat exchanger circulating heat-transfer fluids in both loops. Transport of heat more nearly isothermal. Thermal stress in loop reduced, and less external surface area needed in condenser section for rejection of heat to heat sink.

Silverstein, Calvin C.↗