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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 559 records · Page 31
All sourcesNASA NTRSDOE OSTI
NASA NTRS1986

Prototype thermal bus for manned Space Station compartments

A summary is presented of NASA efforts, to February 1986, on development of an advanced thermal bus for manned spacecraft. Design details are described for a prototype to be tested in 1987 that includes a contact heat exchanger, an air cooling heat exchanger for manned cabin conditions, and an interface heat exchanger for transferring compartment heat loads to the Space Station Central Thermal Bus. The design and performance criteria defined for the thermal bus are outlined and results are reported from comparisons of the capabilities and operational costs of pumped water and two-phase evaporating/condensing heat transport concepts. The operating temperature, launch weight/thermal performance ratios, and power requirements of each concept are discussed, along with the critical technologies identified for use of a water/titanium two-phase thermal bus.

Zentner, Ronald C.↗
NASA NTRS1989

Superfluid helium orbital resupply - The status of the SHOOT flight experiment and preliminary user requirements

The Superfluid Helium On-Orbit Transfer (SHOOT) flight experiment is designed to demonstrate the components and techniques necessary to resupply superfluid helium to satellites or Space Station based facilities. A top level description as well as the development status of the critical components to be used in SHOOT are discussed. Some of these components include the thermomechanical pump, the fluid acquisition system, the normal helium and superfluid helium phase separators, Venturi flow meter, cryogenic valves, burst disks, and astronaut-compatible EVA coupler and transfer line. The requirements for the control electronics and software are given. A preliminary description of the requirements that must be met by a satellite requiring superfluid helium servicing is given. In particular, minimum and optimum plumbing arrangements are shown, transfer line flow impedance and heat input impacts are assessed, instrumentation is described, and performance parameters are considered.

Dipirro, Michael J.↗
NASA NTRS1990

Computation of turbine flowfields with a Navier-Stokes code

A new technique has been developed for the solution of the incompressible Navier-Stokes equations. The numerical technique, derived from a pressure substitution method (PSM), overcomes many of the deficiencies of the pressure crrection method. This technique allows for the direct solution of the actual pressure in the form of a Poisson equation which is derived from the pressure weighted substitution of the full momentum equations into the continuity equation. In two-dimensions a turbine flowfield, including heat transfer, has been computed with this method and the prediction of the cascade performance is presented. The extension of the pressure correction method for the solution of three-dimensional flows is also presented for laminar flow in an S-shaped duct and turbulent flow in the end-wall region of a turbine cascade.

Hobson, G. V.↗
NASA NTRS1994

Analyzing Thermal Conditions In Rocket Engines

Computer code, RTE, developed to perform three-dimensional thermal analyses of rocket thrust chambers. Calculates rate of heat transfer from combustion gases to coolant, coolant-temperature rise and pressure drop, and temperature profiles within cooling-jacket wall. Also calculates combustion-gas wall static pressure, temperature and enthalpy, as well as coolant pressure, temperature, and mach number for all stations. Program used for any propellant combination and most coolants commonly used in rockets. Code used for both regeneratively and radiatively cooled engines. However, in case of regeneratively cooled engines, applicability limited to engines featuring single-pass cooling and rectangular cooling channels.

Naraghi, M. H. N.↗
NASA NTRS1993

The formation process of the He I lambda 10830 line in cool giant stars

The Final Report on the formation process of the He I lambda 10830 line in cool giant stars is presented. The research involves observing a sample of cool giant stars with ROSAT. These stars were selected from the list of bright stars which display He I lambda 10830 in absorption or emission and lie on the cool side of the coronal dividing line. With measured x ray fluxes or upper limits measured by the Position Sensitive Proportional Counter (PSPC), the role x rays play in the formation of this important line was investigated using the non-LTE radiative transfer code PANDORA. Hydrodynamic calculations were performed to investigate the contributions of acoustic wave heating in the formation of this line as well.

Luttermoser, Donald G.↗
NASA NTRS2006

Conjugate Heat Transfer Analyses on the Manifold for Ramjet Fuel Injectors

Three-dimensional conjugate heat transfer analyses on the manifold located upstream of the ramjet fuel injector are performed using CFdesign, a finite-element computational fluid dynamics (CFD) software. The flow field of the hot fuel (JP-7) flowing through the manifold is simulated and the wall temperature of the manifold is computed. The three-dimensional numerical results of the fuel temperature are compared with those obtained using a one-dimensional analysis based on empirical equations, and they showed a good agreement. The numerical results revealed that it takes around 30 to 40 sec to reach the equilibrium where the fuel temperature has dropped about 3 F from the inlet to the exit of the manifold.

Wang, Xiao-Yen J.↗
NASA NTRS1991

Hydride heat pump with heat regenerator

A regenerative hydride heat pump process and system is provided which can regenerate a high percentage of the sensible heat of the system. A series of at least four canisters containing a lower temperature performing hydride and a series of at least four canisters containing a higher temperature performing hydride is provided. Each canister contains a heat conductive passageway through which a heat transfer fluid is circulated so that sensible heat is regenerated. The process and system are useful for air conditioning rooms, providing room heat in the winter or for hot water heating throughout the year, and, in general, for pumping heat from a lower temperature to a higher temperature.

Jones, Jack A.↗
NASA NTRS2014

Spring 2014 Internship Diffuser Data Analysis

J-2X engine testing on the A-2 test stand at the NASA John C. Stennis Space Center (SSC) has recently concluded. As part of that test campaign, the engine was operated at lower power levels in support of expanding the use of J-2X to other missions. However, the A-2 diffuser was not designed for engine testing at the proposed low power levels. To evaluate the risk of damage to the diffuser, computer simulations were created of the rocket engine exhaust plume inside the 50ft long, water-cooled, altitude-simulating diffuser. The simulations predicted that low power level testing would cause the plume to oscillate in the lower sections of the diffuser. This can possibly cause excessive vibrations, stress, and heat transfer from the plume to the diffuser walls. To understand and assess the performance of the diffuser during low power level engine testing, nine accelerometers and four strain gages were installed around the outer surface of the diffuser. The added instrumentation also allowed for the verification of the rocket exhaust plume computational model. Prior to engine hot-fire testing, a diffuser water-flow test was conducted to verify the proper operation of the newly installed instrumentation. Subsequently, two J-2X engine hot-fire tests were completed. Hot-Fire Test 1 was 11.5 seconds in duration, and accelerometer and strain data verified that the rocket engine plume oscillated in the lower sections of the diffuser. The accelerometers showed very different results dependent upon location. The diffuser consists of four sections, with Section 1 being closest to the engine nozzle and Section 4 being farthest from the engine nozzle. Section 1 accelerometers showed increased amplitudes at startup and shutdown, but low amplitudes while the diffuser was started. Section 3 accelerometers showed the opposite results with near zero G amplitudes prior to and after diffuser start and peak amplitudes to +/- 100G while the diffuser was started. Hot-Fire Test 1 strain gages showed different data dependent on section. Section 1 strains were small, and were in the range of 50 to 150 microstrain, which would result in stresses from 1.45 to 4.35 ksi. The yield stress of the material, A-285 Grade C Steel, is 29.7 ksi. Section 4 strain gages showed much higher values with strains peaking at 1600 microstrain. This strain corresponds to a stress of 46.41 ksi, which is in excess of the yield stress, but below the ultimate stress of 55 to 75 ksi. The decreased accelerations and strain in Section 1, and the increased accelerations and strain in Sections 3 and 4 verified the computer simulation prediction of increased plume oscillations in the lower sections of the diffuser. Hot-Fire Test 2 ran for a duration of 125 seconds. The engine operated at a slightly higher power level than Hot-Fire Test 1 for the initial 35 seconds of the test. After 35 seconds the power level was lowered to Hot-Fire Test 1 levels. The acceleration and strain data for Hot-Fire Test 2 was similar during the initial part of the test. However, just prior to the engine being lowered to the Hot-Fire Test 1 power level, the strain gage data in Section 4 showed a large decrease to strains near zero microstrain from their peak at 1500 microstrain. Future work includes further strain and acceleration data analysis and evaluation.

Laigaie, Robert T.↗
NASA NTRS2011

Development of an Extreme High Temperature n-type Ohmic Contact to Silicon Carbide

We report on the initial demonstration of a tungsten-nickel (75:25 at. %) ohmic contact to silicon carbide (SiC) that performed for up to fifteen hours of heat treatment in argon at 1000 C. The transfer length method (TLM) test structure was used to evaluate the contacts. Samples showed consistent ohmic behavior with specific contact resistance values averaging 5 x 10-4 -cm2. The development of this contact metallization should allow silicon carbide devices to operate more reliably at the present maximum operating temperature of 600 C while potentially extending operations to 1000 C. Introduction Silicon Carbide (SiC) is widely recognized as one of the materials of choice for high temperature, harsh environment sensors and electronics due to its ability to survive and continue normal operation in such environments [1]. Sensors and electronics in SiC have been developed that are capable of operating at temperatures of 600 oC. However operating these devices at the upper reliability temperature threshold increases the potential for early degradation. Therefore, it is important to raise the reliability temperature ceiling higher, which would assure increased device reliability when operated at nominal temperature. There are also instances that require devices to operate and survive for prolonged periods of time above 600 oC [2, 3]. This is specifically needed in the area of hypersonic flight where robust sensors are needed to monitor vehicle performance at temperature greater than 1000 C, as well as for use in the thermomechanical characterization of high temperature materials (e.g. ceramic matrix composites). While SiC alone can withstand these temperatures, a major challenge is to develop reliable electrical contacts to the device itself in order to facilitate signal extraction

Evans, Laura J.↗
NASA NTRSDate not supplied

Experimental, Computational, Theoretical and Analytical Investigation of Flow Boiling in Reduced Gravity

Two-phase thermal management systems are far superior to their single-phase counterparts because of their ability to capitalize on the coolant’s both sensible and latent heats, thereby yielding orders of magnitude higher heat transfer coefficients and smaller system footprints. A vital knowledge necessary for their implementation in future space systems is performance in microgravity. Long-duration microgravity experiments are necessary to obtain reliable databases, which would then be used to build reliable predictive tools. To achieve this goal, investigators at the Purdue University Boiling and Two-Phase Flow Laboratory (PU-BTPFL) and the NASA Glenn Research Center (NASA-GRC) have been collaborating towards the development of the Flow Boiling and Condensation Experiment (FBCE) and eventual execution onboard the International Space Station (ISS). FBCE has now matured to a point where it is ready for transport to the ISS, where first tests will be conducted using the Flow Boiling Module (FBM). In preparation for the ISS tests, a series of pre-launch Mission Sequence Tests (MSTs) was performed at GRC in Earth gravity with FBM mounted in a vertical upflow orientation using n-perfluorohexane as working fluid. The pre-launch tests included variations of flow rate, surface heat flux, inlet conditions, and both single-sided and double-sided wall heating. This presentation will summarize experimental results from these tests as well as both analytic and theoretical tools for prediction of two-phase heat transfer coefficient and critical heat flux (CHF). Also discussed will be an assessment of predictive accuracy of these tools against the experimental data.

Mission Sequence tests↗
NASA NTRSDate not supplied

Radiative Heat Transfer Capability Implemented in OpenNCC for Conjugate Heat Transfer Applications

Thermal efficiency of gas turbine engine increases as the temperature and pressure at the combustor increases. Consequently, the materials used inside a combustor must survive an increasingly challenging environment. For this reason, accurate assessment of heat transfer is crucial for combustor design. While all three modes of heat transfer are present inside a combustor, the focus of this paper is the thermal radiation. Radiative heat transfer in a gas turbine combustors are particularly interesting from three reasons. Firstly, the radiative heat loss from the combustion region may affect the emission performance. Secondly, the cooling air will protect the liner from convection but not necessary from radiation. Finally, it is less frequently incorporated in CFD analysis than other forms of heat transfer. In this work, radiative heat transfer using discrete ordinate method has been incorporated in OpenNCC (a publicly releasable version of the National Combustion Code) developed at NASA Glenn Research Center. Aside from massively parallel computation capability using MPI and the ability to utilize unstructured mesh, the current implementation includes two types of spectral models, namely, the weighted some of gray gas model and the full spectrum correlated k-distribution model. After presenting the theory and the strategy of implementation, results of validation cases for gray gas and spectral models will be presented. While the implementation of the radiation solver is intended for gas turbine application, the radiation solver can run independently from the convection/combustion solver and the same theory can be applied to other application.

OpenNCC↗
NASA NTRSDate not supplied

Radiative Heat Transfer Capability Implemented in OpenNCC for Conjugate Heat Transfer Applications

Thermal efficiency of gas turbine engine increases as the temperature and pressure at the combustor increases. Consequently, the materials used inside a combustor must survive an increasingly challenging environment. For this reason, accurate assessment of heat transfer is crucial for combustor design. While all three modes of heat transfer are present inside a combustor, the focus of this paper is the thermal radiation. Radiative heat transfer in a gas turbine combustors are particularly interesting from three reasons. Firstly, the radiative heat loss from the combustion region may affect the emission performance. Secondly, the cooling air will protect the liner from convection but not necessary from radiation. Finally, it is less frequently incorporated in CFD analysis than other forms of heat transfer. In this work, radiative heat transfer using discrete ordinate method has been incorporated in OpenNCC (a publicly releasable version of the National Combustion Code) developed at NASA Glenn Research Center. Aside from massively parallel computation capability using MPI and the ability to utilize unstructured mesh, the current implementation includes two types of spectral models, namely, the weighted some of gray gas model and the full spectrum correlated k-distribution model. After presenting the theory and the strategy of implementation, results of validation cases for gray gas and spectral models will be presented. While the implementation of the radiation solver is intended for gas turbine application, the radiation solver can run independently from the convection/combustion solver and the same theory can be applied to other application.

OpenNCC↗
NASA NTRS1994

Oscillating-flow regenerator test rig

This report summarizes work performed in setting up and performing tests on a regenerator test rig. An earlier status report presented test results, together with heat transfer correlations, for four regenerator samples (two woven screen samples and two felt metal samples). Lessons learned from this testing led to improvements to the experimental setup, mainly instrumentation as well as to the test procedure. Given funding and time constraints for this project it was decided to complete as much testing as possible while the rig was set up and operational, and to forego final data reduction and analysis until later. Additional testing was performed on several of the previously tested samples as well an on five newly fabricated samples. The following report is a summary of the work performed at OU, with many of the final test results included in raw data form.

Wood, J. G.↗
NASA NTRS1991

Numerical prediction of turbulent oscillating flow and associated heat transfer

A crucial point for further development of engines is the optimization of its heat exchangers which operate under oscillatory flow conditions. It has been found that the most important thermodynamic uncertainties in the Stirling engine designs for space power are in the heat transfer between gas and metal in all engine components and in the pressure drop across the heat exchanger components. So far, performance codes cannot predict the power output of a Stirling engine reasonably enough if used for a wide variety of engines. Thus, there is a strong need for better performance codes. However, a performance code is not concerned with the details of the flow. This information must be provided externally. While analytical relationships exist for laminar oscillating flow, there has been hardly any information about transitional and turbulent oscillating flow, which could be introduced into the performance codes. In 1986, a survey by Seume and Simon revealed that most Stirling engine heat exchangers operate in the transitional and turbulent regime. Consequently, research has since focused on the unresolved issue of transitional and turbulent oscillating flow and heat transfer. Since 1988, the University of Minnesota oscillating flow facility has obtained experimental data about transitional and turbulent oscillating flow. However, since the experiments in this field are extremely difficult, lengthy, and expensive, it is advantageous to numerically simulate the flow and heat transfer accurately from first principles. Work done at the University of Minnesota on the development of such a numerical simulation is summarized.

Koehler, W. J.↗
NASA NTRSDate not supplied

Flow Boiling and Condensation Experiment (FBCE): Summary of Findings for Flow Boiling based on Completed ISS Experiments

Since 2011, researchers from Purdue University and NASA Glenn Research Center (GRC) have been collaborating to investigate the effects of gravity on several aspects of flow boiling and flow condensation. This massive research endeavor, termed the Flow Boiling and Condensation Experiment (FBCE), has culminated in development of NASA’s largest and most complex facility for investigation of two-phase fluid physics onboard the ISS. FBCE consists of two separate studies: flow boiling, using the Flow Boiling Module (FBM), and flow condensation, using the Condensation Module for Heat Transfer Measurements (CM-HT); this presentation concerns the FBM portion of FBCE. Fitted with FBM, FBCE was launched to the ISS in August 2021 and experiments were successfully performed starting in February 2022 to amass a large microgravity-flow-boiling database supported by extensive visualization of interfacial behavior using high-speed video. Based on FBCE experiments performed previously in Earth gravity and parabolic flight, along with the new ISS data, several empirical correlations, theoretical models, and CFD models have been developed, enabling the prediction of crucial flow boiling parameters, including heat transfer coefficient and critical heat flux (CHF). These predictive tools, which will be summarized in this presentation, are expected to serve as foundation for design of future space systems involving flow boiling.

Two-phase flow and phase transition↗
NASA NTRS1993

Performance of thermal adhesives in forced convection

Cooling is critical for the life and performance of electronic equipment. In most cases cooling may be achieved by natural convection but forced convection may be necessary for high wattage applications. Use of conventional type heat sinks may not be feasible from the viewpoint of specific applications and the costs involved. In a heat sink, fins can be attached to the well by ultrasonic welding, by soldering, or with a number of industrially available thermal adhesives. In this paper, the author investigates the heat transfer characteristics of several adhesives and compares them with ultrasonic welding and theoretically calculated values. This experiment was conducted in an air flow chamber. Heat was generated by using heaters mounted on the well. Thermstrate foil, Uniset A401, and Aremco 571 adhesives were tested along with an ultrasonically welded sample. Ultrasonic welding performed far better than the adhesives and Thermstrate foil. This type of experiment can be adapted for a laboratory exercise in an upper level heat transfer course. It gives students an exposure to industrial applications that help them appreciate the importance of the course material.

Kundu, Nikhil K.↗
NASA NTRS1980

TAP 2: A finite element program for thermal analysis of convectively cooled structures

A finite element computer program (TAP 2) for steady-state and transient thermal analyses of convectively cooled structures is presented. The program has a finite element library of six elements: two conduction/convection elements to model heat transfer in a solid, two convection elements to model heat transfer in a fluid, and two integrated conduction/convection elements to represent combined heat transfer in tubular and plate/fin fluid passages. Nonlinear thermal analysis due to temperature-dependent thermal parameters is performed using the Newton-Raphson iteration method. Transient analyses are performed using an implicit Crank-Nicolson time integration scheme with consistent or lumped capacitance matrices as an option. Program output includes nodal temperatures and element heat fluxes. Pressure drops in fluid passages may be computed as an option. User instructions and sample problems are presented in appendixes.

Thornton, E. A.↗
NASA NTRSDate not supplied

Flow Boiling and Condensation Experiment (FBCE): From Initial Concept to Full Implementation on the International Space Station

Two phase thermal management systems that capitalize on both latent and sensible heats of the working fluid can yield orders of magnitude enhancements in flow boiling and condensation heat transfer coefficients and reduce size and weight of future space systems. Because the understanding of microgravity influences on two-phase flow and heat transfer is quite limited, there is presently an urgent need for a new experimental microgravity facility to enable investigators to perform long-duration flow boiling and condensation experiments in pursuit of reliable databases. This presentation will discuss evolution of the Flow Boiling and Condensation Experiment (FBCE), a collaborative effort between Purdue University and NASA Glenn Research Center, from initial concept with clearly defined objectives to full implementation on the International Space Station (ISS). It will be shown how this facility will serve as a primary platform for obtaining two-phase flow and heat transfer data in microgravity. By comparing the microgravity data against those obtained in Earth gravity, it will be possible to ascertain the influence of body force on two-phase transport phenomena in pursuit of mechanistic models as well as correlations, and to help determine the minimum flow criteria to ensure gravity independent flow boiling and condensation.

Flow boiling↗