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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 289 records · Page 16
All sourcesNASA NTRSDOE OSTI
NASA NTRS2020

Psyche Magnetometer Engineering Model Test and Thermal Model Correlation to Validate Operational Thermal Requirement

Psyche Fluxgate Magnetometer candidate fabricated by UCLA has a critical temperature gradient requirement inside the magnetometer sensor head. Since the temperature gradient requirement is a driving factor for the magnetometer operation and science data collection at 16 Psyche, it is critical to validate and verify this requirement via modeling and test. In this work, a thermal vacuum test was completed for Psyche flight-like magnetometer engineering model. Flight-like environments were simulated for a hot operational case (after launch), a cold survival case (cruise), and two cold operational cases to characterize thermal performance of the instrument. An additional, non-flight, steady-state test case was completed to better correlate the magnetometer thermal model. During the test, sensitive Cernox temperature sensors with accuracy of ±0.1°C were used to precisely characterize the temperature gradient and correlate the model to the best accuracy. Collected test data indicated power consumption of 28% lower than predicted. The temperature gradient measured met the expected value and the requirement. Test data indicated the magnetometer also met the AFTs in relevant hot and cold environments. Test Results were used to correlate the thermal model. The correlated thermal model will be integrated to the spacecraft thermal model to predict magnetometer thermal performance while collecting science data in Psyche orbits.

Caron, Ryan↗
NASA NTRS2021

CubeSat Active Thermal Control in Support of Advanced Payloads: The Active Thermal Architecture Project

The Active Thermal Architecture (ATA) is an advanced sub-1U Active Thermal Control technology (ATC) for high power payload support in 6U CubeSat form factors and above. The design utilizes a two-stage, single-phase mechanically pumped fluid loop coupled through a two-axis flexible rotary fluid hinge, to reject thermal power to a deployable tracking radiator. A COTS Ricor K508N cryocooler forms the second stage and provides cryogenic cooling to a custom Kevlar detector mount through a TMT pyrolytic graphene thermal strap. Passive vibration isolation and damping technologies prevent the transfer of jitter to the satellite systems. The ATA design utilizes state-of-the-art 3D fabrication techniques such as Ultrasonic Additive Manufacturing (UAM) to directly embed the working fluid channels into the HX, radiator, and CubeSat chassis allowing for the miniaturization and simplification of the ATA system into an integrated thermal control solution. This paper will focus on the design and ground-based characterization and qualification of the ATA system and provide performance metrics for its use as a thermal support subsystem for advanced infrared electro-optical CubeSat payloads. The ATA project is funded through a NASA Small Satellite Technology Program (SSTP) and is a partnership between the Center for Space Engineering at Utah State University and the Jet Propulsions Laboratory. The ATA active thermal control system has been raised to a TRL of 6 and hopes to provide payload support to advanced missions such as the SABER-Lite and JPL CIRAS projects.

Mok, Mason↗
DOE OSTI2012

Methods of forming thermal management systems and thermal management methods

A thermal management system for a vehicle includes a heat exchanger having a thermal energy storage material provided therein, a first coolant loop thermally coupled to an electrochemical storage device located within the first coolant loop and to the heat exchanger, and a second coolant loop thermally coupled to the heat exchanger. The first and second coolant loops are configured to carry distinct thermal energy transfer media. The thermal management system also includes an interface configured to facilitate transfer of heat generated by an internal combustion engine to the heat exchanger via the second coolant loop in order to selectively deliver the heat to the electrochemical storage device. Thermal management methods are also provided.

25 ENERGY STORAGE↗
DOE OSTI2018

High thermal conductivity materials for thermal management applications

High thermal conductivity materials and methods of their use for thermal management applications are provided. In some embodiments, a device comprises a heat generating unit (304) and a thermally conductive unit (306, 308, 310) in thermal communication with the heat generating unit (304) for conducting heat generated by the heat generating unit (304) away from the heat generating unit (304), the thermally conductive unit (306, 308, 310) comprising a thermally conductive compound, alloy or composite thereof. The thermally conductive compound may include Boron Arsenide, Boron Antimonide, Germanium Carbide and Beryllium Selenide.

36 MATERIALS SCIENCE↗
DOE OSTI2023

Thermal Analysis of Thermal Shield for PIP-II SSR1 Cryomodule

Fermilab's PIP-II project plans to enhance the onsite accelerator into the world's most intense neutrino beam, bringing Fermilab into the next generation of particle accelerators. The five different types of cryomodules are vital parts of the PIP-II project and each requires numerous engineering analyses to prove operation. For example, the thermal shield of the Single Spoke Resonator-1 (SSR1) cryomodule required a thermal analysis to ensure the design was operating as intended before fabrication commenced. The thermal shield is cooled by the supercritical helium inside of the extrusion and must remain between 45 and 80 Kelvin. The main purpose of the thermal shield is to intercept different high heat loads and thermal radiation and prevent them from reaching the more sensitive internal components. Finite Element Analysis (FEM) was used to determine temperature estimates of the thermal shield based on the location of a variety of heat sources. Results determined temperatures exceeding the design limit around the crucial component of the current leads. Due to superconducting properties, the areas around the current leads cannot surpass 68 Kelvin. Different solutions to the critical high-temperature areas will be proposed. These solutions range from changing the properties of the helium flow to designing an attachment for the thermal shield. Each proposition works as a viable solution, however, each proposition also has its own set of advantages and disadvantages that are described for further design consideration.

43 PARTICLE ACCELERATORS↗
DOE OSTI2024

Systems and methods for thermal barrier coatings to modify engine component thermal characteristics

An engine component comprises one or more thermal barrier coatings applied to one or more areas of the engine component. The thermal barrier coatings reduce the temperature rate of change of the areas to which the thermal barrier coating is applied. Reducing the temperature rate of change can help reduce lattice structure damage caused by different temperatures in different areas of the engine component. The thermal barrier coating can be applied as a monolithic layer on a surface of the engine component or can be applied in different areas using patterns. The patterns allow for the tuning of the performance characteristics (temperature rate of change) of the areas of the engine component and can help reduce defect propagation, such as cracks, in the thermal barrier coating from one area of the thermal barrier coating to other areas of the thermal barrier coating.

Koci, Chad Palmer↗
DOE OSTI2013

An International Round-Robin Study, Part II: Thermal Diffusivity, Specific Heat and Thermal Conductivity

For bulk thermoelectrics, figure-of-merit, ZT, still needs to improve from the current value of 1.0 - 1.5 to above 2 to be competitive to other alternative technologies. In recent years, the most significant improvements in ZT were mainly due to successful reduction of thermal conductivity. However, thermal conductivity cannot be measured directly at high temperatures. The combined measurements of thermal diffusivity and specific heat and density are required. It has been shown that thermal conductivity is the property with the greatest uncertainty and has a direct influence on the accuracy of the figure of merit. The International Energy Agency (IEA) group under the implementing agreement for Advanced Materials for Transportation (AMT) has conducted two international round-robins since 2009. This paper is Part II of the international round-robin testing of transport properties of bulk bismuth telluride. The main focuses in Part II are on thermal diffusivity, specific heat and thermal conductivity.

specific heat↗
DOE OSTI2017

Thermophysical Properties of Cold- and Vacuum Plasma-Sprayed Cu-Cr-X Alloys, NiAl and NiCrAlY Coatings I: Electrical and Thermal Conductivity, Thermal Diffusivity, and Total Hemispherical Emissivity

This two-part paper reports the thermophysical properties of several cold- and vacuum plasma-sprayed monolithic Cu- and Ni-based alloy coatings. Part I presents the electrical and thermal conductivity, thermal diffusivity, and total hemispherical emissivity data, while Part II reports the specific heat capacity data for these coatings. Metallic copper alloys and stoichiometric NiAl and NiCrAlY coatings were fabricated by either the cold spray or the vacuum plasma spray deposition processes for thermal property measurements between 77 and 1223 K. The temperature dependencies of the thermal conductivities, thermal diffusivities, electrical conductivities, and total hemispherical emissivities of these cold- and vacuum-sprayed monolithic coatings are reported in this paper. The electrical and thermal conductivity data correlate reasonably well for Cu-8%Cr-1%Al, Cu-23%Cr-5%Al, and NiAl in accordance with the Wiedemann–Franz (WF) law although a better fit is obtained using the Smith–Palmer relationship. The Lorentz numbers determined from the WF law are close to the theoretical value.

36 MATERIALS SCIENCE↗
DOE OSTI2016

Thermal energy storage to minimize cost and improve efficiency of a polygeneration district energy system in a real-time electricity market

District energy systems can produce low-cost utilities for large energy networks, but can also be a resource for the electric grid by their ability to ramp production or to store thermal energy by responding to real-time market signals. In this work, dynamic optimization exploits the flexibility of thermal energy storage by determining optimal times to store and extract excess energy. This concept is applied to a polygeneration distributed energy system with combined heat and power, district heating, district cooling, and chilled water thermal energy storage. The system is a university campus responsible for meeting the energy needs of tens of thousands of people. The objective for the dynamic optimization problem is to minimize cost over a 24-h period while meeting multiple loads in real time. The paper presents a novel algorithm to solve this dynamic optimization problem with energy storage by decomposing the problem into multiple static mixed-integer nonlinear programming (MINLP) problems. Another innovative feature of this work is the study of a large, complex energy network which includes the interrelations of a wide variety of energy technologies. Results indicate that a cost savings of 16.5% is realized when the system can participate in the wholesale electricity market.

25 ENERGY STORAGE↗
DOE OSTI2020

Porous architecture and thermal properties of thermal barrier coatings deposited by suspension plasma spray

Besides the intrinsic low heat transfer capability of material, the thermal insulation property of thermal barrier coatings (TBCs) also relies on their microstructures. For better understanding the relationship between process parameters, porous architecture, and thermal properties of coatings, YSZ coatings were firstly manufactured by suspension plasma spray (SPS). Afterwards their total porosities were characterized by using the technique of X-ray transmission, the nano/submicro pores in those coatings were detected with Ultra-Small Angle X-ray Scattering (USAXS), and the thermal properties of coatings were measured using the laser flash method. The results indicated that: i) the porous architecture of SPS coatings can be tailored by adapting process parameters. ii) increasing total porosity is an effective means for reducing the heat transfer capability of SPS coatings. iii) nano/submicro pores have higher influence sensitivity on thermal properties than that of larger pores. Increasing the content of nano-submicro pores is therefore more effective for improving the thermal insulation property of SPS coatings. The potential of SPS technique for fabricating TBCs was discussed as well.

36 MATERIALS SCIENCE↗
DOE OSTI2017

Facet-Dependent Thermal Instability in LiCoO2

Thermal runaways triggered by the oxygen release from oxide cathode materials pose a major safety concern for widespread application of lithium ion batteries. Utilizing in situ aberration-corrected scanning transmission electron microscopy (STEM) and electron energy loss spectroscopy (EELS) at high temperatures, we show that oxygen release from LixCoO2 cathode crystals is occurring at the surface of particles. We correlated this local oxygen evolution from the LixCoO2 structure with local phase transitions spanning from layered to spinel and then to rock salt structure upon exposure to elevated temperatures. Ab initio molecular dynamics simulations (AIMD) results show that oxygen release is highly dependent on LixCoO2 facet orientation. While the [001] facets are stable at 300 degrees C, oxygen release is observed from the [012] and [104] facets, where under-coordinated oxygen atoms from the delithiated structures can combine and eventually evolve as O-2. The novel understanding that emerges from the present study piovides in-depth insights into the thermal runaway mechanism of Li-ion batteries and can assist the design and fabrication of cathode crystals with the most thermally stable facets.

ab initio molecular dynamics↗
DOE OSTI2026

Suppressing thermal transport in nonporous polymer hybrids by limiting thermally accessible vibrational modes

Achieving low thermal conductivity in nonporous polymer materials without compromising mechanical integrity remains a longstanding challenge. Conventional strategies, such as introducing porosity, are inherently limited in dense systems. Here, in this study, we demonstrate that thermal transport in polymer–organic filler hybrids is closely associated with the engineered availability of thermally accessible vibrational modes, rather than individual interfacial resistance or porosity. Using PU/organic filler hybrids as a model system, we show that incorporating rigid organic motifs shifts the vibrational density of states toward higher frequencies, where vibrational modes are weakly thermally populated at ambient conditions. This limits the number of heat-carrying channels, leading to suppressed thermal conductivity despite negligible individual interfacial resistance (∼10 −9 m 2 K W −1 ). These findings provide initial evidence that vibrational mode engineering may offer a promising molecular-level route for reducing thermal conductivity in dense polymer–organic hybrid systems.

36 MATERIALS SCIENCE↗
DOE OSTI2015

Behavior of nanoporous thermal barrier coatings under cyclic thermal loading. Computer-aided simulation

The work presents the development of new algorithms for calculating the fraction of thermal energy dissipated during the irradiation on the inner surface of pores. On the basis of these algorithms, the simulation of heat transfer in three-layered systems was carried out taking into account the dissipation of thermal energy in specimens having different porosity. We have performed quantitative estimates of the portion of dissipating thermal energy and its influence on the distribution of thermal stresses in thermal barrier coating systems. It was demonstrated that the presence of pores with a large internal surface area in the intermediate layer material enables two-fold decrease of the internal thermal stresses.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2015

Non-thermal production of minimal dark matter via right-handed neutrino decay

Minimal Dark Matter (MDM) stands as one of the simplest dark matter scenarios. In MDM models, annihilation and co-annihilation processes among the members of the MDM multiplet are usually very efficient, pushing the dark matter mass above O(10) TeV in order to reproduce the observed dark matter relic density. Motivated by this little drawback, in this paper we consider an extension of the MDM scenario by three right-handed neutrinos. Two specific choices for the MDM multiplet are studied: a fermionic SU(2){sub L} quintuplet and a scalar SU(2){sub L} septuplet. The lightest right-handed neutrino, with tiny Yukawa couplings, never reaches thermal equilibrium in the early universe and is produced by freeze-in. This creates a link between dark matter and neutrino physics: dark matter can be non-thermally produced by the decay of the lightest right-handed neutrino after freeze-out, allowing to lower significantly the dark matter mass. We discuss the phenomenology of the non-thermally produced MDM and, taking into account significant Sommerfeld corrections, we find that the dark matter mass must have some specific values in order not to be in conflict with the current bounds from gamma-ray observations.

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS↗
DOE OSTI2019

Thermal and Thermomechanical Modeling to Design a Gallium Oxide Power Electronics Package: Preprint

The power electronics industry is currently undergoing a major transition by replacing silicon devices with wide-bandgap devices. Gallium oxide devices have the potential to accelerate this transition by offering comparable or even superior performance to other wide-bandgap devices, but at a much lower cost. Recent breakthroughs include demonstration of a laboratory-scale gallium oxide transistors and diodes; however, a functional power electronics package for these devices is yet to be developed. In this paper, the research methodology in designing an electronics package for gallium oxide devices is outlined. Finite element-based thermal and thermomechanical modeling simulations were conducted to realize a package design that meets the combined target of minimal thermal resistance and improved reliability. Different package designs that include various material combinations and cooling configurations were explored, and their thermal and thermomechanical performance are reported. Furthermore, the short-circuit withstanding capabilities of gallium oxide devices were studied and compared with silicon carbide.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2020

Thermal Properties of Sodium Borosilicate Glasses as a Function of Sulfur Content

SO3 additions, up to 3.0 wt%, were systematically investigated for effects on the physical properties of sodium borosilicate glass melted in air, with a sulfur-free composition of 50SiO2-10Al2O3-12B2O3-21Na2O-7CaO (wt%). Solubility measurements, using electron microscopy chemical analysis, determined the maximum loading to be ~1.5 wt% SO3. It was found that sulfur (here as sulfate) in this glass increased the glass transition temperature, thermal diffusivity, heat capacity, and thermal conductivity, and decreased the mass density. Structural analysis, performed with Raman spectroscopy, indicated that the borosilicate network polymerized with sulfur additions, presumably due to Na2O being required to charge compensate the ionic SO42- additions, thus becoming unavailable to form non-bridging oxygen in the silicate network. It is postulated that this increased crosslinking of the borosilicate backbone lead to a structure with higher dimensionality and average bond energy. This increased the mean free paths and vibration frequency of the phonons, which resulted in the observed increase in thermal properties.

Thermal properties, Borosilicate glass, Sulfur sol↗
NASA NTRS2004

A comparative analysis of loop heat pipe based thermal architectures for spacecraft thermal control

Loop Heat Pipes (LHP) have gained acceptance as a viable means of heat transport in many spacecraft in recent years. However, applications using LHP technology tend to only remove waste heat from a single component to an external radiator. Removing heat from multiple components has been done by using multiple LHPs. This paper discusses the development and implementation of a Loop Heat Pipe based thermal architecture for spacecraft. In this architecture, a Loop Heat Pipe with multiple evaporators and condensers is described in which heat load sharing and thermal control of multiple components can be achieved. A key element in using a LHP thermal architecture is defining the need for such an architecture early in the spacecraft design process. This paper describes an example in which a LHP based thermal architecture can be used and how such a system can have advantages in weight, cost and reliability over other kinds of distributed thermal control systems. The example used in this paper focuses on a Mars Rover Thermal Architecture. However, the principles described here are applicable to Earth orbiting spacecraft as well.

loop heat pipes↗
NASA NTRS2015

Solar Probe Plus MAG Sensor Thermal Design for Low Heater Power and Extreme Thermal Environment

The heater power available for the Solar Probe Plus FIELDS MAG sensor is less than half of the heritage value for other missions. Nominally the MAG sensors are in the spacecraft's umbra. In the worst hot case, approximately 200 spacecraft communication downlinks, up to 10 hours each, are required at 0.7 AU. These downlinks require the spacecraft to slew 45 deg. about the Y-axis, exposing the MAG sensors and boom to sunlight. This paper presents the thermal design to meet the MAG sensor thermal requirements in the extreme thermal environment and with low heater power. A thermal balance test on the MAG sensor engineering model has verified the thermal design and correlated the thermal model for flight temperature predictions.

Thermal design↗