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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 145 records · Page 8
All sourcesNASA NTRSDOE OSTI
DOE OSTI2011

Thermoelectric and Structural Properties of High-Performance In-based Skutterudites for High-Temperature Energy Recovery

The temperature-dependent thermoelectric and structural properties of n-type filled skutterudites were measured from 300 K to about 650 K. In0.2Co4Sb12, and In0.2Ce0.05Yb0.1Co4Sb12 exhibited ZT values as high as 1.2 at 620 K and In0.2Ce0.15Co4Sb12 showed ZT values of ~1.4 at 675 K. The room temperature Young’s modulus, Poisson’s ratio and coefficient of thermal expansion (CTE at 473 K) of In0.2Ce0.15Co4Sb12, In0.2Co4Sb12, and In0.2Ce0.05Yb0.1Co4Sb12 compositions were found to be lower than that for the unfilled Co4Sb12 skutterudite material. It was discovered that thermal cycling of n-type In0.15Ce0.1Co4Sb12 and In0.2Ce0.17Co4Sb12 materials from 323 K to 673 K (200 cycles) actually increased their power factors by 14-36% at 510 K to 525 K without appreciably changing the Young’s modulus or the Poisson’s ratio. The transport and structural properties characterized in this work are critical to transitioning these materials into operating TE devices and systems.

High-Temperature Energy Recovery↗
DOE OSTI2011

Material and energy recovery in integrated waste management system - An Italian case study on the quality of MSW data

This paper analyses the way numerical data on Municipal Solid Waste (MSW) quantities are recorded, processed and then reported for six of the most meaningful Italian Districts and shows the difficulties found during the comparison of these Districts, starting from the lack of homogeneity and the fragmentation of the data indispensable to make this critical analysis. These aspects are often ignored, but data certainty are the basis for serious MSW planning. In particular, the paper focuses on overall Source Separation Level (SSL) definition and on the influence that Special Waste (SW) assimilated to MSW has on it. An investigation was then necessary to identify new parameters in place of overall SSL. Moreover, these parameters are not only important for a waste management system performance measure, but are fundamental in order to design and check management plan and to identify possible actions to improve it.

12 MANAGEMENT OF RADIOACTIVE AND NON-RADIOACTIVE W↗
DOE OSTI2021

Pressure Exchanger for Energy Recovery in a Trans-Critical CO2 Refrigeration System

Trans-critical CO2 vapor compression (VC) refrigeration cycles require a high compression ratio, which is associated with high expansion losses. To recover these expansion losses, a pressure exchange process between the low- and high-pressure sides of the VC cycle is proposed and examined in this study. The proposed pressure exchange system is an open type constant volume process where the high- and low-pressure flows mix inside the system. This prototype is inspired by the pressure exchangers used in reverse-osmosis (RO) desalination systems. In this system, a 2D model was generated and modeled using the computational fluid dynamics (CFD) technique. The numerical model ignored any losses due to leakage or hydraulic friction and the process is considered adiabatic. For the modeling, it was assumed that the inlet conditions for the two pressure exchanger flows are similar to the flow conditions at the evaporator and gas cooler outlets in a VC cycle. Two parameters are examined to test the validity of the system and understand their effect on the performance, including the inlet flow rate represented by the inlet velocity and the process time represented by the speed of rotation. A total of nine cases were simulated and analyzed in this study.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2019

Modeling of Pressure Exchanger for Energy Recovery on Trans Critical CO2 Refrigeration Cycle

Pressure exchanger is a device used to recover energy from high pressure working fluid in systems like Reverse Osmosis water desalination. The pressure exchanger enables the high pressure fluid to transfer portion of its energy to the low pressure fluid by tran sferring the fluid pressure. This working concept can be applied to systems where there is a significant pressure variation of the working fluid along the system. Trans critical CO 2 refrigeration system is a good example for significant pressure variation during the flow path. The high pressure CO 2 exiting the condenser can be recovered by the low pressure CO 2 upstream of the compressor using a pressure exchanger to increase the system overall efficiency. The proposed research is to numerically simulate a prototype pressure exchanger for trans critical CO 2 refrigeration system. The focus of this study is to understand the thermo fluid behavior of the system when CO 2 is used as the working fluid. Contour plots of velocity and pressure are presented for qualitative analysis.

Elatar, Ahmed↗
DOE OSTI2026

A systematic analytical framework for multi-source municipal solid waste characterization for energy recovery

Advancing municipal solid waste (MSW) management from disposal-oriented practices toward circular, value-driven systems requires standardized methodologies capable of identifying material composition and resource recoverable potential at the point of generation. Despite extensive research, MSW characterization remains fragmented due to inconsistences in sampling methodologies, waste sorting categories, and temporal coverage across previous studies which limit cross-site comparability, reproducibility, and constrain the reliable evaluation of potential resource recovery pathways. This lack of consistency has hindered the development of a unified framework for MSW characterization and resource assessment. This study introduces a standardized, field-validated protocol for MSW sampling and composition analysis that ensures consistent, traceable data across diverse waste sources. The protocol integrates randomized spatial sampling, systematic material sorting, and controlled subsampling for multi-site and multi-season field campaigns. Validation included MSW collection from residential, grocery, restaurant, and school MSW streams across five U.S. states, including Maryland, Idaho, Virginia, Ohio, and Mississippi, to demonstrate the protocol’s ability to identify source-based composition patterns relevant to resource recovery applications. Grocery and restaurant streams were dominated by food waste and high-moisture organics, while school waste contained higher paper content and residential waste showed greater heterogeneity. Aggregation into energy-relevant fractions highlighted practical recovery pathways via anaerobic digestion or gasification, supporting data-driven planning, policy, and circular economy strategies for sustainable waste management across waste sources.

09 BIOMASS FUELS↗
DOE OSTI2024

Ion-specific phenomena limit energy recovery in forward-biased bipolar membranes

The ability for bipolar membranes (BPMs) to interconvert voltage and pH makes them attractive materials for use in energy conversion and storage. Reverse-biased BPMs, which use electrical voltage to dissociate water into acid and base, have become increasingly well studied. However, forward-biased BPMs (FB-BPMs), in which voltage is extracted from pH gradients through recombination, require further study. Here physics-based modeling elucidates how the complex coupling of transport and kinetics dictates the performance of FB-BPMs in electrochemical devices. Simulations reveal that the open-circuit potential of FB-BPMs is dictated by the balance of ion recombination and crossover, where recombination of buffering counter-ions attenuates the open-circuit potential. Counter-ion mass-transport limitations and uptake of ionic impurities limit achievable current densities by reducing the applied pH gradient or the available fixed-charge sites that mediate recombination. Further, the model highlights the importance of selective ion management in mitigating energy losses and provides insight into the rational material design of FB-BPMs for energy applications.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
NASA NTRS1985

Exploratory wind-tunnel investigation of a wingtip-mounted vortex turbine for vortex energy recovery

The Langley 8-foot transonic pressure tunnel was used for tests to determine the possibility of recovering, with a turbine-type device, part of the energy loss associated with the lift-induced vortex system. Tests were conducted on a semispan model with an unswept, untapered wing, with and without a wingtip-mounted vortex turbine. Three sets of turbine blades were tested to determine the effect of airfoil section shape and planform. The tests were conducted at a Mach number of 0.70 over an angle-of-attack range from 0 deg. to 4 deg. at a Reynolds number of 3.82 x 10 to the 6th power based on the wing reference chord of 13 in.

Patterson, J. C., Jr.↗
DOE OSTI2013

Energy recovery system using an organic rankine cycle

A thermodynamic system for waste heat recovery, using an organic rankine cycle is provided which employs a single organic heat transferring fluid to recover heat energy from two waste heat streams having differing waste heat temperatures. Separate high and low temperature boilers provide high and low pressure vapor streams that are routed into an integrated turbine assembly having dual turbines mounted on a common shaft. Each turbine is appropriately sized for the pressure ratio of each stream.

42 ENGINEERING↗
NASA NTRS1987

Energy Recovery

The United States and other countries face the problem of waste disposal in an economical, environmentally safe manner. A widely applied solution adopted by Americans is "waste to energy," incinerating the refuse and using the steam produced by trash burning to drive an electricity producing generator. NASA's computer program PRESTO II, (Performance of Regenerative Superheated Steam Turbine Cycles), provides power engineering companies, including Blount Energy Resources Corporation of Alabama, with the ability to model such features as process steam extraction, induction and feedwater heating by external sources, peaking and high back pressure. Expansion line efficiency, exhaust loss, leakage, mechanical losses and generator losses are used to calculate the cycle heat rate. The generator output program is sufficiently precise that it can be used to verify performance quoted in turbine generator supplier's proposals.

Source record↗
DOE OSTI2013

New Perspectives in Thermoelectric Energy Recovery System Design Optimization

Abstract: Large amounts of waste heat are generated worldwide in industrial processes, automotive transportation, diesel engine exhaust, military generators, and incinerators because 60-70% of the fuel energy is typically lost in these processes. There is a strong need to develop technologies that recover this waste heat to increase fuel efficiency and minimize fuel requirements in these industrial processes, automotive and heavy vehicle engines, diesel generators, and incinerators. There are additional requirements to reduce CO2 production and environmental footprints in many of these applications. Recent work with the Strategic Environmental Research and Development Program office has investigated new thermoelectric (TE) materials and systems that can operate at higher performance levels and show a viable pathway to lightweight, small form-factor, advanced thermoelectric generator (TEG) systems to recover waste heat in many of these applications. New TE materials include nano-composite materials such as lead-antimony-silver-telluride (LAST) and lead-antimony-silver-tin-telluride (LASTT) compounds. These new materials have created opportunities for high-performance, segmented-element TE devices. New higher-performance TE devices segmenting LAST/LASTT materials with bismuth telluride have been designed and fabricated. Sectioned TEG systems using these new TE devices and materials have been designed. Integrated heat exchanger/TE device system analyses of sectioned TE system designs have been performed creating unique efficiency-power maps that provide better understandings and comparisons of design tradeoffs and nominal and off-nominal system performance conditions. New design perspectives in optimization of sectioned TE design approaches are discussed that provide insight on how to optimize such sectioned TE systems. System performance analyses using ANSYS® TE modeling capabilities have integrated heat exchanger performance models with ANSYS® TE models to extend its analysis capabilities beyond simple constant hot-side and cold-side temperature conditions . Analysis results portray external resistance effects, matched load conditions, maximum power vs. maximum efficiency points simultaneously.

Energy Conversion↗
NASA NTRS1990

Wingtip vortex turbine investigation for vortex energy recovery

A flight test investigation has been conducted to determine the performance of wingtip vortex turbines and their effect on aircraft performance. The turbines were designed to recover part of the large energy loss (induced drag) caused by the wingtip vortex. The turbine, driven by the vortex flow, reduces the strength of the vortex, resulting in an associated induced drag reduction. A four-blade turbine was mounted on each wingtip of a single-engine, T-tail, general aviation airplane. Two sets of turbine blades were tested, one with a 15' twist (washin) and one with no twist. Th power recovered by the turbine and the installed drag increment were measured. A trade-off between turbine power and induced drag reduction was found to be a function of turbine blade incidence angle. This test has demonstrated that the wingtip vortex turbine is an attractive alternate, as well as an emergency, power source.

Abeyounis, William K.↗
DOE OSTI2015

Thermoelectric energy recovery at ionic-liquid/electrode interface

A thermally chargeable capacitor containing a binary solution of 1-ethyl-3-methylimidazolium bis(trifluoromethylsulfonyl)-imide in acetonitrile is electrically charged by applying a temperature gradient to two ideally polarisable electrodes. The corresponding thermoelectric coefficient is −1.7 mV/K for platinum foil electrodes and −0.3 mV/K for nanoporous carbon electrodes. Stored electrical energy is extracted by discharging the capacitor through a resistor. The measured capacitance of the electrode/ionic-liquid interface is 5 μF for each platinum electrode while it becomes four orders of magnitude larger, ≈36 mF, for a single nanoporous carbon electrode. Reproducibility of the effect through repeated charging-discharging cycles under a steady-state temperature gradient demonstrates the robustness of the electrical charging process at the liquid/electrode interface. The acceleration of the charging by convective flows is also observed. This offers the possibility to convert waste-heat into electric energy without exchanging electrons between ions and electrodes, in contrast to what occurs in most thermogalvanic cells.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2015

Measurement and simulation of the impact of coherent synchrotron radiation on the Jefferson Laboratory energy recovery linac electron beam

In an experiment conducted on the Jefferson Laboratory IR free-electron laser driver, the effects of coherent synchrotron radiation (CSR) on beam quality were studied. The primary goal of this work was to explore CSR output and effect on the beam with variation of the bunch compression in the IR recirculator. Here we examine the impact of CSR on the average energy loss as a function of bunch compression as well as the impact of CSR on the energy spectrum of the bunch. Simulation of beam dynamics in the machine, including the one-dimensional CSR model, shows very good agreement with the measured effect of CSR on the average energy loss as a function of compression. Finally, a well-defined structure is observed in the energy spectrum with a feature in the spectrum that varies as a function of the compression. This effect is examined in simulations, as well, and a simple explanation for the variation is proposed.

43 PARTICLE ACCELERATORS↗
NASA NTRS2024

Global Optimization via Quadratic Disjunctive Programming for Water Networks Design with Energy Recovery

Generalized disjunctive programming (GDP) models with bilinear and concave constraints, often seen in water network design, are challenging optimization problems. This work proposes quadratic and piecewise linear approximations for nonlinear terms to reformulate GDP models into quadratic GDP (QGDP) models that suitable solvers may solve more efficiently. We illustrate the benefits of the quadratic reformulation with a water treatment network design problem in which nonconvexities arise from bilinear terms in the mixers’ mass balances and concave investment cost functions of treatment units. Given the similarities with water network design problems, we suggest quadratic approximation for the GDP model for the optimal design of a large-scale reverse electrodialysis (RED) process. This power technology can recover energy from salinity differences between by-product streams of the water sector, such as desalination brine mixed with regenerated wastewater effluents. The solver Gurobi excels in handling QGDP problems, but weighing the problem’s precision and tractability balance is crucial. The piecewise linear approximation yields more accurate, yet larger QGDP models that may require longer optimization times in large-scale process synthesis problems.

Water Networks↗
DOE OSTI2023

The role of ionic blockades in controlling the efficiency of energy recovery in forward bias bipolar membranes

Limited understanding exists about the operation of bipolar membranes (BPMs) in forward bias to convert protonic gradients into electrical work, despite their emerging role in many electrochemical devices. In these device contexts, the BPM is typically exposed to complex electrolyte mixtures, but their impact on polarization remains poorly understood. Here, for this work, we develop a mechanistic model explaining the forward bias polarization behaviour of BPMs in mixed electrolytes with different acidities/basicities. This model invokes that weak acids/bases accumulate in the BPM and impose an ionic blockade that inhibits the recombination of stronger acids/bases, resulting in a substantial neutralization overpotential. We demonstrate the utility of our model for fuel cells and redox flow batteries and introduce two materials design strategies for mitigating this inhibition. Lastly, we apply our findings to enhance the energy efficiency of carbonate management in CO 2 electrolysers. This work highlights how non-equilibrium local environments at membrane–membrane interfaces can define the efficiency of protonic-to-electrical energy conversion.

25 ENERGY STORAGE↗