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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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NASA NTRS1989

Integrated flight/propulsion control study for STOVL applications

The STOVL Integrated Flight Propulsion Controls (IFPC) Program, initiated by NASA Lewis and NASA Ames to develop the necessary technologies for integrating the flight and propulsion controls of a future STOVL aircraft, is described. A major element of the STOVL IFPC Program is the STOVL Controls Integration Program (SCIP), which focuses on the development of an integrated flight propulsion control for the advanced vectored thrust STOVL concept. The SCIP has progressed to the point of generating top level control requirements.

Mihaloew, James R.↗

DOE OSTI2024

Improving the National Solar Radiation Database (NSRDB) Using a Physics-Based Direct Normal Irradiance (DNI) Model

The National Solar Radiation Database (NSRDB) is a widely used resource providing satellite-derived solar data across the United States and globally. While the NSRDB employs a physical model for computing global horizontal irradiance (GHI), its current method for estimating cloudy-sky direct normal irradiance (DNI) relies on surface observations and empirical models. Recently, a novel physics-based approach, the Fast All-Sky Radiation Model for Solar applications with DNI (FARMS-DNI), was developed to enhance the DNI forecasting. FARMS-DNI incorporates both direct and scattered solar radiation within the circumsolar region, resulting in improved day-ahead DNI predictions when integrated into the Weather Research and Forecasting model with Solar extensions (WRF-Solar). This study integrates FARMS-DNI into the NSRDB algorithm to generate high-resolution DNI data from satellite resources. Our findings reveal that FARMS-DNI effectively mitigates the substantial DNI overestimation present in the conventional NSRDB across surface sites, particularly in conditions categorized as cloudy overcast. Consequently, this innovative model substantially enhances the overall accuracy of the NSRDB.

Xie, Yu↗

NASA NTRS1992

High-speed research program systems analysis activities at Ames Research Center

The Ames Systems Analysis Branch has been working to support the High Speed Research Program (HSRP) for nearly one year. Both the status of methodology development activities and the results of studies are presented whether completed or underway. The discussion involves the conceptual design synthesis program used for High Speed Civil Transport (HSCT) studies, ACSYNT (aircraft synthesis), and enhancements that have been made especially for HSRP. Some results are presented for one study that has been completed and two that are underway. These are the advanced controls integration study, the fuel cost impact study, and the oblique wing configuration evaluation that is part of a larger innovative concepts study.

Kidwell, George H.↗

NASA NTRS2004

A Review of the Match Technique as Applied to AASE-2/EASOE and SOLVE/THESEO 2000

We apply the GSFC trajectory model with a series of ozonesondes to derive ozone loss rates in the lower stratosphere for the AASE-2/EASOE mission (January - March 1992) and for the SOLVE/THESEO 2000 mission (January - March 2000) in an approach similar to Match. Ozone loss rates are computed by comparing the ozone concentrations provided by ozonesondes launched at the beginning and end of the trajectories connecting the launches. We investigate the sensitivity of the Match results on the various parameters used to reject potential matches in the original Match technique and conclude that only a filter based on potential vorticity changes along the calculated back trajectory seems necessary. Our study also demonstrates that calculated ozone loss rates can vary by up to a factor of two depending upon the precise trajectory paths calculated for each trajectory. As a result an additional systematic error might need to be added to the statistical uncertainties published with previous Match results. The sensitivity to the trajectory path is particularly pronounced in the month of January, the month during which the largest ozone loss rate discrepancies between photochemical models and Match are found. For most of the two study periods, our ozone loss rates agree with those previously published. Notable exceptions are found for January 1992 at 475 K and late February/early March 2000 at 450 K, both periods during which we find less loss than the previous studies. Integrated ozone loss rates in both years compare well with those found in numerous other studies and in a potential vorticity/potential temperature approach shown previously and in this paper. Finally, we suggest an alternate approach to Match using trajectory mapping that appears to more accurately reflect the true uncertainties associated with Match and reduces the dependence upon filters that may bias the results of Match through the rejection of greater than or equal to 80% of the matched sonde pairs and >99% of matched observations.

Morris, Gary A.↗

DOE OSTI2024

Improving the National Solar Radiation Database (NSRDB) Using a Physics-Based Direct Normal Irradiance (DNI) Model: Preprint

DNI↗

NASA NTRS1984

A summary of the 1983 Integrated Flywheel Technology Workshop

The use of flywheels to perform the functions of attitude control and/or energy storage on a variety of space missions was studied. Integrated Flywheel Technology was discussed. The four primary objectives are: (1) determine the potential of flywheels for energy storage system applications and for combined energy storage and attitude control concepts; (2) assess the state of the art (SOA) in integrated flywheel technology through a review of government sponsored programs; (3) identify those technology areas which are in critical need of development to meet projected space mission requirements; (4) scope a program for the coordinated development of the required technology.

Keckler, C. R.↗

DOE OSTI2023

Fine-scale evaluation of two standard 16S rRNA gene amplicon primer pairs for analysis of total prokaryotes and archaeal nitrifiers in differently managed soils

The advance of high-throughput molecular biology tools allows in-depth profiling of microbial communities in soils, which possess a high diversity of prokaryotic microorganisms. Amplicon-based sequencing of 16S rRNA genes is the most common approach to studying the richness and composition of soil prokaryotes. To reliably detect different taxonomic lineages of microorganisms in a single soil sample, an adequate pipeline including DNA isolation, primer selection, PCR amplification, library preparation, DNA sequencing, and bioinformatic post-processing is required. Besides DNA sequencing quality and depth, the selection of PCR primers and PCR amplification reactions arguably have the largest influence on the results. This study tested the performance and potential bias of two primer pairs, i.e., 515F (Parada)-806R (Apprill) and 515F (Parada)-926R (Quince) in the standard pipelines of 16S rRNA gene Illumina amplicon sequencing protocol developed by the Earth Microbiome Project (EMP), against shotgun metagenome-based 16S rRNA gene reads. The evaluation was conducted using five differently managed soils. We observed a higher richness of soil total prokaryotes by using reverse primer 806R compared to 926R, contradicting to in silico evaluation results. Both primer pairs revealed various degrees of taxon-specific bias compared to metagenome-derived 16S rRNA gene reads. Nonetheless, we found consistent patterns of microbial community variation associated with different land uses, irrespective of primers used. Total microbial communities, as well as ammonia oxidizing archaea (AOA), the predominant ammonia oxidizers in these soils, shifted along with increased soil pH due to agricultural management. In the unmanaged low pH plot abundance of AOA was dominated by the acid-tolerant NS-Gamma clade, whereas limed agricultural plots were dominated by neutral-alkaliphilic NS-Delta/NS-Alpha clades. This study stresses how primer selection influences community composition and highlights the importance of primer selection for comparative and integrative studies, and that conclusions must be drawn with caution if data from different sequencing pipelines are to be compared.

16S rRNA gene amplicon Illumina sequencing↗

DOE OSTI2022

Time-dependent THMC properties and microstructural evolution of damaged rocks in excavation damage zone

Modeling coupled thermo-hydro-mechanical-chemical (THMC) processes in host rocks near high-level nuclear waste (HLW) repositories at various time scales is an extremely challenging task. The current study integrates experimental, theoretical, and numerical methods in assessing the evolution of excavation damage zone (EDZ) over time and its implication on the long-term migration of hazardous species. Argillite and rock salt and are the focus of this study. The first part of the report presents a novel time-dependent directional microcrack damage theory for generic brittle rocks. It features detailed statistical description of the microcracks within a damaged solid, permitting a direct upscaling of microscale processes such as crack growth kinetics, crack closure/opening, sliding friction to explain the macroscopic creep, nonlinear elasticity, shear dilation, and loading-unloading hysteresis. This provides a basic platform for describing the anisotropic mechanical and transport properties of damaged rocks during excavation and subsequent THMC loadings. The model is validated and numerically implemented to Finite Element (FE) package ABAQUS through the user-defined material (UMAT) interface and have demonstrated great potential in resolving the time-dependent and anisotropic evolution of damage in the EDZ. The second part of the report presents a multi-scale experimental effort in characterizing the thermal, hydraulic, and mechanical properties of Mancos shale and Avery Island salt. For the Mancos shale, triaxial compression tests are performed at different confining pressures and temperatures to probe its thermomechanical properties relevant to HLW repositories. The obtained stress-strain data are interpreted using the proposed directional damage theory. Post-test specimens are subjected to gas permeability tests to reveal the correlation between permeability and the degree of microcracking. At microscale, temperature-controlled nanoindentation tests are performed and found a linear correlation between fracture toughness and elastic modulus from 25°C to 300°C. For Avery Island salt, we have designed and manufactured a novel relative-humidity controlled uniaxial creep device. Long-term creep tests at low stresses (< 5 MPa) are performed at different levels of relative humidity (RH). Besides confirming the much higher creep rates as one would expect through extrapolating the high-stress creep data, the results reveal that the steady-state creep rate of rock salt is strongly dependent on the ambient RH, an aspect that is often neglected in the literature. Both behaviors can be attributed to the pressure-solution creep mechanism which dominates at low stress and high RH levels. The third part of the report explores a set of numerical strategies in modeling the THMC behavior of porous geomaterials. A fully implicit, monolithic FE solution that can flexibly interface with different material models and coupling mechanisms for THMC problems is developed and verified through the ABAQUS user-defined element (UEL) interface. The scheme is used to study the THM response of a hypothetical HLW storage site with reference to an existing in-situ heater test. Strategies for integrating the UEL and the microcrack UMAT are suggested. Another numerical endeavor of this study is to implement a higher-order asymptotic homogenization method to account for the heterogeneous porous structures. The same method is then extended to perform microstructure-informed thermo-mechanical modeling of generalized continua. The above outcomes of this project provide a strong thrust towards enhancing the fundamental understanding and modeling capability of the long-term evolution of host rocks in EDZ, thus helping achieve the design goal of 1-million-year isolation of high-level nuclear wastes.

11 NUCLEAR FUEL CYCLE AND FUEL MATERIALS↗

DOE OSTI2025

Hybrid data-driven cement-stabilized soil design: An integration of machine learning, multi-objective optimization, and life cycle assessment

Soil stabilization is crucial in geotechnical engineering, yet conventional methods are often time-consuming, resource-intensive, and environmentally unsustainable. Despite growing interest in Machine Learning (ML) and optimization tools for mix design, few studies integrate these methods with decision-making techniques and environmental assessment to support practical implementation. This study proposes a hybrid data-driven framework for predicting strength, optimizing mix compositions, and evaluating environmental impacts via life cycle assessment of cement-stabilized soft soils. Six ML models were evaluated, and the top-performing eXtreme Gradient Boosting (XGB) model was further improved using the Grey Wolf Optimizer (GWO). The optimized XGB-GWO model, integrated with a polynomial cost function, served as the objective function in a multi-objective optimization problem solved via the Non-Dominated Sorting Genetic Algorithm II (NSGA-II), with final mix selection guided by the entropy-weighted TOPSIS method. Validation through a case study produced mix designs offering superior strength-cost trade-offs, with the optimal mix achieving 2243.2 kPa unconfined compressive strength and a 16.07 % reduction in carbon emissions compared to the highest-cost design. In conclusion, this study offers a sustainable, scalable approach to soil stabilization and supports informed decision-making in construction.

Life cycle assessment↗

NASA NTRS1980

A laser rangefinder path selection system for Martian rover using logarithmic scanning scheme

This paper deals with a laser rangefinder path selection scheme for an autonomous Martian roving vehicle. The overall scheme consists of the following interrelated sub-systems; logarithmic scanning sub-system, obstacle detection scheme (Sonalkar and Shen (1975); Kim and Shen (1978)), terrain modeling and estimation (Shen and Stare (1977); Pawlowski (1978)), and path selection algorithm (Netch and Shen (1977)). Independent and separate studies for the last three sub-systems were performed previously. With the introduction of the logarithmic scanning, an integrated study is completed in this paper. This study serves as a possible alternate choice other than TV cameras for navigating the Martian surface. Moreover, if hybrid TV and laser systems are used, a laser-only standby system can be put to work in case the TV part of the hybrid system fails to operate.

Shen, C. N.↗

NASA NTRS1982

On the stability of Schwarzschild's triaxial galaxy model

The numerical model for a triaxial galaxy constructed by Schwartzschild (1979) has been tested by means of fully self-consistent three-dimensional n-body numerical experiments that use a representation of this model to start the integration. The integration, study models, initial load, and correcting potential of the experiment are detailed. Preliminary checks included density values, potential values, and integration in potential of an ideal model. The results showed some particle loss and no significant shape change. The model is rugged and robust, and no growing disturbances with growth rate in excess of 0.5 per crossing time could be detected. Runs were done at 50 percent excess halo and with tube orbits reversed.

Smith, B. F.↗

NASA NTRS2022

Low-Speed Performance Enhancement using Localized Active Flow Control: Program Overview and Summary (1/4)

The Boeing team executed a NASA task order, titled “Low Speed Performance Enhancement using Localized Active Flow Control”, under the BAART framework NNL16AA04B, contract number 80LARC20F0082. The project was executed from Sept. 2020 through April 2022 with the objective to explore localized active flow control (AFC) concepts on a representative commercial aircraft. A detailed literature review solidified the choice of AFC concepts to be explored, including AFC over a deflected aileron, in the leading edge region of the wing, and in the nacelle/pylon/wing region. All three concepts were investigated with numerical tools. The results were used in an integration study to assess the net benefits over the lifetime of a commercial aircraft. The aerodynamic studies concluded that AFC applied over a deflected aileron yields significant net L/D improvements (incl. the penalty of AFC system requirements) of up to potentially 5% L/D. Depending on the configuration, AFC applied in the leading edge region showed improvements in L/D of up to ~1.5%, as well as opportunities for maximum lift and increased lift at fixed angle of attack. AFC applied to the nacelle/pylon/wing region delivered 1.5% increase in L/D during take-off and ~4% increase in CLmax during landing. After considering assumed onboard sources, aspects of system integration and weight penalties, these aerodynamic improvements translate to: ~ 0.5% block fuel reduction potential for AFC over the aileron ~ 0.1% block fuel reduction potential for AFC in the LE slat region ~ 0.2% block fuel reduction potential for AFC in the nacelle/pylon/wing region considering take-off scenarios (potentially larger benefit may be realized considering the landing scenarios which haven’t been fully analyzed yet) The final report is comprised of four separate documents. The current document provides an overview and technical background. The second document details the numerical studies and the third document summarizes the integration and aircraft performance assessment. The fourth document focuses on the Common Research Model, specifically how AFC performs over a deflected aileron and how the NASA 10% scale wind tunnel model may be modified to implement an AFC equipped aileron. Each report offers significantly more detailed summaries and suggestions for future work.

Active flow control↗

NASA NTRS1975

Life sciences manned payloads for Shuttle/Spacelab

This paper summarizes the highlights of the NASA/MSFC Life Sciences Payload Definition and Integration studies. Four closely related studies describing research requirements, engineering analysis, and design concepts for a family of life sciences laboratories are reviewed. The study approach was based upon a broad laboratory capability to do research in medicine, biology, life support and protective systems, and man-systems integration. This laboratory design concept provides the flexibility desired for the changing requirements of a long-term space program. Designs of the resulting conceptual laboratories that satisfy the research goals are presented. The on-going NASA program activity to support future life sciences involvement in the Spacelab is outlined.

Heppner, D. B.↗

NASA NTRS2023

Flow Control for Enhanced Aileron Effectiveness on a Commercial Aircraft

Active flow control was applied to the ailerons of a representative future short/medium-range twin-engine airplane to improve aerodynamic performance during high-lift operations. The study is aimed at reduced drag and enhanced lift over the range of practical angles of attack, including stall. These benefits translate to airplane performance improvements, such as longer range or larger payload. Various flow control techniques were explored using Computational Fluid Dynamics and the aerodynamic performance enhancements were benchmarked against the baseline configuration. The computational analyses are used to quantify aerodynamic benefits, as well as the input required for actuation. The results were used in a system integration study for identifying potential practical implementations, which are described in a companion paper. Combined with the integration analysis, the objective of this project is to identify the most promising flow control candidates that potentially provide material net airplane level enhancements using onboard fluidic sources. The current study indicates that up to 5% net improvement in L/D at takeoff is potentially achievable using active flow control on the aileron, after accounting for factors of system integration.

CFD↗

NASA NTRS1981

Predesign study for a modern 4-bladed rotor for the NASA rotor systems research aircraft

Trade-off study results and the rationale for the final selection of an existing modern four-bladed rotor system that can be adapted for installation on the Rotor Systems Research Aircraft (RSRA) are reported. The results of the detailed integration studies, parameter change studies, and instrumentation studies and the recommended plan for development and qualification of the rotor system is also given. Its parameter variants, integration on the RSRA, and support of ground and flight test programs are also discussed.

Bishop, H. E.↗

NASA NTRS2023

Applications of Flow Control to Wing High-Lift Leading Edge Devices on a Commercial Aircraft

Active flow control was applied to the leading edge region of a representative future short/medium-range twin-engine airplane to improve aerodynamic performance during high-lift operations. The study is aimed at enhanced lift over the practical angle of attack range, including stall, and at reduced drag. These benefits translate to airplane performance improvements, such as longer range or larger payload. Various flow control applications were explored using Computational Fluid Dynamics and the aerodynamic performance enhancements were benchmarked against the baseline configuration. The computational analyses are used to quantify aerodynamic benefits, as well as the input required for actuation. The results were used in a system integration study for identifying potential practical implementations, which are described in a companion paper. Combined with the integration analysis, the objective of this project is to identify the most promising flow control candidates that potentially provide material net airplane level enhancements using onboard fluidic sources. Depending on the implementation of active flow control, the current study indicates that up to 1.5% net improvement in L/D at takeoff and 4% increase in maximum lift during landing are potentially achievable, after accounting for factors of system integration.

CFD↗

DOE OSTI2023

Integration of discrete-event dynamics and machining dynamics for machine tool: Modeling, analysis and algorithms

Machining dynamics research lays a solid foundation for machining operations by providing stable combinations of spindle speed and depth of cut. Furthermore, machine learning has been applied to predict tool life as a function of cutting speed. However, the existing research does not consider the discrete-event dynamics in machine shop, i.e., the machine tool needs to process a series of parts in queue under various practical production requirements. This paper addresses the integration of discrete-event dynamics and machining dynamics to achieve cost savings in machining. A learning-based cost function is first proposed for the studied integrated optimization problem of machine tool. The proposed cost function utilizes the predicted tool life under different stable cutting speeds for further optimizing speed selection of machine tool to deal with the discrete-event dynamics in machine shop. Then, according to the practical production requirements, effective mathematical optimization models are developed for the related integrated optimization problems with the consideration of cost, makespan and due date, respectively. Numerical results show the effectiveness of our proposed methods and also the potential to be used in practice.

Ma, Mason↗

DOE OSTI2023

Exploiting electricity market dynamics using flexible electrolysis units for retrofitting methanol synthesis

Here we investigate the economic viability of integrating flexible electrolysis units to produce hydrogen in methanol synthesis processes. Specifically, we investigate whether this approach can help reduce methanol production costs by strategically exploiting dynamics of electricity markets. Our study integrates high-fidelity process simulations, optimization tools, and microkinetic modeling (informed by density functional theory) to conduct detailed techno-economic analyses and to compare performance against traditional processes that use hydrogen produced via steam-methane reforming (SMR). We also use this approach to estimate the levelized cost of hydrogen (LCOH) as a function of time-varying electricity prices (from day-ahead and real-time prices) and of key techno-economic parameters. Our results show that the proposed electrification framework is cost-competitive under certain electricity market conditions. Specifically, we find that, when the electrolysis system is operated in flexible mode (and can respond to dynamics of electricity markets), the associated electricity cost nearly collapses to zero. Conversely, when the unit is not flexible (and cannot respond to markets), the electricity cost comprises 60% of the total cost. Our results also reveal that the LCOH of the flexible electrolysis system participating in real-time electricity markets is 31% lower than the LCOH obtained from SMR. Overall, this indicates that exploiting the dynamics of electricity markets can make hydrogen production cost-competitive and this can lead to viable alternatives to electrify methanol production and other hydrogen-based processes.

29 ENERGY PLANNING, POLICY, AND ECONOMY↗