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Search indexed NASA NTRS and DOE OSTI research on propulsion, heat transfer, battery materials and energy systems. Follow report and document links to the original sources.

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At least 1,441 records · Page 80
All sourcesNASA NTRSDOE OSTI
DOE OSTI2024

On Building Predictive Digital Twin Incorporating Wave Predicting Capabilities: Case Study on UMaine Experimental Campaign - FOCAL

The response of floating wind turbines (FWT) are susceptible to stochastic wave variations. For the optimal operation of FWT, a comprehensive understanding of the phaseresolved wave dynamics and the consequential system response is crucial for real-time monitoring and control. A multi-variate, multi-step, long short term memory (MLSTM), a type of recurrent neural network (RNN) is used to capture complex system dynamics for real-time application. Results indicate that the integration of a wave prediction-reconstruction (WRP) model substantially enhances prediction accuracy by 50% on average relative to the baseline model. The improvement is consistent across various wave extremity and prediction horizons, thereby significantly broadening the scope for timely and precise predictive capabilities.

17 WIND ENERGY↗
DOE OSTI2024

Classical field approximation of ultralight dark matter: Quantum break times, corrections, and decoherence

The classical field approximation is widely used to better understand the predictions of ultralight dark matter. Here, in this work, we use the truncated Wigner approximation method to test the classical field approximation of ultralight dark matter. This method approximates a quantum state as an ensemble of independently evolving realizations drawn from its Wigner function. The method is highly parallelizable and allows the direct simulation of quantum corrections and decoherence times in systems many times larger than have been previously studied in reference to ultralight dark matter. Our study involves simulation of systems in 1, 2, and 3 spatial dimensions. We simulate three systems, the condensation of a Gaussian random field in three spatial dimensions, a stable collapsed object in three spatial dimensions, and the merging of two stable objects in two spatial dimensions. We study the quantum corrections to the classical field theory in each case. We find that quantum corrections grow exponentially during nonlinear growth with the timescale being approximately equal to the system dynamical time. In stable systems the corrections grow quadratically. We also find that the primary effect of quantum corrections is to reduce the amplitude of fluctuations on the de Broglie scale in the spatial density. Finally, we find that the timescale associated with decoherence due to gravitational coupling to baryonic matter is at least as fast as the quantum corrections due to gravitational interactions. These results are consistent with the predictions of the classical field theory being accurate.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2014

Biomass Scenario Model Scenario Library: Definitions, Construction, and Description

Understanding the development of the biofuels industry in the United States is important to policymakers and industry. The Biomass Scenario Model (BSM) is a system dynamics model of the biomass-to-biofuels system that can be used to explore policy effects on biofuels development. Because of the complexity of the model, as well as the wide range of possible future conditions that affect biofuels industry development, we have not developed a single reference case but instead developed a set of specific scenarios that provide various contexts for our analyses. The purpose of this report is to describe the scenarios that comprise the BSM scenario library. At present, we have the following policy-focused scenarios in our library: minimal policies, ethanol-focused policies, equal access to policies, output-focused policies, technological diversity focused, and the point-of-production- focused. This report describes each scenario, its policy settings, and general insights gained through use of the scenarios in analytic studies.

09 BIOMASS FUELS↗
DOE OSTI2014

Performance Verification of Production-Scalable Energy-Efficient Solutions: Winchester/Camberley Homes Mixed-Humid Climate

Winchester/Camberley Homes with the Building America program and its NAHB Research Center Industry Partnership collaborated to develop a new set of high performance home designs that could be applicable on a production scale. The new home designs are to be constructed in the mixed humid climate zone four and could eventually apply to all of the builder's home designs to meet or exceed future energy codes or performance-based programs. However, the builder recognized that the combination of new wall framing designs and materials, higher levels of insulation in the wall cavity, and more detailed air sealing to achieve lower infiltration rates changes the moisture characteristics of the wall system. In order to ensure long term durability and repeatable successful implementation with few call-backs, this report demonstrates through measured data that the wall system functions as a dynamic system, responding to changing interior and outdoor environmental conditions within recognized limits of the materials that make up the wall system. A similar investigation was made with respect to the complete redesign of the heating, cooling, air distribution, and ventilation systems intended to optimize the equipment size and configuration to significantly improve efficiency while maintaining indoor comfort. Recognizing the need to demonstrate the benefits of these efficiency features, the builder offered a new house model to serve as a test case to develop framing designs, evaluate material selections and installation requirements, changes to work scopes and contractor learning curves, as well as to compare theoretical performance characteristics with measured results.

2X6 WALLS↗
DOE OSTI2014

Performance Verification of Production-Scalable Energy-Efficient Solutions: Winchester/Camberley Homes Mixed-Humid Climate

Winchester/Camberley Homes collaborated with the Building America team Partnership for Home Innovation to develop a new set of high performance home designs that could be applicable on a production scale. The new home designs are to be constructed in the mixed humid climate zone and could eventually apply to all of the builder's home designs to meet or exceed future energy codes or performance-based programs. However, the builder recognized that the combination of new wall framing designs and materials, higher levels of insulation in the wall cavity, and more detailed air sealing to achieve lower infiltration rates changes the moisture characteristics of the wall system. In order to ensure long term durability and repeatable successful implementation with few call-backs, the project team demonstrated through measured data that the wall system functions as a dynamic system, responding to changing interior and outdoor environmental conditions within recognized limits of the materials that make up the wall system. A similar investigation was made with respect to the complete redesign of the HVAC systems to significantly improve efficiency while maintaining indoor comfort. Recognizing the need to demonstrate the benefits of these efficiency features, the builder offered a new house model to serve as a test case to develop framing designs, evaluate material selections and installation requirements, changes to work scopes and contractor learning curves, as well as to compare theoretical performance characteristics with measured results.

2x6 walls↗
DOE OSTI2013

Electric Drive Dynamic Thermal System Model for Advanced Vehicle Propulsion Technologies: Cooperative Research and Development Final Report, CRADA Number CRD-09-360

Electric drive systems, which include electric machines and power electronics, are a key enabling technology for advanced vehicle propulsion systems that reduce the dependence of the U.S. transportation sector on petroleum. However, to penetrate the market, these electric drive technologies must enable vehicle solutions that are economically viable. The push to make critical electric drivesystems smaller, lighter, and more cost-effective brings respective challenges associated with heat removal and system efficiency. In addition, the wide application of electric drive systems to alternative propulsion technologies ranging from integrated starter generators, to hybrid electric vehicles, to full electric vehicles presents challenges in terms of sizing critical components andthermal management systems over a range of in-use operating conditions. This effort focused on developing a modular modeling methodology to enable multi-scale and multi-physics simulation capabilities leading to generic electric drive system models applicable to alternative vehicle propulsion configurations. The primary benefit for the National Renewable Energy Laboratory (NREL) is the abilityto define operating losses with the respective impact on component sizing, temperature, and thermal management at the component, subsystem, and system level. However, the flexible nature of the model also allows other uses related to evaluating the impacts of alternative component designs or control schemes depending on the interests of other parties.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2017

PDCI Wide-Area Damping Control: PSLF Simulations of the 2016 Open and Closed Loop Test Plan

To demonstrate and validate the performance of the wide-are a damping control system, the project plans to conduct closed-loop tests on the PDCI in summer/fall 2016. A test plan details the open and closed loop tests to be conducted on the P DCI using the wide-area damping control system. To ensure the appropriate level of preparedness, simulations were performed in order to predict and evaluate any possible unsafe operations before hardware experiments are attempted. This report contains the result s from these simulations using the power system dynamics software PSLF (Power System Load Flow, trademark of GE). The simulations use the WECC (Western Electricity Coordinating Council) 2016 light summer and heavy summer base cases.

24 POWER TRANSMISSION AND DISTRIBUTION↗
DOE OSTI2017

PDCI Wide-Area Damping Control: PSLF Simulations of the 2017 Test Plan - Light Summer Case

To demonstrate and validate the performance of the wide-area damping control system, the project plans to conduct closed-loop tests on the PDCI in spring/summer 2017. A test plan details the open and closed loop tests to be conducted on the PDCI using the wide-area damping control system. To ensure the appropriate level of preparedness, simulations were performed in order to predict and evaluate any possible unsafe operations before hardware experiments are attempted. This report contains the results from these simulations using the power system dynamics software PSLF (Power System Load Flow, trademark of GE). The simulations use the WECC (Western Electricity Coordinating Council) 2016 light summer and heavy summer base cases and the 2014 dual export base case. Because of the large volume of plots, the results were divided into three reports corresponding to the three base cases. This report contains results from the 2016 light summer base case.

25 ENERGY STORAGE↗
DOE OSTI2017

PDCI Wide-Area Damping Control: PSLF Simulations of the 2017 Test Plan - Heavy Summer Case

To demonstrate and validate the performance of the wide-area damping control system, the project plans to conduct closed-loop tests on the PDCI in spring/summer 2017. A test plan details the open and closed loop tests to be conducted on the PDCI using the wide-area damping control system. To ensure the appropriate level of preparedness, simulations were performed in order to predict and evaluate any possible unsafe operations before hardware experiments are attempted. This report contains the results from these simulations using the power system dynamics software PSLF (Power System Load Flow, trademark of GE). The simulations use the WECC (Western Electricity Coordinating Council) 2016 light summer and heavy summer base cases and the 2014 dual export base case. Because of the large volume of plots, the results were divided into three reports corresponding to the three base cases. This report contains results from the 2016 heavy summer base case.

25 ENERGY STORAGE↗
DOE OSTI2017

PDCI Wide-Area Damping Control: PSLF Simulations of the 2017 Test Plan - Dual Export Case

To demonstrate and validate the performance of the wide-area damping control system, the project plans to conduct closed-loop tests on the PDCI in spring/summer 2017. A test plan details the open and closed loop tests to be conducted on the PDCI using the wide-area damping control system. To ensure the appropriate level of preparedness, simulations were performed in order to predict and evaluate any possible unsafe operations before hardware experiments are attempted. This report contains the results from these simulations using the power system dynamics software PSLF (Power System Load Flow, trademark of GE). The simulations use the WECC (Western Electricity Coordinating Council) 2016 light summer and heavy summer base cases and the 2014 dual export base case. Because of the large volume of plots, the results were divided into three reports corresponding to the three base cases. This report contains results from the 2014 dual export base case.

25 ENERGY STORAGE↗