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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 883 records · Page 49
All sourcesNASA NTRSDOE OSTI
NASA NTRS2015

Combining Solar Electric Propulsion and Chemical Propulsion for Crewed Missions to Mars

This paper documents the results of an investigation of human Mars mission architectures that leverage near-term technology investments and infrastructures resulting from the planned Asteroid Redirect Robotic Mission (ARRM), including high-power Solar Electric Propulsion (SEP) and a human presence in Lunar Distant Retrograde Orbit (LDRO). The architectures investigated use a combination of SEP and chemical propulsion elements. Through this combination of propulsion technologies, these architectures take advantage of the high efficiency SEP propulsion system to deliver cargo, while maintaining the faster trip times afforded by chemical propulsion for crew transport. Evolved configurations of the Asteroid Redirect Vehicle (ARV) are considered for cargo delivery. Sensitivities to SEP system design parameters, including power level and propellant quantity, are presented. For the crew delivery, liquid oxygen and methane stages were designed using engines common to future human Mars landers. Impacts of various Earth departure orbits, Mars loiter orbits, and Earth return strategies are presented. The use of the Space Launch System for delivery of the various architecture elements was also investigated and launch vehicle manifesting, launch scheduling and mission timelines are also discussed. The study results show that viable Mars architecture can be constructed using LDRO and SEP in order to take advantage of investments made in the ARRM mission.

Percy, Tom↗
NASA NTRS2015

Combining Solar Electric and Chemical Propulsion for Crewed Missions to Mars

This paper documents the results of an investigation of human Mars mission architectures that leverage near-term technology investments and infrastructures resulting from the planned Asteroid Redirect Mission, including high-power Solar Electric Propulsion (SEP) and a human presence in Lunar Distant Retrograde Orbit (LDRO). The architectures investigated use a combination of SEP and chemical propulsion elements. Through this combination of propulsion technologies, these architectures take advantage of the high efficiency SEP propulsion system to deliver cargo, while maintaining the faster trip times afforded by chemical propulsion for crew transport. Evolved configurations of the Asteroid Redirect Vehicle (ARV) are considered for cargo delivery. Sensitivities to SEP system design parameters, including power level and propellant quantity, are presented. For the crew delivery, liquid oxygen and methane stages were designed using engines common to future human Mars landers. Impacts of various Earth departure orbits, Mars loiter orbits, and Earth return strategies are presented. The use of the Space Launch System for delivery of the various architecture elements was also investigated and launch vehicle manifesting, launch scheduling and mission timelines are also discussed. The study results show that viable Mars architecture can be constructed using LDRO and SEP in order to take advantage of investments made in the ARM mission.

Percy, Tom↗
DOE OSTI2021

Co-Design of a Fully Electric Hybrid Hydraulic-Electric Architecture (FE-HHEA) for Off-Road Mobile Machines

Off-road mobile machines, such as excavators and wheel-loaders, are typically actuated by hydraulics using internal combustion engines as their power sources. There is a trend towards fully electrifying these machines and improving their efficiencies due to environmental regulations and concerns. In this paper, a control co-design methodology is used to design a Fully Electrified Hybrid Hydraulic-Electric Architecture (FE-HHEA) for an excavator that drastically reduces energy consumption and minimizes the sizes of costly electric components. By optimizing both control operation and the physical design, the co-design methodology takes into account the interaction between these two aspects. The design methodology also illustrates how the system architecture evolves from the previously developed IC engine powered HHEA with the engine replaced by an electric motor to a seemingly very different architecture with fewer components. The optimized system reduces energy consumption by 71% over the baseline system and uses electrical components that are 1/3 the size of an alternate fully electric architecture.

33 ADVANCED PROPULSION SYSTEMS↗
DOE OSTI2021

Lieb-Robinson Light Cone for Power-Law Interactions

The Lieb-Robinson theorem states that information propagates with a finite velocity in quantum systems on a lattice with nearest-neighbor interactions. What are the speed limits on information propagation in quantum systems with power-law interactions, which decay as 1 / r α at distance r ? Here, we present a definitive answer to this question for all exponents α > 2 d and all spatial dimensions d . Schematically, information takes time at least r min { 1 , α - 2 d } to propagate a distance r . As recent state transfer protocols saturate this bound, our work closes a decades-long hunt for optimal Lieb-Robinson bounds on quantum information dynamics with power-law interactions.

71 CLASSICAL AND QUANTUM MECHANICS, GENERAL PHYSIC↗
DOE OSTI2023

Feedback-Based Fault-Tolerant and Health-Adaptive Optimal Charging of Batteries

The key technology barriers that hinder the growth of Electric Vehicles (EVs) are long charging time, the shorter life-time of EV batteries, and battery safety. Specifically, EV charging protocols have significant effects on battery lifetime and safety. If not charged properly, the battery could end up with shorter life, and more importantly, improper charging can cause battery faults leading to catastrophic failures. To overcome these barriers, we propose a closed-loop feedback based approach, that enables real-time optimal fast charging protocol adaptation to battery health and possess active diagnostic capabilities in the sense that, during charging, it detects real-time faults and takes corrective action to mitigate such fault effects. We utilize battery electrical-thermal model, explicit battery capacity and power fade aging models, and thermal fault model to capture battery behavior. In conjunction with the models, we adopt linear quadratic optimal control techniques to realize the feedback-based control algorithm. Simulation studies are presented to illustrate the effectiveness of the proposed scheme.

batteries↗
DOE OSTI2020

Multiscale modeling of microwave-heated multiphase systems

Modeling of microwave heating of multiphase systems requires resolving the electromagnetic field from the single particle to the entire cavity. We introduce a multiscale methodology for computationally affordable simulations of microwave heating of multiphase systems consisting of one phase dispersed in a continuum phase. The methodology homogenizes the original multiphase system, by taking advantage of the large separation of length scales, to calculate the effective permittivity, effective thermal conductivity, and volumetric power absorbed in each phase. The methodology is rigorously assessed against particle-resolved detailed numerical simulations of model systems. We demonstrate a significant reduction in computational cost while retaining the accuracy of detailed simulations. Lastly, the present methodology enables high throughput exploration of novel multiphase system designs utilizing microwave heating.

37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CH↗
DOE OSTI2020

Super-CMB fluctuations and the Hubble tension

We study the covariance in the angular power spectrum estimates of CMB fluctuations when the primordial fluctuations are non-Gaussian. The non-Gaussian covariance comes from a nonzero connected four-point correlation function -- or the trispectrum in Fourier space -- and can be large when long-wavelength (super-CMB) modes are strongly coupled to short-wavelength modes. The effect of such non-Gaussian covariance can be modeled through additional freedom in the theoretical CMB angular power spectrum and can lead to different inferred values of the standard cosmological parameters relative to those in ΛCDM. Taking the collapsed limit of the primordial trispectrum in the quasi-single field inflation model as an example, we study how the six standard ΛCDM parameters shift when two additional parameters describing the trispectrum are allowed. The reduced statistical significance of the Hubble tension in the extended model allows us to combine the {\it Planck} temperature data and the type Ia supernovae data from Panstarrs with the distance-ladder measurement of the Hubble constant. Here, this combination of data shows strong evidence for a primordial trispectrum-induced non-Gaussian covariance, with a likelihood improvement of Δχ 2 ≈ –15 (with two additional parameters) relative to ΛCDM.

79 ASTRONOMY AND ASTROPHYSICS↗
DOE OSTI2022

Broadband piezoelectric energy harvesting microgyroscopes: Design and nonlinear analysis

Small devices in remote or difficult-to-reach areas can benefit from harvesting energy from mechanical wasted energy, which reduces the requirement for a new power source. A multi-purpose energy harvesting microgyroscope system based on piezoelectric materials is suggested. The necessity of taking spatially varying electrostatic forces is examined. Considering the effects of the system's width and thickness, DC voltage, and angular speed the systems inherent frequencies are found. The partial differential equations describing the system's dynamics are numerically solved by using the differential quadrature method. Further, the numerical analysis enables to identify the optimal system design for broadband energy harvesting. The simulation results reveal that a system with a non-symmetric beam design is adequate for broadband energy harvesting. This is associated with the applied DC voltage, which may be modified to improve the broadband frequency of the system. It is concluded that the nonlinear softening effects create a broadband frequency response with high voltage output. However, DC and AC voltages need to be carefully selected in order to avoid the dynamic pull-in.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2025

Control of core–shell nanoparticles properties through plasma synthesis: a computational study

The improved properties of core–shell nanoparticles (CSNPs) over homogeneous nanoparticles (NPs) have expanded and diversified the applications of these nanomaterials. However, controlling the properties of CSNPs can be a challenging task. Low temperature plasmas have proven to be an effective method of producing NPs with uniform size and morphology, and high yield. That said, NP transport and growth dynamics are sensitive to LTP properties. We report on a computational investigation of the evolution of Ge–Si CSNP properties as a function of operating conditions through the modeling of a flowing, two-zone inductively coupled plasma (ICP) reactor. Ar/GeH 4 and Ar/SiH 4 gas mixtures were supplied to separate plasma zones at a pressure of 1 Torr to promote growth of Ge cores and Si shells. The negatively charged CSNPs are trapped electrostatically in the vicinity of the antennas where the plasma is generated and where the majority of particle growth occurs. Particles that grow to a critical size are then de-trapped by fluid drag due to neutral gas flow. A two-dimensional hybrid plasma model coupled with a three-dimensional kinetic NP transport model were utilized to resolve plasma chemistry and NP growth processes that take place on distinct timescales. The trends in CSNP properties and trapping mechanisms associated with flow rate, applied ICP power and inlet precursor fraction are discussed. While the spatial distribution of plasma produced radical species can have significant impact on the NP growth process, the NP transport dynamics are what ultimately dictates the growth environment that is unique to each particle and so determines their final dimension and composition. The key to optimizing reactor conditions involves controlling the spatial density of growth species and plasma profile as a means to tailor particle trapping dynamics suitable to produce CSNPs for a specific application.

36 MATERIALS SCIENCE↗
DOE OSTI2023

A Machine Learning Framework to Deconstruct the Primary Drivers for Electricity Market Price Events

As the electricity grid is moving towards a 100% Renewable Energy Source Bulk Power Grid, the overall operations of the power system operations and electricity markets are changing. The electricity markets are not only dispatching resources economically but also taking into account various controllable actions like renewable curtailment, transmission congestion mitigation, and energy storage optimization to make sure the grid is operating reliably. As a result, price formations in electricity markets have become quite complex. Traditional root cause analysis and statistical approaches are rendered inapplicable to analyze and infer the main drivers behind price formation in the modern grid and markets with variable renewable energy (VRE). In this paper, we propose a machine learning analysis framework to deconstruct some primary drivers for price formation in modern electricity markets with high renewable energy and the outcomes can be utilized for various critical aspects of market design, renewable dispatch and curtailment, operations, and cyber-security applications. The framework can be applied to any ISO or market data and in this paper it is applied to open-source publicly available datasets from California Independent System Operator (CAISO) and ISO New England.

machine learning (ML), electricity markets, Renewa↗
DOE OSTI2021

A Bulk-Capacitance Reduction Method Using Self-Driven Thyristor for AC-DC Converters

Universal serial bus power delivery (USB-PD) fast chargers equipped with wide-bandgap devices are driven to higher power density and efficiency. Furthermore, the indispensable high-voltage bulk capacitors used to smooth the rectifier output could take 40% of the total system volume due to the large capacitance value required. This paper discussed a capacitor reduction method using a self-driven thyristor scheme comprised of only three components in total. No extra control circuit is needed. Circuit analysis and design equations are presented, and the design results are implemented in a 60-W GaN-based active-clamp flyback converter. The measurement results on the prototype show a 36.4% reduction of the bulk-capacitor size with similar efficiency compared to the conventional solution.

30 DIRECT ENERGY CONVERSION↗
DOE OSTI2026

The NEXT-100 Detector

The NEXT collaboration is dedicated to the study of double beta decays of 136 Xe using a high-pressure gas electroluminescent time projection chamber. This advanced technology combines exceptional energy resolution (≤ 1% FWHM at the Q ββ value of the neutrinoless double beta decay) and powerful topological event discrimination. Building on the achievements of the NEXT-White detector, the NEXT-100 detector started taking data at the Laboratorio Subterráneo de Canfranc (LSC) in May of 2024. Designed to operate with xenon gas at 13.5 bar, NEXT-100 consists of a time projection chamber where the energy and the spatial pattern of the ionising particles in the detector are precisely retrieved using two sensor planes (one with photo-multiplier tubes and the other with silicon photo-multipliers). The detector has been operating at stable conditions using argon and xenon gases at ~4 bar and drift fields of 74 V cm –1 and 118 V cm –1 , respectively. Alpha decays from the 222 Rn chain have been used to test and monitor the stability of the detector, showing a constant electron lifetime in the drift volume. In this paper, in addition to reporting the results of the commissioning run, we provide a detailed description of the NEXT-100 detector, describe its assembly, and present the current estimation of the radiopurity budget.

Adams, C. [Argonne National Laboratory; NVIDIA] (O↗
NASA NTRS1976

A program for calculating turbofan-driven lift-fan propulsion system performance

The performance of a turbofan-powered lift fan propulsion system for vertical takeoff and landing (VTOL) aircraft is calculated. The program formulation consists of taking bleed air from a turbofan engine, heating the bleed air in an interburner, and passing it through a tip turbine to drive a lift fan. Two options are available: bleed air from the engine exhaust, or bleed air that has passed through the engine fan only. This computer program will benefit persons unfamiliar with the thermodynamics of engine cycle analysis.

Tauber, M. E.↗
NASA NTRS1979

Flight test evaluation of predicted light aircraft drag, performance, and stability

A technique was developed which permits simultaneous extraction of complete lift, drag, and thrust power curves from time histories of a single aircraft maneuver such as a pullup (from V sub max to V sub stall) and pushover (to sub V max for level flight.) The technique is an extension to non-linear equations of motion of the parameter identification methods of lliff and Taylor and includes provisions for internal data compatibility improvement as well. The technique was show to be capable of correcting random errors in the most sensitive data channel and yielding highly accurate results. This technique was applied to flight data taken on the ATLIT aircraft. The drag and power values obtained from the initial least squares estimate are about 15% less than the 'true' values. If one takes into account the rather dirty wing and fuselage existing at the time of the tests, however, the predictions are reasonably accurate. The steady state lift measurements agree well with the extracted values only for small values of alpha. The predicted value of the lift at alpha = 0 is about 33% below that found in steady state tests while the predicted lift slope is 13% below the steady state value.

Smetana, F. O.↗
NASA NTRS1982

NECAP 4.1: NASA's Energy-Cost Analysis Program fast input manual and example

NASA's Energy-Cost Analysis Program (NECAP) is a powerful computerized method to determine and to minimize building energy consumption. The program calculates hourly heat gain or losses taking into account the building thermal resistance and mass, using hourly weather and a response factor method. Internal temperatures are allowed to vary in accordance with thermostat settings and equipment capacity. NECAP 4.1 has a simplified input procedure and numerous other technical improvements. A very short input method is provided. It is limited to a single zone building. The user must still describe the building's outside geometry and select the type of system to be used.

Jensen, R. N.↗
NASA NTRS1983

NECAP 4.1: NASA's energy-cost analysis program user's manual

The Enery Cost Analysis Program (NECAP) is a powerful computerized method to determine and to minimize building energy consumption. The program calculates hourly heat gain or losses taking into account the building thermal resistance and mass, using hourly weather and a "response factor' method. Internal temperatures are allowed to vary in accordance with thermostat settings and equipment capacity. A simplified input procedure and numerous other technical improvements are presented. This Users Manual describes the program and provides examples.

Jensen, R. N.↗
NASA NTRS1984

Electromechanical/electromagnetics working group summary

The component and system technology issues associated with suspension and power conversion systems for the flywheel were discussed. The development of the technology consists of three major steps and encompasses a complementary mix of analytical efforts and hardware development for validation of design approaches and concept implementations. The major elements included: (1) studies to determine the optimal system configuration considering gimballed and nongimballed wheel concepts and incorporating the best 1984 component technology. These studies must also address the impact of rotor configuration on other elements of the system such as motor/generators and magnetic suspension systems to permit the selection of the optimal configuration for the demonstration phase; (2) focus the development program on integration and demonstration of a complete system which includes the rotor, suspension, and power conversion subsystems which emphasis efficiency; (3) conduct a technology program on motor/generators, suspension systems, gimbals, and sensors to take advantage of known technological advances.

Eisenhaure, D. B.↗
NASA NTRS1984

The pilot climate data system

The Pilot Climate Data System (PCDS) is an interactive scientific information management system for locating, obtaining, manipulating, and displaying climate-research data. The PCDS was developed to manage a large collection of data of interest to the National Aeronautics and Space Administration's (NASA) research community and currently provides such support for approximately twenty data sets. In order to provide the PCDS capabilities, NASA's Goddard Space Flight Center (NASA/GSFC) has integrated the capabilities of several general-purpose software packages with specialized software for reading and reformatting the supported data sets. These capabilities were integrated in a manner which allows the PCDS to be easily expanded, either to provide support for additional data sets or to provide additional functional capabilities. This also allows the PCDS to take advantage of new technology as it becomes available, since parts of the system can be replaced with more powerful components without significantly affecting the user interface.

Reph, M. G.↗