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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 379 records · Page 21
All sourcesNASA NTRSDOE OSTI
NASA NTRS1978

Cargo Logistics Airlift Systems Study (CLASS). Volume 3: Cross impact between the 1990 market and the air physical distribution systems, book 2

Book 2 of this volume is divided into the following sections: (1) commodities and system networks; (2) future mode choice decisions and commodity air eligibility; (3) comparative cargo transportation costs - air, truck, rail and water; (4) elasticities of demand; (5) operating cost; (6) operating profit, rate making, and returns; (7) importance of rate and service on future aircraft; (8) potential market demand for new aircraft; (9) scenario of events affecting system/market growth; and (10) future study and technology requirements.

Burby, R. J.↗
DOE OSTI2026

Development of Digital Twin-Informed Predictive Maintenance for Critical Components in Advanced Reactors

Small modular reactors (SMRs) and microreactors, along with other advanced reactor (AR) technologies, are key to the future of nuclear energy. For these systems to achieve low operating costs, high reliability, and flexibility across applications, their operation and maintenance must be optimized. Digital twin (DT) technology is one of the technologies that enables real-time (or faster than real-time) monitoring and prognosis of critical components which are vital for operational efficiency, low costs, and enhanced safety of ARs, accelerating their deployment. DT technology provides dynamic virtual representation of physical assets by integrating real-time data, physics-based models, and advanced analytics, which is critical to optimizing the performance of the entire energy system throughout the life cycle. DTs empower engineers and operators to virtually explore different scenarios, configurations, and control strategies, allowing for the identification of optimal solutions that maximize reactor efficiency, safety, and economics.

22 - GENERAL STUDIES OF NUCLEAR REACTORS↗
NASA NTRS1997

Applied Virtual Reality in Reusable Launch Vehicle Design, Operations Development, and Training

Application of Virtual Reality (VR) technology offers much promise to enhance and accelerate the development of Reusable Launch Vehicle (RLV) infrastructure and operations while simultaneously reducing developmental and operational costs. One of the primary cost areas in the RLV concept that is receiving special attention is maintenance and refurbishment operations. To produce and operate a cost effective RLV, turnaround cost must be minimized. Designing for maintainability is a necessary requirement in developing RLVs. VR can provide cost effective methods to design and evaluate components and systems for maintenance and refurbishment operations. The National Aeronautics and Space Administration (NASA)/Marshall Space Flight Center (MSFC) is beginning to utilize VR for design, operations development, and design analysis for RLVs. A VR applications program has been under development at NASA/MSFC since 1989. The objectives of the MSFC VR Applications Program are to develop, assess, validate, and utilize VR in hardware development, operations development and support, mission operations training and science training. The NASA/MSFC VR capability has also been utilized in several applications. These include: 1) the assessment of the design of the late Space Station Freedom Payload Control Area (PCA), the control room from which onboard payload operations are managed; 2) a viewing analysis of the Tethered Satellite System's (TSS) "end-of-reel" tether marking options; 3) development of a virtual mockup of the International Space Welding Experiment for science viewing analyses from the Shuttle Remote Manipulator System elbow camera and as a trainer for ground controllers; and 4) teleoperations using VR. This presentation will give a general overview of the MSFC VR Applications Program and describe the use of VR in design analyses, operations development, and training for RLVs.

Hale, Joseph P.↗
DOE OSTI2020

Resilient co-expansion planning between gas and electric distribution networks against natural disasters

Resiliently designed and constructed integrated gas-electric distribution networks (GEDNs) against natural disasters are crucial to social welfare. In this study, a two-stage robust optimisation-based co-expansion planning model is proposed to attain an integrated GEDN with a given resilience level, by optimising the investment strategies of hardening and selective expansion of power distribution feeders and natural gas pipelines, as well as the location and capacity of natural-gas-fired distributed generation. In the first stage, the overall annual investment and operation cost is minimised under normal operation conditions while in the second stage, the feasibility of the investment decisions under the identified worst-case natural disaster scenario is checked with an adjustable load shedding cost criterion. The proposed model is formulated as a mixed integer second-order cone programming problem with the column and constraint generation algorithm employed to seek the optimal solution. Case studies on two integrated GEDNs demonstrate the performance of the proposed methodology.

Zou, Bo↗
DOE OSTI2023

A Hot‐Swappable, Fault‐Tolerant, Modular Power Converter System for Solar Photovoltaic Plants

The performance metrics of the state-of-the-art commercial solar inverters, such as system cost, operation and maintenance (O&M) cost, service life, reliability, maintainability, and power density are much lower than the target metrics needed to achieve SunShot’s 2030 levelized cost of energy (LCOE) goals. To overcome the shortcomings of the existing solar inverters, this project proposed a novel Hot-Swappable, Fault-Tolerant, Modular Power Converter (HSFT-MPC) concept for solar photovoltaic (PV) plants and proved the concept through the design, fabrication, and laboratory test validation of a single-phase HSFT-MPC prototype. The HSFT-MPC has the following distinct advantages over the state-of-the-art: 1) elimination of harmonic/ electromagnetic interference (EMI) filter in the inverter stage due to the novel topology, 2) lower system cost and higher power density due to the modular design, elimination of harmonic/EMI filter, and lower cooling requirement, 3) higher efficiency due to lower switching frequencies, 4) higher reliability and longer (50 years) service life due to simpler cooling and fault tolerance capability, 5) easier installation, lower O&M cost, and improved maintainability due to the modular design and hot-swappable power electronic building blocks (PEBBs), and 6) improved manufacturability due to the modular design. This project developed a single-phase HSFT-MPC prototype with 25kW nominal output power, 2.4kV, 60Hz nominal AC output, lower than 5% AC output voltage total harmonic distortion, over 5 kW/L inverter power density, and 99.4% inverter peak efficiency, being tolerant to failure of single and multiple PEBBs, and capable of hot swapping of the failed PEBB(s). The HSFT-MPC enables uninterruptable operation of the solar PV plant when failure of single or multiple PEBBs or PV modules occurs. Compared with the existing solar inverters in the market, the HSFT-MPC is expected to reduce the inverter failure-caused downtime and energy losses of solar PV plants by more than 60% and 50%, respectively. Project findings have been presented at major conferences in the field and published in peer-reviewed papers, which added new knowledge to the field of power electronics for solar PV systems. A minicourse on Solar PV Systems was developed for outreach activities. The minicourse will help attract young individuals to the renewable energy profession which has a significant talent shortage. The HSFT-MPC is expected to overcome all of the shortcomings of the state-of-the-art solar inverters in terms of cost, efficiency, service life, reliability, maintainability, and manufacturability targets needed to achieve SunShot’s 2030 LCOE goals. Therefore, the proposed HSFT-MPC concept has the great potential to disrupt the current solar inverter market. This project created a pathway towards industry adoption of the HSFT-MPC to help achieve 50-year service life solar PV systems. Since the solar PV plants using the HSFT-MPC will feature with higher reliability, longer service life, and easier maintenance, they are particularly useful for the rural areas with underserved populations that demand reliable and affordable clean electricity. The outcomes of the project have the strong potential to address national needs in the field of renewable energy to reduce CO 2 emissions from the electricity sector, reduce imports of energy from foreign sources, and improve energy security, efficiency, and sustainability. Since electricity is used in almost all of society’s sectors, the outcomes of the project will benefit various sectors of society and economy.

14 SOLAR ENERGY↗
DOE OSTI2022

Application of a Novel Heat Pump Model for Estimating Economic Viability and Barriers of Heat Pumps in Dairy Applications in the United States

Heat pumps represent an important opportunity for energy savings and decarbonization. This work investigates the techno-economic performance of high-temperature heat pumps (HTHPs) for use in the U.S. dairy industry. The studied heat pump performs a 50 °C temperature lift on a waste heat stream of cleaning water and applies the upgraded heat stream to a fluid milk pasteurization process. This work involved the creation of a HTHP model that estimated the coefficient of performance (COP), internal rate of return (IRR), net present value (NPV), and payback period (PBP), and emissions saved for a heat pump replacing a natural gas boiler. Capital costs, operations, and maintenance (O&M) cost, heat pump lifetime, electricity prices, natural gas prices, and a cost of carbon were varied to perform a parametric study on the factors affecting the break-even price of HTHPs. The results show that HTHP economics are highly sensitive to COP and energy price environment, and less sensitive to capital and O&M cost variance, leading to a large scatter of positive and negative NPVs based on U.S. location. PBPs demonstrate a defined threshold, based on energy price environment, below which favorable two-to-three-year PBPs predominate. This work is focused on the U.S. dairy industry, but international application in relation to fossil vs. electricity price regimes. Heat pumps have seen wider adoption in regions with a high ratio of fossil energy to electricity prices ($/MMBTU vs. $/kWh). The U.S. has plentiful natural gas resulting in lower fossil energy prices which has reduced heat pump adoption. This paper identifies potential first mover industries for HTHP adoption and their associated price regimes even in regions with lower ratios of fossil energy to electricity prices that exist many places globally.

ENERGY CONSERVATION, CONSUMPTION, AND UTILIZATION,↗
DOE OSTI2023

Hybrid Electrochemical Hydrogen/Metal Hydride Compressor (Final Technical Report)

Various alternatives to traditional mechanical compressor systems have been considered, including MHC and EHC. Both MHCs and EHCs are solid-state systems that have no moving parts other than valves. Both are quiet and have low maintenance requirements. However, strength and material issues as well as water and heat management issues have challenged EHCs, especially, when operated at very high pressures. Similarly, low efficiency, especially, when staging is required to attain high, pressure ratios, has challenged MHCs and has made them too complex and expensive. Material degradation, due to hydrogen impurity effects, has also created issues for MHCs. One novel alternative evaluated here is to combine EHC and MHC technologies in a way to maximize their advantages and to minimize each of their challenges to improve the overall systems performance on a path to meet or exceed current DOE targets. A hybrid EH/MH compressor takes advantage of lower maintenance and operating costs as well as increased reliability associated with both the MHC and EHC technologies over traditional mechanical compressors. Neither the MHC nor the EHC have any moving parts other than valves. The hybrid system also takes advantage of the higher efficiency and lower cost of the EHC by operating at lower delivery pressures combined with the robust and simple operation of a single-stage, MH compressor at higher pressures. Both MHC and EHC technologies are scalable and can be used for a variety of hydrogen compression and delivery applications.

08 HYDROGEN↗
DOE OSTI2023

Diffractive Multiplexing for High-Throughput Roll-to-Roll Laser Patterning of Flexible Organic Photovoltaic Modules (Final Report)

The purpose of this project is to demonstrate a cost-effective, high-throughput roll-to-roll (R2R) process for patterning of flexible, semitransparent organic photovoltaic (OPV) modules by developing diffractive optics-based laser multiplexing (DOL Multiplexing). DOL Multiplexing allows a single, high-powered laser source to perform parallel scribing across the R2R web width in a manner compatible with high process speeds. Such a process could have enormous benefits in terms of increased process speeds and reduced costs, both up-front capital costs, and long-term operational costs, over galvanometer-based step and scan methods or many-laser systems.

14 SOLAR ENERGY↗
DOE OSTI2025

Deployment of Digital Twins and Advanced Instrumentation to Identify Looseness Between Rotor Spider Arms and Rim Attachment in Hydro Turbines

The project aimed to develop a Virtual Sensor Digital Twin (VS-DT) to monitor rotor rim float displacement (RRFD) in legacy hydropower turbines. RRFD, if undetected, can cause rotor and stator damage, leading to costly repairs and safety concerns. The purpose of the VS-DT was to predict RRFD signals using existing conventional sensors instead of installing dedicated, costly physical sensors, thereby reducing operational costs and enhancing safety.

13 HYDRO ENERGY↗
DOE OSTI2026

Stakeholder Questionnaire on Fish Passage Facilities at U.S. Hydropower Developments

To mitigate the environmental impacts of hydropower dams on fish populations in rivers, fish passage infrastructure may be required by regulatory authorities or recommended by state or federal agencies to allow migratory fish to pass hydropower barriers and complete their life histories. However, information on the location, types, and characteristics of fish passage infrastructure is incomplete at the national scale. This lack of information limits understanding of current fish passage capabilities and hinders efforts to anticipate future passage requirements during project licensing or relicensing. To address this knowledge gap, researchers at Oak Ridge National Laboratory partnered with federal agency and industry stakeholders to create the first national-scale database of fish passage infrastructure at U.S. hydropower developments. As part of this effort, a stakeholder questionnaire was created and deployed to solicit information on fish passage infrastructure, including engineering characteristics, operational schedules, targeted species, and costs. This online questionnaire was designed to allow respondents to provide highly detailed information regarding fish passage capabilities at U.S. hydropower developments as efficiently as possible. The questionnaire improved database coverage and accuracy by providing valuable development- or passage-specific stakeholder knowledge that is not otherwise publicly available. However, questionnaire response rates were low, and stakeholders showed a preference for providing data via the spreadsheet template. This is likely because most stakeholders had high-level knowledge about fish passage existence and type at many features, and few stakeholders had highly detailed, feature-specific knowledge of fish passage infrastructure, cost, operational scheduling, and capabilities. Nonetheless, the development and deployment of the stakeholder questionnaire advanced the project in several fundamental ways, and a similar questionnaire may be valuable for future database expansion via targeted dissemination to stakeholders with confirmed knowledge of detailed fish passage information at specific hydropower projects.

13 HYDRO ENERGY↗
NASA NTRS1977

Preliminary design study of advanced multistage axial flow core compressors

A preliminary design study was conducted to identify an advanced core compressor for use in new high-bypass-ratio turbofan engines to be introduced into commercial service in the 1980's. An evaluation of anticipated compressor and related component 1985 state-of-the-art technology was conducted. A parametric screening study covering a large number of compressor designs was conducted to determine the influence of the major compressor design features on efficiency, weight, cost, blade life, aircraft direct operating cost, and fuel usage. The trends observed in the parametric screening study were used to develop three high-efficiency, high-economic-payoff compressor designs. These three compressors were studied in greater detail to better evaluate their aerodynamic and mechanical feasibility.

Wisler, D. C.↗
NASA NTRS1978

Characteristics of constrained optimum trajectories with specified range

Necessary conditions of optimality are derived for trajectories whose structure is limited to climb, steady cruise, and descent segments. The performance function consists of the sum of fuel and time costs, referred to as direct operating cost (DOC). The state variable is range to go and the independent variable is energy. In this formulation a cruise segment always occurs at the optimum cruise energy for sufficiently large range. At short ranges (500 n. mi. and less) a cruise segment may also occur below the optimum cruise energy. The existence of such a cruise segment depends primarily on the fuel flow vs thrust characteristics and on thrust constraints. If thrust is a free control variable along with airspeed, it is shown that such cruise segments will not generally occur. If thrust is constrained to some maximum value in climb and to some minimum in descent, such cruise segments generally will occur. Computer calculations of typical short-range trajectories obtained about a 1% cost penalty for constraining the thrust.

Erzberger, H.↗
NASA NTRS1980

Constrained optimum trajectories with specified range

The characteristics of optimum fixed-range trajectories whose structure is constrained to climb, steady cruise, and descent segments are derived by application of optimal control theory. The performance function consists of the sum of fuel and time costs, referred to as direct operating costs (DOC). The state variable is range-to-go and the independent variable is energy. In this formulation a cruise segment always occurs at the optimum cruise energy for sufficiently large range. At short ranges (500 n. mi. and less) a cruise segment may also occur below the optimum cruise energy. The existence of such a cruise segment depends primarily on the fuel flow vs thrust characteristics and on thrust constraints. If thrust is a free control variable along with airspeed, it is shown that such cruise segments will not generally occur. If thrust is constrained to some maximum value in climb and to some minimum in descent, such cruise segments generally will occur. The performance difference between free thrust and constrained thrust trajectories has been determined in computer calculations for an example transport aircraft.

Erzberger, H.↗
NASA NTRS1981

Optimum climb and descent trajectories for airline missions

The characteristics of optimum fixed-range trajectories whose structure is constrained to climb, steady cruise, and descent segments are derived by application of optimal control theory. The performance function consists of the sum of fuel and time costs, referred to as direct operating cost (DOC). The state variable is range to go and the independent variable is energy. In this formulation a cruise segment always occurs at the optimum cruise energy for sufficiently large range. At short ranges (400 n. mi. and less), a cruise segment may also occur below the optimum cruise energy. The existence of such a cruise segment depends primarily on the fuel flow vs thrust characteristics and on thrust constraints. If thrust is a free control variable along with airspeed, it is shown that such cruise segments will not generally occur. If thrust is constrained to some maximum value in climb and to some minimum in descent, such cruise segments generally will occur.

Erzberger, H.↗
NASA NTRS1991

The propulsion system is the key to airline-like operation of ETO vehicles

The topics covered include the following: (1) Advanced Launch System (ALS); (2) life cycle cost/lb payload; (3) current operational cost; (4) major cost driver; (5) fully automated operations; (6) technology impacts on vehicle dry mass efficiency; (7) single stage to orbit (SSTO) approach; and (8) efficient SSTO propulsion system operations.

Obrien, Charles J.↗
NASA NTRS1996

Cassini tour cost reductions

The original design of the Cassini tour violated the cost constraint for the mission operations and data analysis by more than 30 percent. This challenge was addressed by performing tradeoffs in order to establish a modified risk and performance posture for the operations organization. This new posture accepted more data acquisition risk with minimal impact to the mission objectives, and brought the operation costs to within the program's constraints. The methodology employed within the Cassini program in order to address the tour cost, risk and performance parameters is presented.

Duxbury, J. H.↗
NASA NTRS2014

Misconceptions of Electric Propulsion Aircraft and Their Emergent Aviation Markets

Over the past several years there have been aircraft conceptual design and system studies that have reached conflicting conclusions relating to the feasibility of full and hybrid electric aircraft. Some studies and propulsion discipline experts have claimed that battery technologies will need to improve by 10 to 20 times before electric aircraft can effectively compete with reciprocating or turbine engines. However, such studies have approached comparative assessments without understanding the compelling differences that electric propulsion offers, how these technologies will fundamentally alter the way propulsion integration is approached, or how these new technologies can not only compete but far exceed existing propulsion solutions in many ways at battery specific energy densities of only 400 watt hours per kilogram. Electric propulsion characteristics offer the opportunity to achieve 4 to 8 time improvements in energy costs with dramatically lower total operating costs, while dramatically improving efficiency, community noise, propulsion system reliability and safety through redundancy, as well as life cycle Green House Gas emissions. Integration of electric propulsion will involve far greater degrees of distribution than existing propulsion solutions due to their compact and scale-free nature to achieve multi-disciplinary coupling and synergistic integration with the aerodynamics, highlift system, acoustics, vehicle control, balance, and aeroelasticity. Appropriate metrics of comparison and differences in analysis/design tools are discussed while comparing electric propulsion to other disruptive technologies. For several initial applications, battery energy density is already sufficient for competitive products, and for many additional markets energy densities will likely be adequate within the next 7 years for vibrant introduction. Market evolution and early adopter markets are discussed, along with the investment areas that will fill technology gaps and create opportunities for the effective, near-term electric aircraft products. Without understanding both the context of how electric propulsion will integrate into the vehicle system, and evolve into the market place it is likely that electric propulsion will continue to be misunderstood.

Moore, Mark D.↗