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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 865 records · Page 48
All sourcesNASA NTRSDOE OSTI
NASA NTRS2017

Multilayered Functional Insulation System (MFIS) for AC Power Transmission in High Voltage Hybrid Electrical Propulsion

High voltage hybrid electric propulsion systems are now pushing new technology development efforts for air transportation. A key challenge in hybrid electric aircraft is safe high voltage distribution and transmission of megawatts of power (>20 MW). For the past two years, a multidisciplinary materials research team at NASA Glenn Research Center has investigated the feasibility of distributing high voltage power on future hybrid electric aircraft. This presentation describes the team's approach to addressing this challenge, significant technical findings, and next steps in GRC's materials research effort for MW power distribution on aircraft.

high voltage power transmission↗
DOE OSTI2020

Performance of an Isobaric Hybrid Compressed Air Energy Storage System at Minimum Entropy Generation

Efficient, large-scale, and cost-effective energy storage systems provide a means of managing the inherent intermittency of renewable energy sources and drastically increasing their utilization. Compressed air energy storage (CAES) and its derivative architectures have received much attention as a viable solution; however, optimization objectives for these systems have not been thoroughly investigated in the literature. In this work, a hybrid thermal and compressed air energy storage (HT-CAES) system is investigated that mitigates the shortcomings of the otherwise attractive conventional CAES systems and its derivatives—shortcomings such as strict geological locations, low energy densities, and the production of greenhouse gas emissions. The HT-CAES system allows a portion of the available energy to operate a compressor and the remainder to be converted and stored in the form of heat through joule/resistive heating in a high-temperature, sensible, thermal energy storage medium. Internally reversible and irreversible HT-CAES system assumptions were investigated, in addition to regenerative and non-regenerative design configurations. Several system optimization criteria were examined—including maximum energy efficiency, maximum exergy efficiency, maximum work output, and minimum entropy generation—with a focus on whether the latter may lead to conclusive design guidelines in a real system. It is shown that an HT-CAES system designed based on a minimum entropy generation objective may operate at a lower energy and exergy efficiency as well as lower output power than otherwise achievable. Furthermore, optimization objective equivalence is shown to be limited to certain design conditions.

25 ENERGY STORAGE↗
DOE OSTI2021

Mg(BH 4 ) 2 -Based Hybrid Metal–Organic Borohydride System Exhibiting Enhanced Chemical Stability in Melt

The formation of a chemically stable and thermally cyclable Mg(BH 4 ) 2 melt is proven to be possible through the utilization of an organic borohydride salt additive. While extensive exploration of additives for lowering the melting point and modifying the chemical stability of Mg(BH 4 ) 2 has been reported, this is the first study to use the organic borohydride salt, tetramethylammonium borohydride (TMAB), to modify the melting behavior of Mg(BH 4 ) 2 . Here, examination of a 5:1 molar mixture of Mg(BH 4 ) 2 and TMAB revealed a reversible melt between 180 and 195 °C, which was reproduced for five thermal cycles. The mixture melt exhibited an enhanced chemical stability compared to melts of the individual Mg(BH 4 ) 2 and TMAB species. It was observed that between room temperature and 250 °C (over 50 °C above the melting point), the mixture releases <0.1 wt % mass, consisting primarily of H 2 . The mixture also exhibits greatly reduced evolution of volatile boron containing compounds compared to either Mg(BH 4 ) 2 or TMAB. The use of TMAB to chemically stabilize a Mg(BH 4 ) 2 -rich melt demonstrated in this work represents an exciting pathway to modification of Mg(BH 4 ) 2 relevant to both hydrogen-storage and magnesium battery fields.

08 HYDROGEN↗
DOE OSTI2021

Progress Towards Accelerating the Unified Model on Hybrid Multi-Core Systems

The cloud microphysics scheme, CASIM, and the radiation scheme, SOCRATES, are two computationally intensive parts within the Met Office's Unified Model (UM). This study enables CASIM and SOCRATES to use accelerated multi-core systems for optimal computational performance of the UM. Using profiling to guide our efforts, we refactored the code for optimal threading and kernel arrangement and implemented OpenACC directives manually or through the CLAW source-to-source translator. Initial porting results achieved 10.02x and 9.25x speedup in CASIM and SOCRATES respectively on 1 GPU compared with 1 CPU core. A granular performance analysis of the strategy and bottlenecks are discussed. These improvements will enable UM to run on heterogeneous computers and a path forward for further improvements is provided.

Zhang, Wei↗
DOE OSTI2025

Hybrid Bioenergy and Hydropower Systems: Leveraging Heterogeneous Biomass and Wastes from Watersheds

Sandia National Laboratories and INL explore the water-for-energy nexus in this white paper, focusing on the impact of heterogeneous watershed waste materials on hydropower facilities. They identify key challenges—such as wildfires, and debris intercepted at water intakes—that adversely affect both watershed health and hydropower operations. More importantly, SNL and INL highlight opportunities to valorize these bioresources and waste materials by converting them into usable energy.

09 BIOMASS FUELS↗
NASA NTRS1984

A study of aeroelastic and structural dynamic effects in multi-rotor systems with application to hybrid heavy lift vehicles

An aeroelastic model suitable for the study of aeroelastic and structural dynamic effects in multirotor vehicles simulating a hybrid heavy lift vehicle was developed and applied to the study of a number of diverse problems. The analytical model developed proved capable of modeling a number of aeroelastic problems, namely: (1) isolated blade aeroelastic stability in hover and forward flight, (2) coupled rotor/fuselage aeromechanical problem in air or ground resonance, (3) tandem rotor coupled rotor/fuselage problems, and (4) the aeromechanical stability of a multirotor vehicle model representing a hybrid heavy lift airship (HHLA). The model was used to simulate the ground resonance boundaries of a three bladed hingeless rotor model, including the effect of aerodynamic loads, and the theoretical predictions compared well with experimental results. Subsequently the model was used to study the aeromechanical stability of a vehicle representing a hybrid heavy lift airship, and potential instabilities which could occur for this type of vehicle were identified. The coupling between various blade, supporting structure and rigid body modes was identified.

Friedmann, P. P.↗
NASA NTRS1992

Human life support during interplanetary travel and domicile. VI - Generic modular flow schematic for hybrid physical/chemical-biological life support systems

An extension is proposed for the NASA Space Exploration Initiative's Generic Modular Flow Schematics for physical/chemical life support systems which involves the addition of biological processes. The new system architecture includes plant, microbial, and animal habitat, as well as the human habitat subsystem. Major Feedstock Production and Food Preparation and Packaging components have also been incorporated. Inedible plant, aquaculture, microbial, and animal solids are processed for recycling.

Ganapathi, Gani B.↗
NASA NTRS2002

Hybrid Active-Passive Systems for Control of Aircraft Interior Noise

It was proposed to continue with development and application in the two active-passive areas of Active Tuned Vibration Absorbers (ATVA) and smart foam applied to the reduction of interior noise in aircraft. In general the work was focused on making both techniques more efficient, practical and robust thus increasing their application potential. The work was also concerned with demonstrating the potential of these two technologies under realistic implementations as well as understanding the fundamental physics of the systems. The proposed work consisted of a three-year program and was tightly coordinated with related work being carried out in the Structural Acoustics Branch at NASA LaRC. The work was supervised and coordinated through all phases by Prof Chris Fuller of Va Tech.

Fuller, Chris R.↗
NASA NTRS2017

Technology Development and Design of an Electrically Driven Pump Fed (EDPF) Bi-Propellant Propulsion System for a Mars Ascent Vehicle (MAV)

A Mars Ascent Vehicle (MAV), as part of a potential Mars Sample Return (MSR) campaign, is a very unique challenge and has been the focus of technology development and design efforts at JPL (Jet Propulsion Lab.) for several decades. Recent trajectory studies, for the current range of notional MAV payloads (6-25 kilograms), evaluated performance using propulsion systems in the 2.5 kiloNewton to 4.5 kiloNewton (600-1000 pounds-force) thrust range. The study examined several propulsion system approaches - solid rocket, bi-propellant and hybrid propulsion systems - and developed a ranking based on several key figures of merit. This paper focuses on the evaluations conducted for the two bi-propellant propulsion system options considered for a potential MAV. Historically, bi-propellant propulsion systems have been considered for this application; this study took a fresh look at both a conventional State of the Art (SOA) pressure fed bi-propellant propulsion system and recent developments using small EDPF (Electrically-Driven Pump-Fed) bi-propellant propulsion systems.

Vaughan, David↗
NASA NTRS2017

Evaluation of a Variable Thickness Hybrid Composite Bull Gear

For several years, NASA Glenn Research Center and the U.S. Army Research Laboratory have been investigating hybrid (composite/steel) gear technology for use in vertical lift drive systems. The hybrid gear concept replaces the structural portion of a gear between the shaft and the gear rim with a lightweight carbon fiber composite, in an effort to reduce the overall weight of a gear and increase the drive system power density. Past research includes both small-scale and large-scale hybrid gear concepts, all of which have a constant composite thickness throughout. The design described in this paper is of a variable thickness, such that the composite is thickest at the inner diameter and this thickness is gradually reduced toward the outer diameter. The resulting "stair stepped" design stems from dropping plies of the braided carbon fiber prepreg composite fabric gradually with increased radius. Additionally, the interlock pattern at the inner metallic adapter was adjusted slightly from previous designs to obtain a better stress distribution on the inner metallic adapter. The manufactured variable thickness web was tested both in static torsion tests and operationally in a relevant gearbox environment. The results of these experiments will be presented and compared to a baseline steel configuration.

Gears; Drive Systems; Rotorcraft Propulsion;↗