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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 433 records · Page 24
All sourcesNASA NTRSDOE OSTI
NASA NTRS2008

Mission Assessment of the Faraday Accelerator with Radio-frequency Assisted Discharge (FARAD)

Pulsed inductive thrusters have typically been considered for future, high-power, missions requiring nuclear electric propulsion. These high-power systems, while promising equivalent or improved performance over state-of-the-art propulsion systems, presently have no planned missions for which they are well suited. The ability to efficiently operate an inductive thruster at lower energy and power levels may provide inductive thrusters near term applicability and mission pull. The Faraday Accelerator with Radio-frequency Assisted Discharge concept demonstrated potential for a high-efficiency, low-energy pulsed inductive thruster. The added benefits of energy recapture and/or pulse compression are shown to enhance the performance of the pulsed inductive propulsion system, yielding a system that con compete with and potentially outperform current state-of-the-art electric propulsion technologies. These enhancements lead to mission-level benefits associated with the use of a pulsed inductive thruster. Analyses of low-power near to mid-term missions and higher power far-term missions are undertaken to compare the performance of pulsed inductive thrusters with that delivered by state-of-the-art and development-level electric propulsion systems.

Dankanich, John W.↗
NASA NTRS1982

On-orbit propulsion requirements and performance assessment of ion propulsion subsystems for future GEO large satellite missions

It is pointed out that a large class of future spacecraft, referred to as large space structures (LSS), will require advanced stationkeeping thrust subsystems. The present investigation is concerned with the performance requirements of such advanced stationkeeping thrust subsystems. An analytical model is employed to evaluate the sensitivity of the total stationkeeping thrust-system mass, for geosynchronous spacecraft, to variations in the mission parameters and thrust-system performance, taking into account ion propulsion thrust systems. The model is formulated for geosynchronous missions and considers only the N-S orbit perturbations due to sun-moon forces and the E-W orbit perturbations due to solar pressure, since these are the dominant orbit perturbations of LSS missions. The thrust system is scaled in relation to the performance capabilities of the existing 8- and 30-cm diameter ion-thruster technology and consists of separate N-S and E-W thrusters.

Wessel, F. J.↗
NASA NTRS1979

Energy efficient engine: Propulsion system-aircraft integration evaluation

Flight performance and operating economics of future commercial transports utilizing the energy efficient engine were assessed as well as the probability of meeting NASA's goals for TSFC, DOC, noise, and emissions. Results of the initial propulsion systems aircraft integration evaluation presented include estimates of engine performance, predictions of fuel burns, operating costs of the flight propulsion system installed in seven selected advanced study commercial transports, estimates of noise and emissions, considerations of thrust growth, and the achievement-probability analysis.

Owens, R. E.↗
NASA NTRS2011

Shuttle Propulsion System Major Events and the Final 22 Flights

Numerous lessons have been documented from the Space Shuttle Propulsion elements. Major events include loss of the Solid Rocket Boosters (SRB's) on STS-4 and shutdown of a Space Shuttle Main Engine (SSME) during ascent on STS-51F. On STS-112 only half the pyrotechnics fired during release of the vehicle from the launch pad, a testament for redundancy. STS-91 exhibited freezing of a main combustion chamber pressure measurement and on STS-93 nozzle tube ruptures necessitated a low liquid level oxygen cut off of the main engines. A number of on pad aborts were experienced during the early program resulting in delays. And the two accidents, STS-51L and STS-107, had unique heritage in history from early program decisions and vehicle configuration. Following STS-51L significant resources were invested in developing fundamental physical understanding of solid rocket motor environments and material system behavior. And following STS-107, the risk of ascent debris was better characterized and controlled. Situational awareness during all mission phases improved, and the management team instituted effective risk assessment practices. The last 22 flights of the Space Shuttle, following the Columbia accident, were characterized by remarkable improvement in safety and reliability. Numerous problems were solved in addition to reduction of the ascent debris hazard. The Shuttle system, though not as operable as envisioned in the 1970's, successfully assembled the International Space Station (ISS). By the end of the program, the remarkable Space Shuttle Propulsion system achieved very high performance, was largely reusable, exhibited high reliability, and was a heavy lift earth to orbit propulsion system. During the program a number of project management and engineering processes were implemented and improved. Technical performance, schedule accountability, cost control, and risk management were effectively managed and implemented. Award fee contracting was implemented to provide performance incentives. The Certification of Flight Readiness and Mission Management processes became very effective. A key to the success of the propulsion element projects was related to relationships between the MSFC project office and support organizations with their counterpart contractor organizations. The teams worked diligently to understand and satisfy requirements and achieve mission success.

Owen, James W.↗
NASA NTRS1992

Computation of magnetic suspension of maglev systems using dynamic circuit theory

Dynamic circuit theory is applied to several magnetic suspensions associated with maglev systems. These suspension systems are the loop-shaped coil guideway, the figure-eight-shaped null-flux coil guideway, and the continuous sheet guideway. Mathematical models, which can be used for the development of computer codes, are provided for each of these suspension systems. The differences and similarities of the models in using dynamic circuit theory are discussed in the paper. The paper emphasizes the transient and dynamic analysis and computer simulation of maglev systems. In general, the method discussed here can be applied to many electrodynamic suspension system design concepts. It is also suited for the computation of the performance of maglev propulsion systems. Numerical examples are presented in the paper.

He, J. L.↗
NASA NTRS2013

Revolutionary Aeropropulsion Concept for Sustainable Aviation: Turboelectric Distributed Propulsion

In response to growing aviation demands and concerns about the environment and energy usage, a team at NASA proposed and examined a revolutionary aeropropulsion concept, a turboelectric distributed propulsion system, which employs multiple electric motor-driven propulsors that are distributed on a large transport vehicle. The power to drive these electric propulsors is generated by separately located gas-turbine-driven electric generators on the airframe. This arrangement enables the use of many small-distributed propulsors, allowing a very high effective bypass ratio, while retaining the superior efficiency of large core engines, which are physically separated but connected to the propulsors through electric power lines. Because of the physical separation of propulsors from power generating devices, a new class of vehicles with unprecedented performance employing such revolutionary propulsion system is possible in vehicle design. One such vehicle currently being investigated by NASA is called the "N3-X" that uses a hybrid-wing-body for an airframe and superconducting generators, motors, and transmission lines for its propulsion system. On the N3-X these new degrees of design freedom are used (1) to place two large turboshaft engines driving generators in freestream conditions to minimize total pressure losses and (2) to embed a broad continuous array of 14 motor-driven fans on the upper surface of the aircraft near the trailing edge of the hybrid-wing-body airframe to maximize propulsive efficiency by ingesting thick airframe boundary layer flow. Through a system analysis in engine cycle and weight estimation, it was determined that the N3-X would be able to achieve a reduction of 70% or 72% (depending on the cooling system) in energy usage relative to the reference aircraft, a Boeing 777-200LR. Since the high-power electric system is used in its propulsion system, a study of the electric power distribution system was performed to identify critical dynamic and safety issues. This paper presents some of the features and issues associated with the turboelectric distributed propulsion system and summarizes the recent study results, including the high electric power distribution, in the analysis of the N3-X vehicle.

Kim, Hyun Dae↗
NASA NTRS1989

Mission Options for an Electric Propulsion Demonstration Flight Test

Several mission options are discussed for an electric propulsion space test which provides operational and performance data for ion and arcjet propulsion systems and testing of APSA arrays and a super power system. The results of these top-level studies are considered preliminary. Ion propulsion system design and architecture for the purposes of performing orbit raising missions for payloads in the range of 2400 to 2700 kg are described. Focus was placed on a design which can be characterized by simplicity, reliability, and performance. Systems of this design are suitable for an electric propulsion precursor flight which would provide proof of principle data necessary for more ambitious and complex missions.

Garner, Charles↗
NASA NTRS2014

Modular Pulsed Plasma Electric Propulsion System for Cubesats

Current capabilities of CubeSats must be improved in order to perform more ambitious missions. Electric propulsion systems will play a key role due to their large specific impulse. Compared to other propulsion alternatives, their simplicity allows an easier miniaturization and manufacturing of autonomous modules into the nano and pico-satellite platform. Pulsed Plasma Thrusters (PPTs) appear as one of the most promising technologies for the near term. The utilization of solid and non-volatile propellants, their low power requirements and their proven reliability in the large scale make them great candidates for rapid implementation. The main challenges are the integration and miniaturization of all the electronic circuitry into a printed circuit board (PCB) that can satisfy the strict requirements that CubeSats present. NASA Ames and the George Washington University have demonstrated functionality and control of three discrete Micro-Cathode Arc Thrusters (CAT) using a bench top configuration that was compatible with the ARC PhoneSat Bus. This demonstration was successfully conducted in a vaccum chamber at the ARC Environmental Test Laboratory. A new effort will integrate a low power Plasma Processing Unit and two plasma thrusters onto a single printed circuit board that will utilize less than 13 U of Bus volume. The target design will be optimized for the accommodation into the PhoneSatEDISON Demonstration of SmallSatellite Networks (EDSN) bus as it uses the same software interface application, which was demonstrated in the previous task. This paper describes the design, integration and architecture of the proposed propulsion subsystem for a planned Technology Demonstration Mission. In addition, a general review of the Pulsed Plasma technology available for CubeSats is presented in order to assess the necessary challenges to overcome further development.

PCB↗
NASA NTRS1974

Scramjet nozzle design and analysis as applied to a highly integrated hypersonic research airplane

The configuration and performance of the propulsion system for the hypersonic research vehicle are discussed. A study of the interactions between propulsion and aerodynamics of the highly integrated vehicle was conducted. The hypersonic research vehicle is configured to test the technology of structural and thermal protection systems concepts and the operation of the propulsion system under true flight conditions for most of the hypersonic flight regime. The subjects considered are: (1) research vehicle and scramjet engine configurations to determine fundamental engine sizing constraints, (2) analytical methods for computing airframe and propulsion system components, and (3) characteristics of a candidate nozzle to investigate vehicle stability and acceleration performance.

Small, W. J.↗
NASA NTRS2022

Genetic Optimization of Planetary Gearboxes Based on Analytical Gearing Equations

Electric and hybrid electric vertical takeoff and landing vehicles will require high performance electric motor driven propulsion systems to enable fuel burn and emissions benefits over traditional liquid fuel powered rotorcraft. One key to the design of a high performance electric motor driven propulsion systems is to be able to estimate the mass and efficiency of a gearbox at various motor and propellor operating speeds. Knowing how gearbox mass and efficiency trade with motor and propellor rotational speed, allows motor and propellor RPM to be traded in an overall optimization of the propulsion system. In this paper, a genetic optimization tool for estimating the mass and efficiency of gearboxes is presented. Example results from the tool are presented and compared to existing correlations in use by NASA aircraft design codes.

Thomas Tallerico↗
NASA NTRS2012

Characterization of Aerodynamic Performance of Boundary-Layer-Ingesting Inlet Under Crosswind

NASA has been studying future transport concepts, envisioned to be technically realizable in the timeframe of 2020-2030, to meet environmental and performance goals. One concept receiving considerable interest involves a propulsion system embedded into a hybrid wing-body aircraft. While offering significant advantages in fuel savings and noise reduction by this concept, there are several technical challenges that are not encountered in the current fleet and must be overcome so as to deliver target performance and operability. One of these challenges is associated with an inlet system that ingests a significantly thick boundary layer, developing along the wing-body surface, into a serpentine diffuser before the flow meeting fan blades. The flow is subject to considerable total pressure loss and distorted at the fan face, much more significantly than in the inlet system of conventional aircraft. In our previous studies [1, 2], we have shown that through innovative design changes on the airframe surface, it is possible to simultaneously increase total pressure recovery and decrease distortion in the flow, without resorting to conventional penalty-ridden flow control concepts, such as vortex generator or boundary layer bleeding/suction. In the current study, we are interested in understanding the following issues: how the embedded propulsion system performs under a crosswind condition by studying in detail the flow characteristics of two inlets, the baseline and another optimized previously under the cruise condition. With the insight, it is hoped that it can help in the follow-on study by devising effective strategies to minimize flow distortion arising from the integration of an embedded-engine system into an airframe to the level acceptable to the operation and fuel consumption before 2030. To achieve these demanding goals, non-conventional concepts are called for; but technology gap is too big that it requires evolutionary approach by focusing various concepts and technologies needed in the next three generations of aircraft, respectively named as N+1, N+2, and N+3. Noticeably, considerable reduction in each category of 1 is required in N+2 (relative to Boeing 777-200 and GE90 engines) and N+3 (relative to Boeing 737-800 and CFM56-7B engines). In this study, concepts for N+2 is our interest. A concept that has potential to achieve these metrics and has been under intensive study is the hybrid wing body (HWB) airframe with a tightly integrated propulsion system, see Fig. 1. The inlet is non-circular at the entrance and the entering flow, no longer uniform or free of disturbances, and is now carrying with it a boundary layer developing along the fuselage; the inlet is thus known as boundary-layer-ingesting (BLI) inlet.

Liou, Meng-Sing↗
NASA NTRS1997

(abstract) Final Galileo Propulsion System In-Flight Characterization (Extended Abstract)

The Galileo Retropropulsion Module (RPM) has performed excellently during nearly seven years of Galileo mission operations. The RPM was provided by the Federal Republic of Germany to NASA to provide directed impulse to the Galileo spacecraft during all phases of the Galileo mission following Inertial Upper Stage (IUS) jettison. This paper documents the in-flight performance of the Galileo propulsion system since July 1993.

Galileo Galileo Retropropulsion Module propellants↗
NASA NTRS1985

Performance and surge limits of a TF30-P-3 turbofan engine/axisymmetric mixed-compression inlet propulsion system at Mach 2.5

Steady-state performance and inlet-engine compatibility were investigated with a low-bleed inlet. The inlet had minimum internal contraction, consistent with high total pressure recovery and low cowl drag. The inlet-engine combination displayed good performance with only about 2% of inlet performance bleed. The inlet-engine combination had 5.58 deg angle-of-attack capability with 6% bleed.

Wasserbauer, J. F.↗
NASA NTRS2017

A Study of the Degradation of Electronic Speed Controllers for Brushless DC Motors

Brushless DC motors are frequently used in electric aircraft and other direct drive applications. As these motors are notactually direct current machines but synchronous alternating current machines; they are electronically commutated by a power inverter. The power inverter for brushless DC motors typically used in small scale UAVs is a semiconductor base delectronic commutator that is external to the motor and is referred to as an electronic speed control (ESC). This paper examines the performance changes of a UAV electric propulsion system resulting from ESC degradation. ESC performance is evaluated in simulation and on a new developed test bed featuring propulsion components from a reference UAV. An increase in the rise fall times of the switched voltages is expected to cause timing issues at high motor speeds. This study paves the way for further development of diagnostic and prognostic methods for inverter circuits which are part of the overall electric UAV system.

Gorospe, George E., Jr.↗
NASA NTRS1989

A perspective on future directions in aerospace propulsion system simulation

The design and development of aircraft engines is a lengthy and costly process using today's methodology. This is due, in large measure, to the fact that present methods rely heavily on experimental testing to verify the operability, performance, and structural integrity of components and systems. The potential exists for achieving significant speedups in the propulsion development process through increased use of computational techniques for simulation, analysis, and optimization. This paper outlines the concept and technology requirements for a Numerical Propulsion Simulation System (NPSS) that would provide capabilities to do interactive, multidisciplinary simulations of complete propulsion systems. By combining high performance computing hardware and software with state-of-the-art propulsion system models, the NPSS will permit the rapid calculation, assessment, and optimization of subcomponent, component, and system performance, durability, reliability and weight-before committing to building hardware.

Miller, Brent A.↗
NASA NTRS2016

Challenges and Progress in Aerodynamic Design of Hybrid Wingbody Aircraft with Embedded Engines

We summarize the contributions to high-fidelity capabilities for analysis and design of hybrid wingbody (HWB) configurations considered by NASA. Specifically, we focus on the embedded propulsion concepts of the N2-B and N3-X configurations, some of the future concepts seriously investigated by the NASA Fixed Wing Project. The objective is to develop the capability to compute the integrated propulsion and airframe system realistically in geometry and accurately in flow physics. In particular, the propulsion system (including the entire engine core-compressor, combustor, and turbine stages) is vastly more difficult and costly to simulate with the same level of fidelity as the external aerodynamics. Hence, we develop an accurate modeling approach that retains important physical parameters relevant to aerodynamic and propulsion analyses for evaluating the HWB concepts. Having the analytical capabilities at our disposal, concerns and issues that were considered to be critical for the HWB concepts can now be assessed reliably and systematically; assumptions invoked by previous studies were found to have serious consequences in our study. During this task, we establish firmly that aerodynamic analysis of a HWB concept without including installation of the propulsion system is far from realistic and can be misleading. Challenges in delivering the often-cited advantages that belong to the HWB are the focus of our study and are emphasized in this report. We have attempted to address these challenges and have had successes, which are summarized here. Some can have broad implications, such as the concept of flow conditioning for reducing flow distortion and the modeling of fan stages. The design optimization capability developed for improving the aerodynamic characteristics of the baseline HWB configurations is general and can be employed for other applications. Further improvement of the N3-X configuration can be expected by expanding the design space. Finally, the support of the System Analysis and Integration Element under the NASA Fixed Wing Project has enabled the development and helped deployment of the capabilities shown in this report.

design optimization↗
NASA NTRS2016

Overview of Iodine Propellant Hall Thruster Development Activities at NASA Glenn Research Center

NASA is continuing to invest in advancing Hall thruster technologies for implementation in commercial and government missions. There have been several recent iodine Hall propulsion system development activities performed by the team of the NASA Glenn Research Center, the NASA Marshall Space Flight Center, and Busek Co. Inc. In particular, the work focused on qualification of the Busek BHT-200-I, 200 W and the continued development of the BHT-600-I Hall thruster propulsion systems. This presentation presents an overview of these development activities and also reports on the results of short duration tests that were performed on the engineering model BHT-200-I and the development model BHT-600-I Hall thrusters.

Electric Propulsion↗