Propulsion

About: Propulsion is a research topic. Over the lifetime, 24977 publications have been published within this topic receiving 200311 citations.

X-57 power and command system design

Abstract: This paper describes the power and command system architecture of the X-57 Maxwell flight demonstrator aircraft. The X-57 is an experimental aircraft designed to demonstrate radically improved aircraft efficiency with a 3.5 times aero-propulsive efficiency gain at a “high-speed cruise” flight condition for comparable general aviation aircraft. These gains are enabled by integrating the design of a new, optimized wing and a new electric propulsion system. As a result, the X-57 vehicle takes advantage of the new capabilities afforded by electric motors as primary propulsors. Integrating new technologies into critical systems in experimental aircraft poses unique challenges that require careful design considerations across the entire vehicle system, such as qualification of new propulsors (motors, in the case of the X-57 aircraft), compatibility of existing systems with a new electric power distribution bus, and instrumentation and monitoring of newly qualified propulsion system devices.

Initial Assessment of Open Rotor Propulsion Applied to an Advanced Single-Aisle Aircraft

Abstract: Application of high speed, advanced turboprops, or propfans, to subsonic transport aircraft received significant attention and research in the 1970s and 1980s when fuel efficiency was the driving focus of aeronautical research. Recent volatility in fuel prices and concern for aviation s environmental impact have renewed interest in unducted, open rotor propulsion, and revived research by NASA and a number of engine manufacturers. Unfortunately, in the two decades that have passed since open rotor concepts were thoroughly investigated, NASA has lost experience and expertise in this technology area. This paper describes initial efforts to re-establish NASA s capability to assess aircraft designs with open rotor propulsion. Specifically, methodologies for aircraft-level sizing, performance analysis, and system-level noise analysis are described. Propulsion modeling techniques have been described in a previous paper. Initial results from application of these methods to an advanced single-aisle aircraft using open rotor engines based on historical blade designs are presented. These results indicate open rotor engines have the potential to provide large reductions in fuel consumption and emissions. Initial noise analysis indicates that current noise regulations can be met with old blade designs and modern, noiseoptimized blade designs are expected to result in even lower noise levels. Although an initial capability has been established and initial results obtained, additional development work is necessary to make NASA s open rotor system analysis capability on par with existing turbofan analysis capabilities.

Fuel consumption and emissions of ocean-going cargo ship with hybrid propulsion and different fuels over voyage

Abstract: Hybrid propulsion and using liquefied natural gas (LNG) as the alternative fuel have been applied on automobiles and some small ships, but research investigating the fuel consumption and emissions over the total voyage of ocean-going cargo ships with a hybrid propulsion and different fuels is limited. This paper tries to fill the knowledge gap by investigating the influence of the ship mission profile, propulsion modes and effects of different fuels on the fuel consumption and emissions of the ship over the whole voyage, including transit in open sea and manoeuvring in close-to-port areas. Results show that propulsion control and electric power generation modes have a notable influence on the ship's fuel consumption and emissions during the voyage. During close-to-port manoeuvres, propelling the ship in power-take-in (PTI) mode and generating the electric power by auxiliary engines rather than the main engine will reduce the local NOx and HC (hydrocarbons) emissions significantly. Sailing the ship on LNG will reduce the fuel consumption, CO2 and NOx emissions notably while producing higher HC emissions than traditional fuels. The hybridisation of the ship propulsion and using LNG together with ship voyage optimisation, considering the ship mission, ship operations and sea conditions, will improve the ship's fuel consumption and emissions over the whole voyage significantly.

Hybrid electric vehicle with limited operation strategy

Abstract: A hybrid electric vehicle 10 having a propulsion system 12 which includes an internal combustion engine 14, a generator/motor 16 and an electric motor or a “traction inverter module” 18 which cooperatively provide power to the drive train 28 of vehicle 10. Vehicle 10 includes a controller 44 which is effective to detect whether any faults are present within any of the torque providing subsystems (e.g., in engine 14, generator/motor 16 and/or motor 18), and if one or more faults is. present, to provide a limited operation strategy which allows the vehicle to be driveable by use of the remaining operational subsystem(s).

Electromagnetic and Structural Analysis for a Surface-Mounted PMSM Used for Light-EV

Abstract: This paper presents the performances of a surface-mounted permanent-magnet synchronous machine (SM-PMSM) from the electromagnetic and structural analysis point of view, which are evaluated numerically and through tests. The goal is to evaluate the possibility to use this SM-PMSM for the propulsion of a light-electric vehicle (L-EV), knowing that on one hand it has the best power density and, on the other hand, a torque wave with high ripples induces vibration and noise. This paper discusses the limits and the advantages for such a propulsion solution in order to evaluate its suitability for the L-EV applications.