scispace - formally typeset
Search or ask a question
Topic

Propulsion

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


Papers
More filters
Proceedings ArticleDOI
05 Mar 1995
TL;DR: In this article, the authors present methods and results of a prototype switched reluctance (SR) motor design study, which predicts performance, efficiency, and weight that are competitive with existing EV propulsion systems, which have been tested in compact automobiles and small trucks.
Abstract: Low cost, high reliability, and competitive weight and efficiency combine to make the switched reluctance (SR) motor drive a strong candidate for application in future electric vehicle (EV) propulsion systems. This paper presents methods and results of a prototype SR motor design study. Finite element analysis and transient simulation results predict performance, efficiency, and weight that are competitive with existing EV propulsion systems, which have been tested in compact automobiles and small trucks. >

48 citations

Proceedings ArticleDOI
01 Jan 1980
TL;DR: A scale model performance test was conducted as part of the NASA Energy Efficient Engine (E3) Program, to investigate the geometric variables that influence the aerodynamic design of exhaust system mixers for high-bypass, mixed-flow engines as discussed by the authors.
Abstract: A scale model performance test was conducted as part of the NASA Energy Efficient Engine (E3) Program, to investigate the geometric variables that influence the aerodynamic design of exhaust system mixers for high-bypass, mixed-flow engines. Mixer configuration variables included lobe number, penetration and perimeter, as well as several cutback mixer geometries. Mixing effectiveness and mixer pressure loss were determined using measured thrust and nozzle exit total pressure and temperature surveys. Results provide a data base to aid the analysis and design development of the E3 mixed-flow exhaust system.

48 citations

Journal ArticleDOI
TL;DR: In this paper, the authors classified electric thrusters in accordance with the mechanism by which they induce thrust as electrothermal, electromagnetic, and electrostatic, and considered the characteristics of plasmas in electric propulsion systems along these lines.
Abstract: Electric thrusters offer the promise of a substantial improvement in performance over that of conventional chemical rockets currently used in space propulsion applications. There are three basically different ways in which electrical power and propellant inputs might be combined to produce thrust: (1) propellant can be heated electrically and then expanded through a nozzle; (2) electromagnetic body forces can be applied to accelerate a plasma to the desired exhaust velocity; or (3) electrostatic body forces can be applied to accelerate charged particles. Electric thrusters are classified in accordance with the mechanism by which they induce thrust as electrothermal, electromagnetic, and electrostatic. The characteristics of plasmas in electric thrusters along these lines are considered. >

48 citations

Proceedings Article
16 Jun 2014
TL;DR: The first ever full scale, high altitude ice crystal cloud turbofan engine test to be conducted in a ground-based facility was conducted by the Propulsion Systems Laboratory (PSL) as mentioned in this paper.
Abstract: The Propulsion Systems Laboratory (PSL) is an existing altitude simulation jet engine test facility located at NASA Glenn Research Center in Cleveland, OH It was modified in 2012 with the integration of an ice crystal cloud generation system This paper documents the inaugural ice crystal cloud test in PSL--the first ever full scale, high altitude ice crystal cloud turbofan engine test to be conducted in a ground based facility The test article was a Lycoming ALF502-R5 high bypass turbofan engine, serial number LF01 The objectives of the test were to validate the PSL ice crystal cloud calibration and engine testing methodologies by demonstrating the capability to calibrate and duplicate known flight test events that occurred on the same LF01 engine and to generate engine data to support fundamental and computational research to investigate and better understand the physics of ice crystal icing in a turbofan engine environment while duplicating known revenue service events and conducting test points while varying facility and engine parameters During PSL calibration testing it was discovered than heated probes installed through tunnel sidewalls experienced ice buildup aft of their location due to ice crystals impinging upon them, melting and running back Filtered city water was used in the cloud generation nozzle system to provide ice crystal nucleation sites This resulted in mineralization forming on flow path hardware that led to a chronic degradation of performance during the month long test Lacking internal flow path cameras, the response of thermocouples along the flow path was interpreted as ice building up Using this interpretation, a strong correlation between total water content (TWC) and a weaker correlation between median volumetric diameter (MVD) of the ice crystal cloud and the rate of ice buildup along the instrumented flow path was identified For this test article the engine anti-ice system was required to be turned on before ice crystal icing would occur The ice crystal icing event, an uncommanded reduction in thrust, was able to be turned on and off by manipulating cloud TWC A flight test point where no ice crystal icing event occurred was also duplicated in PSL Physics based computational tools were successfully used to predict tunnel settings to induce ice buildup along the low pressure compression system flow path for several test points at incrementally lower altitudes, demonstrating that development of ice crystal icing scaling laws is potentially feasible Analysis of PSL test data showed that uncommanded reduction in thrust occurs during ice crystal cloud on operation prior to fan speed reduction This supports previous findings that the reduction of thrust for this test article is due to ice buildup leading to a restricted airflow from either physical or aerodynamic blockage in the engine core flow path

48 citations

01 Jan 2009
TL;DR: In this paper, the authors used an Artificial Neural Network (ANN) to predict the propulsion power with accuracy between 0.8-1.7% using onboard measurement system data and 7% from manually acquired noon reports.
Abstract: Full scale measurements of the propulsion power, ship speed, wind speed and direction, sea and air temperature from four different loading conditions, together with hind cast data of wind and sea properties; and noon report data has been used to train an Artificial Neural Network for prediction of propulsion power. The model was optimized using a double cross validation procedure. The network was able to predict the propulsion power with accuracy between 0.8-1.7% using onboard measurement system data and 7% from manually acquired noon reports.

48 citations


Network Information
Related Topics (5)
Control system
129K papers, 1.5M citations
79% related
Control theory
299.6K papers, 3.1M citations
77% related
Reynolds number
68.4K papers, 1.6M citations
77% related
Turbulence
112.1K papers, 2.7M citations
76% related
Optimal control
68K papers, 1.2M citations
75% related
Performance
Metrics
No. of papers in the topic in previous years
YearPapers
20231,085
20222,061
2021739
20201,050
20191,194
20181,187