Propulsion

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

Development of Methods for Analysis and Optimization of Complex Jet Engine Systems

Abstract: This thesis describes the development of GESTPAN (GEneral Stationary and Transient Propulsion ANalysis), a generalized system for the design, steady-state and transient simulation of gas turbine systems. Some of the main achievements in the thesis are related to the development of new algorithms or integration of existing numerics tailored to simplify the structure and use of generalized gas turbine simulation systems. In particular, a method for performing system design utilizing the analysis equations, i.e. an inverse design method, has been developed. Furthermore, attention is drawn to a number of advantages of using an implicit high order differential algebraic system solver for transient gas turbine system analysis. The simulation studies carried out with the GESTPAN system have focused on the performance optimization of the Selective Bleed variable cycle engine. In particular, a method for controlling the engine during mode transition was developed. Work with the implementation of a hybridized optimization method suitable for mission optimization of variable cycle engines is also described. The method couples the cycle selection and the control optimization of the engine variable geometry. Simulations performed with the method indicate that previously published designs of the Selective Bleed Variable cycle engine can be downsized considerably. Early work carried out in the research project concentrated on developing a method for optimizing the performance of variable geometry compressors integrated in gas turbine systems. Although the method was limited to subsonic operation of compressors, it was successfully used to simulate the core driven fan stage of the double bypass variable cycle engine.

Development of an Auxiliary Propulsion Module for an Autonomous Underwater Glider

Abstract: A low-power propeller-based propulsion module has been developed to augment the buoyancy engine of a 200 m Slocum electric glider. This device is introduced to allow new behaviours such as horizontal flight and faster overall speeds to expand the existing operational envelope of underwater gliders. The design of the system is optimized for use at the typical horizontal glider speed of 0.3 m/s. Before integration into the glider the stand-alone propulsion module has been tested in a small flume tank to verify the systems performance. The validity of a previously published hydrodynamic model of the glider at zero angle of attack was verified by conducting drag measurements at various flow velocities at full scale in a larger flume tank. Self-propulsion tests were also performed to establish the performance of the glider with the new propulsion module in the larger flume tank and in the university tow tank. The results from these tests show that the new propulsion module is able to match the performance of t...

Design and control of the induction motor propulsion of an Electric Vehicle

Abstract: This paper deals with a methodology for presizing the induction motor propulsion of an Electric Vehicle (EV). Based on the EV desired performances, the induction motor optimal power can be calculated. The final objective is to find its minimum weight, volume, and cost that meet the design constraints with minimum power under the European urban (ECE-15) and sub-urban (EUDC) driving cycles. The power presizing methodology is validated through extensive simulations for different induction motor-based EVs using a siding mode control technique.

Demonstration of a turbojet engine using an air foil bearing

Abstract: A test of the target drone main propulsion turbojet engine was recently conducted that demonstrated successful operation of a turbojet engine with a compliant foil air bearing. For this effort, the hot section rolling element bearing and the entire existing lubrication system was replaced with a compliant foil air bearing. This technology demonstration test showed the ability of the foil bearing to operate in the extremely challenging environment behind the turbine. Detailed engine integration studies, bearing component rig testing and hot engine simulator tests were completed prior to the successful engine test. The rig and simulator tests verified high temperature capabilities of the bearing and its surface coating, the bearing journal design, bearing dynamic performance, and rotor-bearing system dynamic stability, prior to engine integration and test. Based on these preliminary efforts, the engine and bearing were assembled and tests were conducted that included over 70 start stop cycles (including hot restarts), seven simulated mission cycles and more than 14 hours of run time. The foil bearing and engine operated flawlessly throughout the test. Vibrations were very low and all temperatures and pressures were as expected. A posttest tear down and hardware inspection revealed that the bearing, journal and all components remained in perfect condition. These data will be used to further the application of foil bearings to numerous other gas turbine engines for both military and commercial systems.Copyright © 2005 by ASME