System Design Aspects of Propulsion Education in Aerospace Engineering Curricula

Abstract

In the present paper, the inadequacies of the traditional approach to undergraduate propulsion education are discussed. Propulsion as a system endeavor, in contrast to a single discipline, demands a system design education provided in a capstone engine design course in the senior year of aerospace engineering curricula. A suitable course content is proposed, and two examples of recent experiences at the University of Kansas with the AIAA National Airbreathing Engine Design competition are briefly presented. *Associate Professor; Member AIAA Brought to you by | University of Arizona Authenticated Download Date | 7/17/15 3:02 PM R Gas constant = R/MW SFC Specific fuel consumption TR Thrust reversing TV Thrust vectoring T ref Reference temperature = 520°R W Weight W K2 Corrected mass flow rate at compressor face Ξ M 2 /9 2 /6 2 X Semi-major axis of a bisuper ellipse (defined in Fig. 6) Y Semi-minor axis of a bisuper ellipse (defined in Fig. 6) Y M Ξ °MAX ~ d HL α Angle of attack ß Angle of spoiled sector for circumferential distortion π ά Inlet total pressure recovery •Θ--< Ratio of specific heats for a gas Average subsonic diffuser wall angle Brought to you by | University of Arizona Authenticated Download Date | 7/17/15 3:02 PMConventional Approach: Teaching Fundamentals Aerothermodynamic analysis of airbreathing engines constitutes the heart and soul of traditional undergraduate propulsion education. For this purpose, a brief review of thermodynamic principles applied to both a system and control volume is given in the first week of a propulsion course. Steady, one-dimensional flow of a perfect gas is then reviewed with applications to Rayleigh, Fanno, and shock flow. Cycle analysis and derivation of engine performance parameters mark the official beginning of a propulsion course. Here, cycle thermal and propulsive efficiencies and their respective limitations are discussed; and various airbreathing engine types, from turboprops to high-bypass-ratio turbofan engines, and from turbojets with reheat to conventional ramjets, find their suitable flight operating range. At this point, the students may be introduced to the performance gains obtained through concepts such as variable-cycle engines, counter-rotating advanced turboprops, and multimode hybrid propulsion. Cycle parametric investigation for the purpose of obtaining optimum solutions, both analytically and numerically, is advocated by Oates 11 ' 5 . It serves a very good purpose in that it provides deeper understanding and appreciation in students for widely differing requirements of low-and high-speed flight. Aircraft engine components analysis-i.e. inlets and nozzles, combustors and afterburners, and turbomachinery-then constitute the bulk of the propulsion course. The material continues into component matching and off-design analysis of airbreathing engines. At this point, the operational attractiveness and difficulties of implementation of a variable-area turbine (VAT) compared to conventional fixed-area turbine (FAT) could be appreciated by students Stre...

The Development of Rocketry Capability in New Zealand—World Record Rocket and First of Its Kind Rocketry Course

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