Analysis of the Magnetohydrodynamic Energy Bypass Engine for High-Speed Airbreathing Propulsion


The performance of the magnetohydrodynamic (MHD) energy bypass airbreathing engine for high-speed propulsion is analyzed. The general relationship between performance and overall total pressure ratio through an engine is described. Engines with large total pressure decreases, regardless of cause, have exponentially decreasing performance. The ideal inverse engine is demonstrated to have a significant total pressure decrease which is cycle-driven, degrades with energy bypassed, and is independent of any irreversibility. The ideal MHD engine (inverse engine with no irreversibility except in MHD work interactions) is next examined and has an additional large total pressure decrease. Fundamental characteristics of MHD engine flows from the standpoint of irreversibility are examined. Severe constraints exist on allowable deceleration Mach numbers and required component volume due to both losses and flow choking. Last, thermally balanced engine simulations utilizing inlet shock systems, chemistry, wall cooling, fuel injection and mixing, friction, etc., are summarized for both the MHD engine and the conventional scramjet. The MHD bypass engine has significantly lower performance across the Mach number range (8-12.2) due to 1) additional irreversibility and cooling requirements associated with the MHD components and 2) total pressure decrease associated with the inverse cycle itself.


Mechanical and Aerospace Engineering

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Article - Journal

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© 2004 American Institute of Aeronautics and Astronautics (AIAA), All rights reserved.

Publication Date

01 Jan 2004