Thermodynamic Analysis of Dual-Mode Scramjet Engine Operation and Performance


Recent analytical advances in understanding the performance continuum (the thermodynamic spectrum) for air-breathing engines based on fundamental second-law considerations have clarified scramjet and ramjet operation, performance, and characteristics. Second-law based analysis is extended specifically in this work to clarify and describe the performance characteristics for dual-mode scramjet operation in the mid-speed range of flight Mach 4 to 7. This is done by a fundamental investigation of the complex but predictable interplay between heat release and irreversibilities in such an engine; results demonstrate the flow and performance character of the dual mode regime and of dual mode transition behavior. Both analytical and computational (multi-dimensional CFD) studies of sample dual-mode flow-fields are performed in order to demonstrate the second-law capability and performance and operability issues. The impact of the dual-mode regime is found to be characterized by decreasing overall irreversibility with increasing heat release at a given flight Mach number, within the operability limits of the system.

Meeting Name

14th AIAA/AHI Space Planes and Hypersonic Systems and Technologies Conference (2006: Nov. 6-9, Canberra, Australia)


Mechanical and Aerospace Engineering

Keywords and Phrases

Performance Continuum; Ramjet; Scramjet; Thermodynamic Spectrum

Document Type

Article - Conference proceedings

Document Version


File Type





© 2006 American Institute of Aeronautics and Astronautics (AIAA), All rights reserved.

Publication Date

09 Nov 2006

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