TY - JOUR
T1 - Mixing characteristics of inclined fuel injection via various geometries for upstream-fuel-injected scramjets
AU - Ogawa, Hideaki
N1 - Funding Information:
The author wishes to acknowledge the support of the Australian Research Council through the Discovery Early Career Researcher Award grant no. DE120102277. The author is also grateful to R. R. Boyce at the University of New South Wales, Canberra, for providing advice and resources in this research project during the appointments at the Centre for Hypersonics, the University of Queensland.
Publisher Copyright:
© 2015 by Hideaki Ogawa. Published by the American Institute of Aeronautics and Astronautics, Inc., with permission.
Copyright:
Copyright 2020 Elsevier B.V., All rights reserved.
PY - 2015
Y1 - 2015
N2 - Efficient fuel/air mixing plays a crucial role in successful operation of hypersonic airbreathing engines, particularly scramjets, where fuel must be injected into high-speed crossflow and mixed with air at an extremely short timescale. This paper presents the results of a numerical study that investigates the effects of various orifice shapes on fuel mixing characteristics into hypersonic airflow at Mach 5, aiming at the application to scramjet operation with upstream fuel injection at Mach 10. The performance of the injectors at an inclination angle of 45 deg are assessed with respect to various criteria such as the mixing efficiency, streamwise circulation, total pressure recovery, fuel penetration, and spread. Streamwise slot injectors have been found to yield higher mixing efficiency than the other injectors tested (namely, square, circular, diamond, and triangular injectors), owing to the buffering effects. Apparent higher total pressure recovery has been obtained with these rectangular injectors, but their advantages have diminished significantly with the alignment of the trailing-edge position. The highest vertical penetration has been achieved by the square injector, whereas the performances of other injectors with a sharp leading edge have been found to be affected considerably by the axis switch phenomenon due to inclined injection at higher injection pressure. A major influence of the fore and aft shapes of the orifice has been observed on the three-dimensional bow shock formation and wake recirculation, respectively.
AB - Efficient fuel/air mixing plays a crucial role in successful operation of hypersonic airbreathing engines, particularly scramjets, where fuel must be injected into high-speed crossflow and mixed with air at an extremely short timescale. This paper presents the results of a numerical study that investigates the effects of various orifice shapes on fuel mixing characteristics into hypersonic airflow at Mach 5, aiming at the application to scramjet operation with upstream fuel injection at Mach 10. The performance of the injectors at an inclination angle of 45 deg are assessed with respect to various criteria such as the mixing efficiency, streamwise circulation, total pressure recovery, fuel penetration, and spread. Streamwise slot injectors have been found to yield higher mixing efficiency than the other injectors tested (namely, square, circular, diamond, and triangular injectors), owing to the buffering effects. Apparent higher total pressure recovery has been obtained with these rectangular injectors, but their advantages have diminished significantly with the alignment of the trailing-edge position. The highest vertical penetration has been achieved by the square injector, whereas the performances of other injectors with a sharp leading edge have been found to be affected considerably by the axis switch phenomenon due to inclined injection at higher injection pressure. A major influence of the fore and aft shapes of the orifice has been observed on the three-dimensional bow shock formation and wake recirculation, respectively.
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U2 - 10.2514/1.B35581
DO - 10.2514/1.B35581
M3 - Article
AN - SCOPUS:84946849796
VL - 31
SP - 1551
EP - 1566
JO - Journal of Propulsion and Power
JF - Journal of Propulsion and Power
SN - 0748-4658
IS - 6
ER -