Operational sensitivities of an integrated aerodynamic-ramp-injector/ gas-portfire flameholder in a supersonic combustor

Paper number

IAC-11,C4,5,5,x11005

Author

Dr. Baoxi Wei, Beihang University, China

Coauthor

Prof. Xu Xu, Beihang University, China

Coauthor

Mr. Minglei Yan, Beihang University, China

Coauthor

Dr. Xinxing Shi, Beihang University, China

Year

2011

Abstract

Results are presented of experiments conducted in a supersonic wind tunnel on an integrated fuel injection/ignition system, consisting of an aeroramp injector and a gas-portfire igniter. The main goals of the work were to determine how the lifting effect of the gas-portfire affected the fuel from aeroramp jet, to ascertain how the injection of gas through the gas-portfire influenced the combustion in the combustor model, and to investigate any synergistic effects from the combination. 
The gas-portfire igniter/flameholder was placed downstream of the injector on the centerline at three different locations in order to find the best suitable gas-portfire injector geometrical configurations.
The aeroramp was observed to generate a pair of streamwise vortex and gas-portfire had a strong lifting effect on this vortex. Experiments achieve a stable combustion while ethylene equivalence ratio above 0.1.As increasing the gas-portfire momentum flux ratio from 0.64~1.43, the delay time of ignition has been shortened obviously, but was not observed to influence the combustion efficiency. 3-D numerical study was conducted to investigate the details of combustion flow structures. The distribution of pressure obtained by experiments and simulation is according well (average error$<$5\%). The numerical results show that the distance of gas-portfire apart from aeroramp injector is a critical parameter which influenced the combustion efficiency. 
The results demonstrate that the gas-portfire play an important part in combustion enhancing. The ignition delay time is sensitive to momentum flux ratio of gas-portfire. When momentum flux ratio is lower than 1.0, the delay time will reach nearly 0.3s. On the other side, lower momentum flux ratio bring about a lower total pressure loss without drop of combustion efficiency, thus achieve a higher thrust.

Keywords: Aerodynamic-Ramp-Injector/Gas-portfire, Scramjet, Supersonic combustion.

Abstract document

IAC-11,C4,5,5,x11005.brief.pdf

Manuscript document

IAC-11,C4,5,5,x11005.pdf (🔒 authorized access only).

To get the manuscript, please contact IAF Secretariat.