Combustion characteristic using O₂-pilot strut in a liquid-kerosene-fueled strut-based dual-mode scramjet

Abstract

A set of exploratory experiments are conducted to test a newly designed strut for fuel injection and flame holding in a liquid-kerosene-fueled dual-mode scramjet combustor. The thickness of the strut is 8 mm and the front blockage is about 8%. To organize stable combustion in a Mach number equal to 2.6 air flow under this thin strut using room-temperature liquid kerosene in a flash wall combustor without any cavity and other flame holders, some oxygen is injected through a set of orifices at the back of the strut, based on which a stable center local flame is generated at the back of the strut and the main flow combustion can be organized around this local flame. Experimental results show that stable combustion can be achieved at the center of the combustor with a wide range of equivalence ratio from 0.19 to 1 based on this center flame strut strategy. Through the analysis of the pressure distribution along the combustor, different combustor modes appear with different equivalence ratio. The article also gives some discussions about different influence of the oxygen to the combustion process under different equivalence ratio.

Effects of upstream strut on the combustion of liquid kerosene in a model cavity scramjet

“…The experiments were conducted in the direct-connected scramjet test system 15 at the Institute of Advanced Power in HIT, China. In the experiments, the compressed air is heated by alcohol combustion to the condition with a total pressure and temperature of 2.1 MPa and 1500 K, respectively, and additional oxygen is added to keep the oxygen concentration equal to the value in the atmosphere.…”

Survey on the mode transition technique in combined cycle propulsion systems

“…The transition equivalence ratio varies from 0.17 to 0.22 in the range of 1000-1500 K for the inlet stagnation temperature, and the area ratio of the combustor geometry and the heat losses to the walls have a great impact on the transition values as well. Bao et al [1] have also found that different combustor modes occur with different equivalence ratio through the analysis of the pressure distribution along the combustor. Masumoto et al [42] have successfully proposed a simple model to predict the minimum combustor length for the supersonic or dualmode combustion, and four operating modes have been observed, namely non-ignition, weak, supersonic and dual-mode combustion [27,28].…”

Experimental and computational study on combustion performance of a kerosene fueled dual-mode scramjet engine

“…3 PhD. 4 Associate researcher. bustion mode, the ignition and combustion of fuel occurred within the boundary layer in the combustor.…”

“…Firstly, the flush wall supersonic combustor equipped with center strut flameholding was studied experimentally by Refs. [4][5][6][7][8] in contrast with the cavity [4,5], and the fuel injection strategy between the strut and the wall was conducted by experiment [6], and the effects of upstream strut on the combustion of liquid kerosene in a model cavity scramjet was discussed [7,8]. For the novel supersonic combustor with flush wall, the combustion mode transformation characteristic needs to be investigated deeply.…”