Experimental study of the effect of kerosene combustion on the shock train location in a scramjet combustor

A series of kerosene combustion experiments was carried out on the combustion test equipment of Northwestern Polytechnical University to study the effect of fuel supply control schemes on the shock train location, and the feasibility of controlling the shock train location by changing fuel supply was studied. Five different fuel supply schemes were used in the test to compare which scheme can obtain a stable shock train location. The shock train leading-edge location was detected by the change of wall pressure in the isolator, then the relation between the fuel supply and the shock train location was analyzed. The test results showed that: (1) when different fuel supply schemes were used, the change speed and stability of the shock train leading-edge location in the isolator were different; (2) to control the shock train leading-edge location, choosing the combustor wall pressure, or the isolator inlet and outlet pressure ratio as the controlled parameters is feasible; (3)the closed-loop fuel supply scheme which using the wall pressure at the outlet of the isolator as the controlled parameters, can obtain a relatively stable shock train leading-edge location; (4) in the closed-loop control test of two-point oil supply, the experimental purpose of increasing the wall pressure distribution in the expansion section of the combustor without changing the wall pressure distribution in the isolator was realized, which is beneficial to improving the engine performance.

Automated summary

A series of combustion experiments with kerosene were conducted at Northwestern Polytechnical University's combustion test equipment to investigate the impact of fuel supply control schemes on the location of shock trains. The feasibility of controlling shock train locations by altering fuel supply was also explored. Results showed that different fuel supply schemes resulted in varying speeds and stability of the shock train location. Choosing the combustion chamber wall pressure or the isolator inlet and outlet pressure ratio as controlled parameters was found to be effective in controlling shock train locations, and a closed-loop fuel supply scheme using isolator outlet wall pressure as a controlled parameter achieved a relatively stable shock train location. Additionally, a closed-loop control test with two-point oil supply successfully increased the wall pressure distribution in the combustion chamber expansion section without altering the isolator's wall pressure distribution, which is beneficial for improving engine performance.