Experimental Investigations of a Pulsed Detonation Combustor-Turbine Hybrid System

Abstract

Experimental studies were performed to investigate the interactions of a pulse detonation engine (PDE) tube integrated with a radial flow turbine of a turbo-charger and to examine whether a compressor and turbine could be used in the harsh pulsing flow of a pulse detonation engine. The effect of equivalence ratio on the attenuation of the peak pressure exiting pulse detonation combustor (PDC) through a turbine was also investigated. Liquid C8H16 and air were used as the fuel and oxidizer. The experimental rig can be operated stably under the firing frequency with a range from 1 to 10 Hz. The fully developed detonations are propagating directly into the turbine inlet and yet the turbine still functions despite over 12,000 detonations, showing no visible pitting or discoloration. The air mass flow rate at the exit of the compressor is about 100 kg/h greater than that at the inlet of PDC. The peak pressure exiting PDC firstly increases and then decreases with increasing equivalence ratio from 0.86 to 1.27. The maximum peak pressure exiting PDC is achieved at an equivalence ratio of 1.15. The turbine attenuates the strength of detonation driven shocks about 6.5-7.5 dB. But the attenuation trend is opposite to that of peak pressure.