Experimental investigation of multi-cycle pulse detonation engine at different air inlet systems

Abstract

To improve operation stability of pulse detonation engine and shorten the distance of deflagration to detonation transition, a series of multi-cycle detonation experiments were investigated with six different air inlet systems. Using air as oxidizer and liquid C8H18 as fuel, the effect of different air inlet systems on pulse detonation engine with frequency of 14 Hz and equivalence ratio of 1.5 was analyzed. Pressure history along detonation tube was recorded by five dynamic piezoelectric pressure transducers. It was approved by a particle image velocimetry that centrifugal forces from rotating airflow had a significant negative impact on the uniformity of fuel distribution in detonation tube. Furthermore, the experimental results indicated that operation stability of pulse detonation engine was increased with the improvement of fuel distribution, and deflagration to detonation transition distance was obviously decreased with the increase of thrust wall sealing. In these different air inlet systems, the pulse detonation engine with air inlet system of reed valve achieved the shortest deflagration to detonation transition distance, the best stability and stable operation of about 1 min at 14 Hz. This study provided references for the development of pulse detonation engine.