Propulsive performance of a liquid kerosene/oxygen pulse detonation rocket engine

Thrust and specific impulse are two critical parameters to estimate the performance of rocket engine. Utilizing liquid kerosene as the fuel, oxygen as oxidizer and nitrogen as purge gas, a series of multi-cycle detonation experiments were conducted to systemically investigate the relationships among the operating frequency, fill fraction and performance parameters of the pulse detonation rocket engine (PDRE). The operating frequency of PDRE was up to 49 Hz. The mass flow of liquid kerosene was measured by orifice meter and the mass flow of oxygen was measured based on the method of gas collection. The detonation chamber pressure traces were recorded by dynamic piezoelectric pressure transducers. A dynamic piezoelectric thrust transducer was used to record the instantaneous thrust produced by PDRE. Average thrust and detonative mixture-based specific impulse of PDRE with different operation frequency were obtained by experiments. The experimental results indicate that in the practical operation, the operating frequency caused the change of fill fraction, which resulted in a thrust enhancement. Due to the effect of fill fraction, average thrust did not linearly increase as the frequency rises. Fill fraction has a significant influence on the specific impulse of PDRE. The detonative mixture-based specific impulse presented a second order exponential decay with fill fraction, and was correspondingly increased with the raise of the operating frequency. With the strategy of partial filling in detonation tube, the specific impulse can be remarkably enhanced.