Experimental investigation on initiation in main detonation chamber at ejector mode of a PDRE

To achieve the initiation in the main detonation chamber at the ejector mode of a pulse detonation rocket engine (PDRE), a model engine was designed using kerosene as fuel and oxygen as oxidizer. The model engine was designed and the peak pressure and the velocity of detonation waves were measured in the main detonation chamber utilizing piezoelectric sensors. The detonation was formed at a frequency ranging from 5 Hz to 8 Hz with a peak pressure of 3 MPa in the main detonation chamber, and propagated at a speed of 1600-2000 m/s. The experimental results indicate that the distance of DDT in the main detonation chamber at the ejector mode of a PDRE is much shorter than that in a conventional two-phase PDRE ignited by a spark plug. With the increase of frequency, it will be more difficult to achieve an ejector mode of PDRE. The ejector mode performance may be improved by increasing the length of the main detonation chamber and employing the convergent nozzle at the end of the ejector.