Utilization of Nonthermal Plasma in Pulse Detonation Engine Ignition

Abstract

Nonthermal plasma ignition using alternating-current-driven dielectric barrier discharge is applied to a pulse detonation engine. Five different geometrical in-house design plasma generators are tested to obtain more effective discharge performance. The selected plasma igniter, with 4.0 mm discharge gap between two electrodes with a dielectric barrier, can be powered by an alternating-current supply with output voltage and sinusoidal wave frequency. The required discharging waveforms, and hence ignition energy, can be obtained by the automatic frequency-control system, via which the operating frequency can be adjusted up to 500.0 Hz holding with almost unchanged breakdown voltages and currents in practical application. The respective mixture of hydrogen, acetylene, and ethylene was allocated with an excess air coefficient ranged from 0.6 to 1.4. The initial pressure of the mixture changed from 0.04 to 0.1 MPa and was tested in the single-trial experiments. The shortened deflagration-to-detonation transition and detonation waves show the effectiveness of nonthermal plasma-assisted ignition for wider excess air coefficients. The multicycle mode is also conducted to show the performance of 15.0 Hz collaborative operation using the plasma igniter in an airbreathing pulse detonation engine. The feasibility of the present alternating-current-driven dielectric barrier discharge technology to generate nonthermal plasma is thus verified for single-trial detonation tube and multicycle pulse detonation engine ignition in laboratory.