Determination of ignition thresholds of laser supported combustion wave and detonation wave based on piezoelectric probe

A new method of piezoelectric detection is presented for diagnosing ignition thresholds of LSCW and LSDW by measuring strain and stress, which generated on surface of target due to interaction between Nd:YAG laser operating at 1 064 nm and aluminum target. Changes of piezoelectric signal observed in experimental results might be divided into three stages, which can be explained as photothermal elastic strain, plasma enhanced coupling and LSDW pressure on the target surface in theory. Ignition thresholds of LSCW and LSDW can be determined by analyzing the shift of piezoelectric signal. Experimental results obtained are largely in accord with those from other methods. (authors)