Analysis on frequency characteristics of self-excited oscillation pulsed nozzle

摘要

In order to probe the feasibility of square nozzle as a generating device of self-excited oscillation pulsed water jet, experiments were conducted with two kinds of self-excited oscillation pulsed nozzle in air by using the self developed device. The effect of structure parameters of nozzles and working pressure on the oscillation frequency of jet was investigated, and the cavity pressure was measured by CavTest test system. The obtained data showed that negative pressure appeared both in two nozzles, the peak values of pressure increased with increasing cavity length, whereas the pulse amplitude increased at first, then decreased with increasing cavity length. There was an optimum length of cavity corresponding to the most intensive pulse amplitude. Moreover, the pulse effect of non-circle nozzle was superior to circle nozzle.