| Nozzle is the core component of water jet technology. It is directly relatedto the efficiency of water jet. Self-excited oscillation pulsed nozzle servedas the study object, the paper discuss the influence of down nozzle shapeon self-excited oscillation pulsed jet by numerical simulation andexperimental research.The simulation of flow field in circular nozzle and square nozzle wascarried out by using CFD. It is analyzed the influence of structuralparameters on jet characteristics, and made a comparison of simulationresults. The simulation results indicated that compared with circularnozzle, the outlet velocity of square nozzle was higher, the attenuationamplitude of jet velocity was slower and the spread range of jet was morenarrow, so square nozzle had higher energy transmission efficiency andjet cluster property. Meanwhile it is tested a chamber pressure of circularnozzle and square nozzle, and conducted a erosion experiment of sandbrick. The experimental results showed that the pressure pulsed amplitudeincreased with the increase of chamber length, then decreased, increasedwith the increase of pump pressure; the pulsed amplitude of square nozzledecreased with the increase of nozzle area ratio; The pressure pulsed peakand pulsed amplitude in the chamber of square nozzle were greater thancircular nozzle under the appropriate parameters, so square nozzleenhanced the pulsed effect of jet; The erosion depth and volume of squarenozzle were larger than circular nozzle, so the erosin effect of squarenozzle was better; The simulation results were in agreement with theexperimental results. The research results have a guiding significance onself-excited oscillation pulsed jet in the engineering practice. |
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