Abstract: Aiming at the high vaporous pressure and easy cavitation occurrence of water, the cavitation flow in orifices using water as working media is analysed theoreticalIy by applying cavitation model. At the same time, the cavitation flow in the orifices is experimented with visualization method. Based on these, the growing processes of cavitation in the orifices are introduced and the influences of diameter and the ratio of length and diameter of orifices are analysed. The research results show that cavitation occurs firstly at the inlet of orifice and is gradually pushed to the outlet with the increasing of pressure drop across the orifice. Cavitation is more likely to happen in the orifice with larger ratio of length and diameter when the diameter is the same and with larger diameter when the ratio of length and diameter is the same.

Key words: Cavitation flow, Cavitation model, Orifice, Water hydraulic transmission