Based on the principle of hydraulics, an effective equipment of hydrodynarnic cavitation was designed and built. The orifice plates with various geometry size were used as hydrodynamic cavitation generator to study the relationship among, inlet pressure, discharge, flow speed in orifice,δ/d and the ratio of wetted cross-section area to cross section area and the cavitation number. Analysis of water flow cavitation status for the experimental unit, this device can produce cavitation phenomenon. The methylene blue and spectrophotometer method ca...