Abstract: RNG k-e turbulence model is applied to simulate the cavitating flow issued by the orifice flow of poppet valve. Experiments are conducted to catch cavitation images around the valve seat of the poppet valve from the perpendicular directions ，using a pair of industrial fiberscopes and high-speed video cameras integrated visualization system. The binary cavitating flow field distributions obtained from digital processing of original cavitation image show a good agreement with the numerical results. The results therefore indicate that RNG k-e turbulence model could achieve a reasonable prediction for the cavitating flow within the poppet valve as well as other hydraulic components. Besides， the vibrations of the valve body and poppet induced by the cavitating flow are detected using vortex displacement transducer，laser displacement meter and digital strain device.

Key words: Cavitation, Flow field simulation, Flow visualization, Poppet valve