锥阀阀口气穴流场的数值模拟与试验研究

NUMERICAL AND EXPERIMENTAL IN-VESTIGATION OF CAVITATING FLOW WITHIN HYDRAULIC POPPET VALVE

采用NNGk-ε湍流模型数值模拟了锥阀阀口的气穴流动。运用工业纤维镜与高速摄像机等组成流场可视化试验系统,多方位地观察了阀口附近的气穴现象,对其进行数字图像处理后,获得了气穴流场的分布信息,与仿真结果比较,吻合良好,表明RNGk-ε湍流模型能有效地描述锥阀等液压元件的阀口气穴流动。同时采用涡流式位移传感器、激光位移器和数字应变测量仪等构成的检测系统,研究了气穴流场诱发的阀体与阀芯振动。

RNG k-ε 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 highspeed 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-ε 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.