冲蚀磨损与冲蚀、空蚀交互磨损的对比研究

A Comparative Study Between Erosive Wears and Interactive Wears

基于计算流体力学(computational fluid dynamics,CFD)方法,数值对比研究了在模拟水轮机工况中不同转速时,冲蚀与冲蚀、空蚀交互作用时,转盘表面的流场(压力场、流体浓度分布),然后在转盘式磨损装置上,进行了汽液固三相冲蚀与空蚀交互磨损试验.结果表明:对于冲蚀磨损来说,随着转速增加,压力增大,在冲蚀作用下加入空蚀磨损,压力增高,磨损加剧;而对于交互磨损来说,随着转速增加,转盘表面的空蚀磨损区域从空化孔附近开始沿着转盘旋转的反方向偏移,并且磨损程度加剧;数值计算的气泡较多且压力梯度较高区域和试验转盘磨损区域基本一致,数值计算结果和试验结果吻合得较好.

Based on the computational fluid dynamics （CFD） method, simulating the working conditions of hydraulic turbine in different rotating speeds, the flow fields （pressure field and fluid concentration distribution） on the rotary table surface are numerically compared under erosive wears and interactive wears. On the rotating wearing experimental device, the interactive erosion and cavitation wearing experiment of three phases are done. The results show that in the process of the erosive wear, when the rotating speed is increased, the pressure is increased. And if the cavitation damage is added, the pressure is further increased and wear is markedly increased. In the process of the interactive wear, the pressure is increased, the cavitation damage region on the rotary table surface moves in the reverse direction from the neighboring region of the cavitation hole, and wear is markedly increased. Numerical simulative air - bubble tracks on the high pressure gradient region are in agreement with the wear scars, and the experimental results and theoretical results are in good agreement.