超高压水射流中空化现象对轮胎破碎作用研究

Cavitation Phenomena on Crushing Effect of Tire under Ultra-high Pressure Water Jet

为了探讨超高压水射流破碎轮胎过程中,冲击波和微射流的作用机理,基于FLUENT软件环境,采用VOF模型求解Navier-Stokes方程,数值模拟了近壁面的空泡溃灭过程,结果表明,射流冲击物面时,空泡溃灭产生的压力脉冲远大于微射流产生的冲击压力。结合超高压水射流破碎轮胎试验,通过对胎面胶的切槽断面形貌进行观察,研究了微射流和冲击波对橡胶材料的破坏作用,认为橡胶材料在受到空化作用破坏时,表现出明显的冲击脆化现象,微射流在材料壁面冲击出边缘齐整的针孔状形貌,冲击波引发材料产生拉伸破坏。

In order to study the failure mechanism of shock waves and micro jets in the fragmenta-tion process of tire under ultra-high pressure water jet impact,volume of fluid（VOF）model were used to solve the Navier-Stokes equation to simulate the bubble collapse process using FLUENT software. The results show that pressure pulses generated by bubble collapse is greater than the surge pressure caused by micro jets when the jet hits the tread rubber surface.Combined with the crushing tests of tire under ultra-high pressure water jet,grooving sections of tread rubber were observed using scan-ning electron microscope（SEM）to study the damage mechanism of the micro jets and shock waves.It is observed that rubber materials show obvious impact embrittlement phenomenon under the cavitati-on damage.Neat pinhole morphologies on the material surfaces are formed by the micro jets and ten-sile damage of the rubber material is caused by the shock waves.