Effect of convective cooling on frictionally excited thermoelastic instability

The effect of convective cooling on thermoelastic instability is evaluated using a finite element analysis. This is achieved by inserting a thermal convection term to the frictional heat generation in the formulation. It has been found that the convection or radiation heat dissipation can stabilize the thermal–mechanical feedback process, leading to a raised critical sliding velocity. Two representative models for brake and clutch systems are studied. The computational results reveal that the effect of thermal convection on the critical sliding speed is significant for liquid cooling (e.g. water, lubricants), but negligible for air convection. With the practical range of the convection coefficient estimated from the fundamental heat transfer theories, the critical speed in the presence of convection can be raised by two to three times as much as the original value. However, the wave number for the lowest critical speed remains almost unchanged regardless of the convective dissipation. The comparisons between linear and quadratic finite element interpolations are also made via a set of convergence studies. The results show that implementing quadratic elements in the friction layer has an obvious advantage over linear elements due to the rapid oscillations of the temperature across the thermal skin layer. This is particularly important in future studies when the problems in higher dimensions are of interest.