Clutch transient heat transfer simulation for hill start vehicle test condition

Abstract

The successive repetitive engagement operation causes temperature rise on the friction surfaces of the automotive dry clutches. This condition is simulated via hill start vehicle tests by clutch manufacturers during thermal performance validation of new transmission platforms or vehicle configurations. The aim of this study is to determine the temperature variation of the clutch pressure plate by the use of a 1D transient thermal simulation for the hill start vehicle test conditions. Simulation model includes pressure plate, flywheel and clutch housing elements. Clutch housing air temperature variation was simulated numerically for 120 successive repetitive cycles of hill start truck vehicle test. Parameters effecting pressure plate temperature change were analyzed. It is observed that increasing the mass of the clutch pressure plate results a decrease in the temperature variation in early stages of engagement cycles. However, increasing the value of the pressure plate convection coefficient significantly reduces the temperature variation during all stages of cycles. Finally, lightweight design proposals of dry clutch pressure plate for better energy dissipation are demonstrated.