Hydrodynamics and Friction Estimation for Wet Tire/Ground Interactions

Understanding wet tire/road interactions is critical for predicting unstable operating conditions such as hydroplaning and for vehicle safety operation. We present an analytical method to compute water film pressure and thickness distributions on the viscous hydrodynamic region between the tire and the ground. The hydrodynamic models and analysis are obtained for the smooth tire surface and tires with transverse tread elements. We present analytical conditions to predict the hydroplaning occurrence. The impact of wet condition on tire/ground friction forces is also discussed through the effective length of the contact patch and a LuGre friction model. Simulation results are presented to demonstrate the modeling development. Comparisons with other existing models illustrate the advantage of the proposed models and analysis.