Abstract

The dynamic hydroplaning of a deformable automobile tire is calculated. The three‐dimensional flow around the tire is described by an efficient free surface model and the Navier‐Stokes equations. The effects of turbulence are modeled by the well‐known k,ε‐model. The deformation of the tire is calculated using a noncommercial finite element program, in which all components of the three‐dimensional tire are taken into account with their own mechanical and constitutive behavior. The deformation of the tire during stationary hydroplaning is found by an iterative solution procedure. The result of the calculation is the pressure distribution and the velocity field. The integration of the pressure distribution acting on the tire surface yields the lift and drag forces as well as lift and drag coefficients. The calculations are performed for a smooth‐shaped tire at speeds of 30, 60, and 90 km/h driving speed and an 8 mm high water film. The results are compared with those of the undeformable tire. The calculated pressure distribution on the pavement shows very good agreement with experimentally obtained data. At 90 km/h the model predicts that the water penetrates the contact area of the tire whereas the tire still has contact with the road in the shoulder area. This is also found in experiments. Further, calculations are performed for a deformable tire with three circumferential grooves. Here the influence of different water depths at a speed of 90 km/h is investigated. The groove depth of the tire is 8 mm whereas the water depth varies between 4, 8, and 12 mm. The calculations show the intrusion of a water wedge into the contact area. As in previous studies it is found that the tire deformation has a very strong influence on the resulting lift forces.