Analysis on thermal effect on high-speed wheel/rail adhesion under interfacial contamination using a three-dimensional model with surface roughness

A three-dimensional numerical model of wheel/rail in rolling contact is established to study the adhesion characteristics under interfacial contamination considering surface roughness at high speed. The thermal partial elastohydrodynamic lubrication (EHL) theory in elliptical contact is used in the model. The numerical model is successfully solved by applying the iterative algorithm between the pressure field and temperature field. Multilevel method is used to solve modified Reynolds equation. Sweeping column method is used to solve energy and heat conduction equations. The effects of train speed, surface roughness amplitudes, roughness orientation and axle load on the adhesion coefficient under interfacial contamination are numerically investigated. A typical creepage-traction curve under oil contamination is obtained at high speed by the present model. In addition, the effects of temperature and the elastic-plastic deformation behaviour of asperities on the adhesion coefficient are discussed in the paper. Furthermore, the effect of different interfacial contaminations on wheel/rail adhesion using the present model on the adhesion coefficient is investigated. In order to validate the present model, the numerical results are compared with the experimental results that were obtained by JD-2 high-speed wheel/rail rolling contact machine under water/oil contaminations.