Numerical Simulation of Three Dimensional Transient Aerodynamic Characteristics of Two Crossing Vehicles

Abstract

The flow around the crossing vehicles is one kind of three-dimensional unsteady viscous incompressible flow. The finite volume method and the fully implicit scheme were adopted to discretize the Navier-Stokes equations of this flow in space and time, respectively, and the solving procedure of velocity and pressure in the flow field is based on PISO algorithm. The moving mesh strategy was presented to realize the relative movement of two vehicles with the time. The numerical simulation obtained the transient characteristics of aerodynamic force coefficients: the aerodynamic force coefficients vary abruptly and dramatically like a cosine curve at a certain period of time while vehicles are moving oppositely and crossing, and the coefficients of side force vary more severely, which deteriorates the moving stability of the high speed vehicles. The conclusions of the transient aerodynamic characteristics drawn from the simulation can provide references for the drivers or an intelligent driving system to properly steer and handle the vehicles in the crossing condition.