Evaluation of aerodynamic effects on pantograph contact force by means of Computational Fluid Dynamics

This paper discusses the possibility of using computational fluid dynamics (CFD) to assess the influence of aerodynamic forces on the mean contact force acting between a pantograph and the contact wire. The analysis consists of experimental tests and CFD simulations, performed in both wind tunnel and ontrack scenarios. A method for the computation of the aerodynamic uplift is proposed. The method is based on the virtual work principle, and exploits both the numerical forces resulting from CFD analysis, and the Jacobian terms obtained from a kinematic analysis of the pantograph. The proposed model takes into account stationary phenomena, and it is fully validated by means of experimental results. In particular, it demonstrates the possibility to extend, by means of CFD, the results obtained in a wind tunnel to the real scenario on the train roof.