Influence of shaft on alleviating transient pressure in tunnel

Based on unsteady N-S equation of three-dimensional and compressible viscous fluid,transient pressure was simulated when a high-speed train passed by a tunnel with shaft.Time course and amplitude of transient pressure on the train were found.The results show that the calculated results agree with those of the experimental model.The switch of pressure curves attained by two methods are accorded completely,and amplitude merely presented difference is only about 5%,which indicates that simulation method applied is better to simulate aerodynamic effect when a high-speed train passes through a tunnel.Shaft can effectively reduce the transient pressure when a train runs through a tunnel,and pressure degradation of measuring point on the surface of middle car body is maximal,which reaches 31.2%.A assured tunnel in parameter has the best shaft location,number and section area that make alleviating effect best.