Research on the aerodynamic performance of bogies during high-speed train operation in tunnel

This study uses a three-dimensional, unsteady Navier–Stokes equation and a k − ϵ turbulence model to analyse the distribution of aerodynamic forces and torque on locomotives in tunnels, focusing on the impact of velocity. Findings reveal the highest positive pressure on the roof air conditioning from the windward side, while the bogie surface mainly exhibits negative pressure. However, areas like the axle end and windward side of the anti-hunting shock absorber, wheels, and brake discs show positive force. The pressure at the axle end of the bogie increases from the first to the sixth board. The peak force on the vehicle body and bogie decreases linearly with increasing velocity. During tunnel movement, the resistance of the first car is consistently higher than that of the other two cars, with similar resistance values among other bogies. The peak aerodynamic force curve varies quadratically with locomotive velocity. The first car experiences the highest aerodynamic torque, while the third car has the least. The aerodynamic moment amplitude of the sixth bogie is notably larger, increasing with velocity at a power exponent between 1 and 2. The aerodynamic torque of the bogie does not show regular changes with velocity variations.