Effect of Bogie Fairing on Flow and Aerodynamic Noise Behaviour Around Bogie of HighSpeed Train

Abstract:

The influence of a bogie fairing on the aerodynamic and aeroacoustic behaviour of flow past a simplified highspeed train bogie located in a bogie cavity at a scale of 1∶10 was studied using a twostage hybrid method comprising computational fluid dynamics and acoustic analogy. The nearfield unsteady flow was obtained by solving the NavierStokes equations numerically with the delayed detachededdy model and the results are used to calculate the farfield noise through a noise prediction code based on the convective Ffowcs WilliamsHawkings method. It is found that due to the surface shape discontinuity in the bogie cavity along the carbody side and bottom walls, a highly turbulent flow is generated within the bogie cavity. The vortices formed behind the upstream geometries are convected downstream and impinge on the downstream bodies, generating a highly turbulent wake behind the bogie. When the fairing is mounted around the bogie cavity, the interaction between the flow and the bogie cavity is reduced. The results show that the bogie fairing is effective in reducing the noise generated in most of the frequency range for the current model case based on predictions of the noise radiated to the trackside using a permeable data surface close to the bogie and parallel to the carbody side wall.

Key words:railway noise; simplified train bogie; bogie fairing; aerodynamic noise prediction; flow behavior