Impact of inclined porous media hoods on micro-pressure waves induced by high-speed maglev trains traversing tunnels

Abstract

The high-speed maglev train traversing tunnels will cause noise pollution to the surrounding environment. Utilizing inclined porous media hoods (IPMHs) is an effective solution for mitigating micro-pressure waves (MPWs). This study employs an improved delayed detached eddy simulation turbulence model and overset technique to simulate the aerodynamic effects of maglev trains passing through tunnels. The reliability of the numerical method is validated through moving-model experimental data. The study investigates the influence of IPMH slope and location on wavefront characteristics and MPW evolution. The peak cut principle of the entrance IPMH and the exit pressure relief on the MPW amplitude are discussed. The research results indicate that the entrance IPMH achieves the effects of extending the wavefront rise time and achieving balance in the multi-peak wavefront gradient. The exit IPMH can regulate the balance between pressure relief amplitude and MPW amplitude by controlling its slope. IPMH causes the MPW profile to undergo three evolutionary stages: semi-frustum, semi-gourd shape, and semi-ellipsoid. Reducing the IPMH slope benefits increasing the solid radiation angle to facilitate pressure relief. The mitigation rates of MPW amplitude achieved by the entrance, exit, and side IPMHs are 52.2 %, 70.0 %, and 86.1 % respectively. The findings offer valuable references for the design of high-speed maglev tunnel hoods.