Effect of height of noise barriers on sound source characteristics of aerodynamic noise from high-speed trains

• Noise barriers increase sound source intensity by 2.1–2.8 dB(A) for 400 km/h trains, with height-dependent effects varying along the train. • Thicker boundary layers near rear-middle and tail cars amplify crash wall influence, causing asymmetry and higher sound source intensity. • Higher barriers exacerbate flow asymmetry and sound source intensity due to deceleration/acceleration regions near the crash wall and barrier contraction. • DDES and FW-H coupling effectively captures barrier-induced aerodynamic noise mechanisms, aiding noise control design for high-speed rail.