Experimental study on the influence of rolling angle on aerodynamic characteristics of suspended monorail trains

Abstract

Compared with railway trains, crosswinds have a greater effect on the rolling angle behavior of suspended monorail trains (SMTs), which will inevitably change the aerodynamic configuration of the train-bridge system. This paper focuses on investigating the influence of rolling angle on aerodynamic characteristics of the SMT via pressure measurements in a wind tunnel. The surface pressure distribution, aerodynamic coefficient and admittance of the SMT model were analyzed over a wide range of rolling angle. The results indicate that the rolling angle has a certain influence on the surface pressure distribution of SMT, especially in the area near the corner of the windward surface. As the rolling angle increases, the absolute aerodynamic coefficients of lift force and moment will be reduced by 66% and 45%, while increasing percentage of side force coefficient is only 4.9%. Furthermore, a series of fitting formulas are proposed to estimate the aerodynamic coefficients of the train under different rolling angles based on the experimental data. The aerodynamic admittance functions of SMT show a peak value at a specific reduced frequency near 0.05, and the lift aerodynamic admittance is found to be sensitive to the rolling angle behavior of SMT in the reduced low-frequency range.