Experimental study on aerodynamic characteristics of high-speed vehicles on bridges under crosswinds: a pseudo-moving method

Abstract

A novel pseudo-moving method is proposed to investigate the aerodynamic characteristics of high-speed vehicles on bridges subjected to crosswinds, aimed at overcoming the challenges associated with high force measurement noise and limited test duration typical of moving vehicle experiments. This pseudo-moving method employs a conventional wind tunnel for generating crosswinds, a longitudinal wind tunnel to simulate vehicle motion, and the relative motion system on bridge decks designed to eliminate ground effects. The validity of the test results obtained through the pseudo-moving method is confirmed by wind field characteristics and aerodynamic characteristics of vehicles. The results indicate that within the core region section, the longitudinal wind field exhibits a uniform wind speed distribution and low turbulence intensity. With the pseudo-moving method, larger crosswind induces longitudinal airflow deviation, reducing the core region length of the longitudinal airflow and resulting in a more restricted range of suitable wind yaw angles (β) for longer vehicles. The aerodynamic coefficients measured for the bus demonstrate trends consistent with those from the moving vehicle test. For β between 0° and 5°, the six-component coefficients of the CRH3 train show minimal variation; for β between 5° and 30°, the side force and moment coefficients increase steadily, while the drag and lift coefficients exhibit a trend inflection.