Field study on train-induced aerodynamic pressure near the entrance of fully enclosed sound barriers

Abstract

A systematic field test was conducted for aerodynamic pressure near the entrance of the double-track fully enclosed sound barriers (FESBs). The generating mechanism of pressure was revealed by referring to the slipstream distribution around the moving train and considering the influence of marshalling length, speed and streamline of trains. Results show that near the entrance, the compression wave caused by the head car is predominant and determined by the maximum, minimum and peak-to-peak pressure, while near the exit, the negative and positive peak pressure are, respectively, triggered by the head car and tail car. Uneven pressure distribution along the circumference of the FESB wall and the greater pressure is on the wall near the running train. The head car of double-connection electric multiple units (EMUs) generates greater pressure near the entrance than that of common EMUs, and the tail car of double-connection EMUs causes weaker pressure transient, while near the exit, the head car of double-connection EMU induces weaker pressure. Even if the train speed increases in a small range, the pressure near the entrance/exit of the FESB increases, and the blunter the train is, the greater and the more evenly distributed pressure on the FESB will be.