Experiments On The Stability Of Car Models In The Flood Water

With the rapid development of the manufacture and other industries, urbanization process is getting faster and faster, and car ownership of urban residents has increasing year by year. Along with this rapid development, the global climate warming has becoming intensified, the urban floodings caused by the sudden extreme rainstorms occur frequently, which causes lots of cars submerged in the flooding water, or losing its stability by floating or slipping. Sometimes peoples drowned in the car during those extreme events. So it is of great practical significance to do research on the instability of the cars in the flooding flow.This paper has carried out the following research:1. In a rectangular tank, floating tests of Santana, Cadillac SLS and Volkswagen Touareg SUV, which are completely sealed or completely open to water, have been conducted. The buoyancy forces of cars have been measured. Considering with the vehicle features, the floating depth of vehicles have been computed and compared. At the same time, some suggestions for safe escaping from the submerged cars in a deep water has been recommended.2. In a testing flume, experiments have been done to measure the drag forces of water past the models of Cadillac SLS and Volkswagen Touareg SUV with the front of car models or the rears towards the approaching water flow at different flume slopes and different water depths. At the same time, the flow field around the car models on a flat flume were recorded by a high speed camera.3. Based on the measured, the effective drag force coefficients of flow around car on a sloping flume has been calculated and analyzed by combining the flow field around the car. A formula to compute the critical velocity of water when car slips in a sloping fume was proposed based on the force measurement principle, with which the critical flow velocities for Cadillac SLS and Volkswagen Touareg SUV were calculated and discussed.