高速列车致声屏障风压变化和分布特性研究

Wind Pressure Changes and Distribution of Sound Barrier Caused by High-Speed Train

高速列车致声屏障在极短的时间内受到交变气动力作用,一旦声屏障因强度或疲劳破坏而失效,有可能危及行车安全,因此准确评估高速列车致声屏障的脉动风压分布是结构设计需考虑的关键要素.利用数值风洞技术,模拟了道路及桥梁两侧分别布置5m、3.5m高声屏障,350km/h的列车通过时致声屏障的极值风压分布特性.研究结果表明列车驶过声屏障会产生气流挤压的正压波及气流填充的负压波,正压数值较负压数值大;极值风压随声屏障高度的增加而减小,且列车中心与声屏障的距离、声屏障的高度都会明显减弱极值风压的数值;两列车的交会相比单列车的通过,会更明显地挤压声屏障区域内的气流,从而在声屏障上产生更大的极值风压,且随着列车与声屏障距离的靠近,挤压增大极值风压的特性表现更为明显.最终通过选取京沪高铁试验段,进行相关的现场高速列车致声屏障极值风压试验测试,试验结果验证了数值模拟结果的准确性.

Sound barrier caused by high-speed train alternating aerodynamic effect in a very short period of time, once the sound barrier due to the strength or fatigue damage and failure, is likely to endanger traffic safety, so an accurate assessment of the sound barrier pulsating pressure distribution caused by high-speed train is the key elements of the design considerations. Numerical wind tunnel technology to simulate the road and bridges are arranged on both sides of 5m, 3.5m sound barrier, when the sound barrier fluctuating pressure distribution caused by the train with the speed 350km / h. The rearch results show that the train passing the sound barrier would produce positive pressure wave airflow and airflow squeeze filled negative pressure wave, positive values representing a large negative value; Simply repeating the pulsating pressure decreases the barrier height increases, and the distance between the center and the train sound barrier, sound barrier height will be significantly weakened the value of the pulsating pressure; Compared to the two train traffic through a single train, will be more apparent squeeze sound barrier airflow within the region, resulting in greater pressure on the pulsating sound barrier; and with the train and the sound barrier near distance, squeeze increasing the pressure pulsation characteristics more obvious. Beijing-Shanghai high-speed rail by selecting the final test section, the associated sound barrier caused by high-speed train scene pulsating pressure test test test results to verify the accuracy of the numerical simulation results.