基于三维、可压缩、非定常N S方程和kε双方程湍流模型,对不同斜切斜率帽檐斜切式洞门下的隧道空气动力效应进行数值模拟,得到高速列车过隧道时车体表面、隧道壁面监测点的瞬变压力及隧道出口微气压波。研究结果表明:帽檐斜切式隧道洞门的斜切斜率对车体表面和隧道壁面监测点的瞬变压力变化基本无影响,最大相差在5%左右;随着斜切斜率的减小,初始压缩波由零点上升到峰值所用时间减缓,压力梯度最大值减小;斜切斜率从1:1降至1:2时,隧道出口20 m处微气压波幅值由66 Pa降至54 Pa,降幅达18.2%,可见减小洞门结构的斜切斜率,可改善隧道口微气压波。数值计算结果与动模型试验结果吻合较好,仅幅值略有差异,最大相差在5%以下。
Based on three dimensional, unsteady N-S equation, influence on tunnel aerodynamic effects by oblique slope of hat oblique railway tunnel portal was simulated by the forms of numerical simulation, then micro-pressure and pressure changes of the train and tunnel were obtained. The results show that effects on the surface pressure changes of the tunnel and the train by oblique slope of hat oblique railway tunnel portal is little, and the maximum difference is about 5%; with the reduction of the oblique slope, time for the initial compression wave comes from zero up to a maximum peak becomes longer, so its largest pressure gradient becomes smaller; when oblique slope reduced from 1:1 down to 1:2, the micro-pressure waves on the place with the distance of 20 m from the tunnel exit is decreased from 66 Pa to 54 Pa, and the decrease amplitude is about 18.2%, so the reduction of the oblique slope can improve the tunnel micro-pressure waves. Results of numerical and dynamic model show good agreement, and the maximum difference is less than 5%.