中文摘要：

高速列车以大于300 km/h的速度穿越隧道时,在隧道出口形成的微气压波具有较强的非线性。该微气压波幅值的数量级达到102 Pa,难以用传统的CFD方法（2阶精度）精确模拟。基于高阶谱差分的CAA模型是一种值得尝试的方法。CAA方法能在强非线性区域保持流体变量和声学变量的传递精度,高阶谱差分方法能够融入非结构网格,获得较高的计算效率和几何灵活性。本文在动模型试验平台开展200～350 km/h速度下的微气压波缩比试验研究；采用基于3阶谱差分的CAA方法,对轴对称圆管模型,数值研究了管口气压爆波的产生和近场辐射特性。数值结果和缩比试验结果的一致性,验证了该数值方法的准确性和可靠性。

英文摘要：

Nonlinear acoustical effects of micro-pressure waves at the tunnel portal are shown obviously when 300 km/h high-speed trains run through the tunnel.The micro-pressure wave is about of the order of the magnitude of 102 Pa which can not be simulated accurately by using the traditional CFD method （2 order precision）.The CAA model based on the high-order spectral difference method is an alterative way.The CAA method can keep the accuracy of fluid and acoustic variables simultaneously for the region apparant with strong nonlinear acoustical effects.In this paper,the high-order spectral difference method was used to involve the unstructured grid to achieve high computational efficiency and good geometric flexibility.Micro-pressure wave experiments were performed by using the scaled tunnel model and scaled train model for the speed of 200～350 km/h.Computational analysis was made to model the micro-pressure waves by using the 2 dimensional axis-symmetric CAA model with the 3-order spectral difference method.The results of the experiments were in good agreement with the results of numerical calculations.