Uncertainty Quantification for Direct Aeroacoustic Simulations of Cavity Flows
Uncertainty Quantification for Direct Aeroacoustic Simulations of Cavity Flows
复制标题
空腔流直接气动声学模拟的不确定性量化
DOI：
10.1142/s2591728518500445
复制
发表时间：
2019
影响因子：
1.9
通讯作者：
C. Munz
中科院分区：
文献类型：
--
作者：
Thomas Kuhn;Jakob Dürrwächter;F. Meyer;A. Beck;C. Rohde;C. Munz
研究了不确定输入参数对空腔流动气动声反馈的影响。所谓的罗西特反馈需要对噪声进行直接的数值计算，同时解决了流体力学和声学问题，以便捕捉声波和流体力学的相互作用。由于空间和时间尺度的大带宽，需要具有低耗散和色散误差的高阶数值格式来保留重要的小尺度信息。因此，本文采用基于高阶不连续Galerkin谱元方法的开源CFD求解器FLEXI，对具有层流上游边界层的开腔构型进行了直接模拟。为了分析确定性空腔模拟相对于随机输入参数的精度，我们建立了一个不确定性量化框架（UQ）。特别地，为了处理随机输入的均匀和正态概率分布，采用了一种具有Legendre和Hermite多项式基函数的非侵入式谱投影方法。结果表明，声学反馈机制对所研究的不确定输入参数具有强烈的非线性依赖性。对随机结果的分析为开腔流动的噪声产生过程提供了新的见解，并揭示了所实现的UQ框架的强度。
We investigate the influence of uncertain input parameters on the aeroacoustic feedback of cavity flows. The so-called Rossiter feedback requires a direct numerical computation of the acoustic noise, which solves hydrodynamics and acoustics simultaneously, in order to capture the interaction of acoustic waves and the hydrodynamics of the flow. Due to the large bandwidth of spatial and temporal scales, a high-order numerical scheme with low dissipation and dispersion error is necessary to preserve important small scale information. Therefore, the open-source CFD solver FLEXI, which is based on a high-order discontinuous Galerkin spectral element method, is used to perform the aforementioned direct simulations of an open cavity configuration with a laminar upstream boundary layer. To analyze the precision of the deterministic cavity simulation with respect to random input parameters, we establish a framework for uncertainty quantification (UQ). In particular, a nonintrusive spectral projection method with Legendre and Hermite polynomial basis functions is employed in order to treat uniform and normal probability distributions of the random input. The results indicate a strong, nonlinear dependency of the acoustic feedback mechanism on the investigated uncertain input parameters. An analysis of the stochastic results offers new insights into the noise generation process of open cavity flows and reveals the strength of the implemented UQ framework.