基于非嵌入式多项式混沌的不确定性CFD方法研究

项目名称： 基于非嵌入式多项式混沌的不确定性CFD方法研究

项目编号： No.51206052

项目类型： 青年科学基金项目

立项/批准年度： 2013

项目学科： 工程热物理与能源利用学科

项目作者： 王晓东

作者单位： 华北电力大学

项目金额： 25万元

中文摘要： CFD模拟是风力机、叶轮机械等气动设计的重要手段。当前普遍采用的确定性CFD模拟不能模拟现实流动问题中存在的不确定性变量的影响。而风力机、叶轮机械的气动性能对随机扰动因素可能很敏感。因此，基于确定性CFD模拟的气动设计必然存在潜在的风险。本项目提出采用重心高斯配点法构造多项式混沌来逼近随机变量的不确定性分析方法，并将多项式混沌以非嵌入方式引入到CFD模拟中。以风力机叶片为主要研究对象，模拟不同概率分布的随机变量对流动参数的影响，以及不确定性在流场内的传播。通过统计方法重构流动参数的随机响应特性，进而研究气动性能的不确定性变化，揭示边界条件、几何误差、工质属性、工作环境中的不确定性因素对风力机气动性能的影响规律。本项目的研究结果不仅可为发展高可信的CFD模拟方法提供思路，也可为基于CFD模拟的鲁棒气动设计奠定基础。

中文关键词： 多项式混沌；不确定性；CFD模拟；风力机；压气机

英文摘要： CFD simulation is an important method for aerodynamic design of wind turbine and turbomachinery. The current deterministic CFD simulations cannot take the impact of uncertain variables into account. However, these uncertainties always exist in real flow problems. There could be great potential risk of failure in aerodynamic designs which are based on such deterministic CFD simulations. For instance, the aerodynamic performance of wind turbine and compressor could be very sensitive to small perturbations. This project contributes to the development of a new non-deterministic CFD method by introducing stochastic polynomial chaos expansion into CFD simulations. A Barycentric Gaussian collocation method is proposed to build the polynomial chaos to approximate the random variables with respect to different probability distributions. The polynomial chaos expansion is coupled with CFD methodologies in a non-intrusive way to simulate the propagation of uncertainties in the flow field. The statistical property of flow variables and stochastic response of the aerodynamic performance can be rebuilt by statistical methods. Base on a good validation, the practical engineering applications focus on non-deterministic CFD simulations of wind turbine to reveal the inherent mechanism of the impact from uncertain boundary conditio

英文关键词： polynomial chaos；uncertainties；CFD simulation；wind turbine；compressor