粘弹性湍流减阻流动的POD低阶模型研究

项目名称： 粘弹性湍流减阻流动的POD低阶模型研究

项目编号： No.51206186

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： 王艺

作者单位： 中国石油大学（北京）

项目金额： 25万元

中文摘要： 粘弹性湍流减阻是流体输送系统中的一种重要的节能降耗技术，其经济和社会效益明显，在油气集输系统和长输管道等场合有广泛的应用前景。特征正交分解(POD)方法已被数值实践证明是流动传热问题的高精度快速预测方法，有利于推动减阻技术的大规模产业化应用。因此，本项目拟针对由Giesekus本构关系描述的粘弹性减阻流动问题，建立能准确快速描述减阻流动系统动力学特征的POD低阶投影模型，采用直接数值模拟获得建模所需样本数据，采用特征正交分解从样本中获取基函数，引入最优化理论在基函数集合中寻求最优的基函数组合以解决低阶模型最佳截断位置难以确定的问题，考虑多场耦合条件下的Galerkin投影，解决动量方程与本构方程的耦合投影难题，克服以往对这两组方程依次分离建模造成的粘弹性附加应力模拟结果精度过低的问题。研究成果将为粘弹性湍流减阻节能系统的设计运行提供理论依据和技术支持。

中文关键词： 粘弹性；减阻流动；特征正交分解；低阶模型；湍流

英文摘要： Viscoelastic turbulent drag reduction is an important technology for energy saving in fluid transporting systems, with apparent economic and social benefits. It has broad potential applications in oil and gas gathering and transporting systems and long-distant pipelines etc. Proper orthogonal decomposition (POD) method has been proved to be an efficient way for high-precision and fast prediction method by numerical practice so that it is helpful for large-scale industrial applications of drag reduction. Thus, this project will aim to the viscoelastic drag reduction problem described by Giesekus constitutive relation, and establish a POD projection model that can accurate and fast predict the dynamic characteristics of drag reducing flow. Direct numerical simulation will be applied to obtain samples for modelling; POD will be used to extract eigenfunctions from the samples; optimization theory will be introduced to search the optimal combination of eigenfunctions to solve the problem that the optimal truncated location of the reduced order model was hard to fixed. Galerkin projection for multi-field coupling will be considered to solve the problem coupling the momentum equation and the constitutive equation so that the existed problem that the model results for viscoelastic conformation had too low accuracy by pr

英文关键词： Viscoelasticity；Drag-reducing flow；Proper orthogonal decomposition；Reduced-order model；Turbulence