• 主题
高级搜索  >
历史搜索 清空历史
首页> 外文学位 >Direct and large-eddy simulation of compressible flows with spectral/hp element methods.
【24h】

Direct and large-eddy simulation of compressible flows with spectral/hp element methods.

机译：使用谱/ hp元素方法直接和大涡模拟可压缩流。

获取原文
获取原文并翻译 | 示例
页面导航
  • 摘要
  • 著录项
  • 相似文献
  • 相关主题

摘要

Hi-fidelity simulation of compressible turbulent flows serve as powerful research tools for understanding the complex flow physics that help engineers to improve the design and performance of various fluid flow systems. Rapid growth of supercomputers has made simulation studies very attractive to the turbulence research community. Two popular approaches are direct numerical simulation (DNS) and large-eddy simulation (LES). While DNS is the more accurate approach, computational cost often limits its applicability to only simple flow geometries. LES on the other hand is computationally more efficient than DNS and as such has received considerable attention lately. There have been limited attempts to perform LES of engineering flows using high-order numerical schemes.;In this dissertation two spectral element based high-order LES methodologies for simulating flows in complex geometries are developed. The first method combines a two-dimensional unstructured nodal discontinuous Galerkin spectral element scheme with a triangle based filtering approach. The success of the method is demonstrated through simulation of two-dimensional plane channel flow at high Reynolds number. The second methodology is developed for three-dimensional flows using a Chebyshev multidomain, spectral collocation scheme. A novel interpolant-projection filtering on hexahedral elements facilitates simulation of flows at high Reynolds numbers. Low numerical errors, flexible meshing and high parallelization efficiency makes this method advantageous over other high-order schemes that are in practice. The numerical tool is used for detailed investigation of three-dimensional flow in dump-combustors. Dump-combustors are used as combustion devices in ramjet and turbojet engines. Fundamental understanding of the flow is essential for successful implementation of various control strategies that could improve engine performance. Compressibility effects on the flow, under different inflow conditions and Reynolds numbers, are analyzed. One of the principal findings is the different response of the transitional and turbulent shear layers with increase in compressibility. Increase in compressibility for the transitional flow leads to an increase in the growth rate of the shear layer due to larger production of turbulent kinetic energy. While for the turbulent shear layer, the growth rate was inhibited with increase in compressibility as a result of higher pressure-dilatation.
机译：可压缩湍流的高保真模拟是了解复杂流物理学的有力研究工具，可帮助工程师改善各种流体流系统的设计和性能。超级计算机的快速发展使仿真研究对湍流研究界非常有吸引力。两种流行的方法是直接数值模拟（DNS）和大涡流模拟（LES）。尽管DNS是更准确的方法，但计算成本通常将其适用性限制为仅适用于简单的流几何。另一方面，LES在计算上比DNS更高效，因此最近受到了相当多的关注。使用高阶数值方案进行工程流的LES的尝试有限。本论文开发了两种基于频谱元素的高阶LES方法来模拟复杂几何形状中的流。第一种方法将二维非结构化节点不连续Galerkin光谱元素方案与基于三角形的滤波方法结合在一起。通过在高雷诺数下模拟二维平面通道流动证明了该方法的成功。第二种方法是使用Chebyshev多域频谱搭配方案为三维流开发的。在六面体单元上进行新颖的内插投影滤波有助于模拟高雷诺数下的流动。低数值误差，灵活的网格划分和较高的并行化效率使该方法优于实际中的其他高阶方案。该数值工具用于详细研究倾卸式燃烧器中的三维流动。翻斗燃烧器用作冲压喷气发动机和涡轮喷气发动机中的燃烧装置。对流量的基本了解对于成功实施可以改善发动机性能的各种控制策略至关重要。分析了在不同流入条件和雷诺数下，压缩性对流动的影响。主要发现之一是随着可压缩性的增加，过渡剪切层和湍流剪切层的响应不同。由于较大的湍动能产生，过渡流的可压缩性增加导致剪切层的生长速率增加。而对于湍流的剪切层，由于较高的压力膨胀而随着可压缩性的增加而抑制了生长速率。

著录项

  • 作者

    Sengupta, Kaustav.;

  • 作者单位

    University of Illinois at Chicago.;

  • 授予单位 University of Illinois at Chicago.;
  • 学科 Engineering Mechanical.
  • 学位 Ph.D.
  • 年度 2009
  • 页码 174 p.
  • 总页数 174
  • 原文格式 PDF
  • 正文语种 eng
  • 中图分类 遥感技术;
  • 关键词

相似文献

  • 外文文献
  • 中文文献
  • 专利
获取原文

客服邮箱：kefu@zhangqiaokeyan.com

京公网安备：11010802029741号 ICP备案号：京ICP备15016152号-6 六维联合信息科技 (北京) 有限公司©版权所有

  • 客服微信

  • 服务号