燃气轮机燃烧室中贴体网格的生成与应用

FORMATION AND APPLICATION OF BODY-FITTED CURVILINEAR GRID SYSTEM FOR MODELING GAS-TURBINE COMBUSTOR FLOWS

关键词:  燃气轮机  燃烧室  流动分布  数值计算  网格法

Key words:  Gas turbine  Combustor  Flow distribution  Numerical calculation  Grids method

摘要:

运用贴体坐标系统分别对燃气轮机燃烧室的冷态和热态流场进行了数值模拟。燃烧室的曲线壁面边界用Ｔｈｏｍｐｓｏｎ的非正交贴体坐标网格处理，并把ＳＩＭＰＬＥ算法应用到曲线坐标系下求解各守恒方程。采用双方程ｋ－ε模型来描述紊流特性；采用按简单的单步化学反应假设的Ａｒｒｈｅｎｉｕｓ－ＥＢＵ模型表述紊流燃烧；采用热通量法辐射模型来估算辐射通量和壁面温度。另外，还研究了冷态时不同旋流数和紊流强度对气流结构的影响。计算结果与实验数据基本一致，表明本文提供的计算方法可作为新型燃烧室设计的一种辅助手段。

Abstract:

In this paper, a body-fitted coordinate grid system technique for predicting inert and reacting turbulent swirling flows in a gas turbine combustor is described. The technique has the feature that each segment of the boundary is exactly fitted by some coordinate line or surface, without any interpolation at the boundaries. Thus in the application of a boundary-fitted grid system more accurate results will be achieved. The elliptic partial differential equations based on numerical coordinate transformation are, developed. By comparisons it is demonstrated that calculations are in agreement with experimental findings. It is concluded that the computer program using a nonorthogonal grid system for modeling the complex geometric combustor flows will be satisfactory.