【作者】 姜健；

【导师】 刘波；

【作者基本信息】 西北工业大学 ， 流体机械及工程， 2006， 硕士

【摘要】 为进一步发展和完善多级轴流叶轮机械内三维紊流流场的数值模拟技术,本文围绕该领域内的若干关键问题展开了研究。 本文首先推导得出了不受坐标系限制的张量形式的流体运动学基本方程组。引入正交曲线坐标系以及拉梅系数,将张量形式的方程组展开到相对圆柱坐标下并投影到计算空间上。在此基础上,详细推导得出了矢通量按正负特征值分裂以后的亚通量的统一形式,不仅简化了计算程序,而且为使用现代先进数值格式打下了基础。 分析了现代先进数值格式的构造原则。将高分辨率的三阶ENN格式应用于三维叶栅紊流流场的数值模拟,并结合无矩阵求逆运算的LU-SGS隐式解法提高了计算速度,使得叶栅内复杂流动的数值模拟问题在精度和计算效率两个方面均有较好的效果。 参考动静干涉面处理的“混合平面法”,本文提出并讨论了动静干涉而处理应该保证的两个问题:流动参数的守恒型和流动参数的上下游相互传递。以此为出发点,构造了两大类动静干涉面处理模型,即:动静干涉面重合处理模型及动静干涉面重叠处理模型。通过算例计算检验,验证了本文所发展的这两大类干涉面处理模型的可行性。 对网格生成中需要注意的若干关键问题进行了讨论和分析,结合本文研究对象,提出了相应的网格生成方法。利用VC++开发了一套适用于叶轮机械内流场数值计算的界面化网格生成软件,可以生成平面叶栅、直列叶栅和三维通道叶栅的计算网格,具有较多的控制参数,能够快速高效且直观地生成网格。 在上述一系列研究工作的基础上,结合本文所设计的串行分区计算流程,本文较完整地建立了多级轴流叶轮机械内三维紊流流场数值模拟系统。通过对某两级风扇近设计点和某带进口导叶的三级轴流压气机设计转速下多个状态的计算以及对计算结果的详细分析,表明了本文算法具有较高的激波捕捉能力,且有一定的精度,同时也证明了本文所开发的网格生成软件的有效性。 文的工作为进一步发展和应用高精度高分辨率格式以及进一步开展动静干涉面处理的研究打下了良好的基础,对深入了解多级叶轮机械内部流动特性并指导设计具有较高的学术价值和工程实用价值。本文有针对性的研究工作,为多级更多还原

【Abstract】 To improve the numerical simulation technique for internal flow of multistage axial flow turbomachinery, several key problems in this area arc researched and developed in this paper.Equations in form of tensor for describing fluid dynamics are presented, which are free of coordinates. Equations in relative cylindrical coordinate system are educed by introducing orthotropic curvilinear coordinate system and Lame coefficient, and then projected to the computational space. The uniform expressions of flux vector after splitting are presented to simplify the computation procedure and make preparations to use the advanced finite difference schemes.Principles for constructing advanced finite difference schemes are analyzed. Then using high resolution three-order ENN scheme for simulating 3D turbulent flow in blade rows, applying LU-SGS implicit method to avoid calculating inverse matrix, the accuracy and efficiency of numerical simulating for complex flow in blade rows can be gained preferable effect.Two qualifications of treatment for rotor-stator interferential surface are discussed by consulting "mixing-plane method" , one is conservativeness of flow parameters in the interferential surface and the other one is cross-transmit of flow parameters between upstream section and downstream section. Based on these two qualifications, two classes of treatment model for rotor-stator interferential surface are presented, one is treatment based on the joined grid between rotor and stator, the other one is treatment based on the overlapped grid between rotor and stator. The validity of these two classes of treatment model is demonstrated by analyzing the numerical simulation results of two examples.Some typical problems which should pay more attention to in grid generation are discussed, a series of grid generation methods are presented by aiming at the features of research object in this paper. A set of grid generation software is developed by using Visual C++ computer language, it can generate H type grid in plane blade row and 3D blade row. The interface of this software has many control parameters, so it can generategrid fleetly and efficiently.Base’d on the above research, a numerical simulation system for internal flow of multistage axial flow tubromachinery is developed according to the serial partitioning algorithm presented in this paper. The validity of this system is demonstrated by numerical simulation of a two stages fan in near design condition and a three stages axial flow compressor with IGV at design rotating speed. The numerical results show that the numerical method developed in this paper has better resolution and definite accuracy and the dependability of the grid generation software is also testified.The work of this paper can be used in further research and development of high order accuracy and high resolution schemes as well as treatment for rotor-stator interferential surface, it also make some contributions for the numerical simulation of multistage axial flow turobmachinery and have better theoretic value as also broad technical application foreground.更多还原