【作者】 祝昭；

【导师】 周正贵；

【作者基本信息】 南京航空航天大学 ， 航空宇航推进理论与工程， 2008， 硕士

【摘要】 本文分两部分,第一部分是转/静交界面处理方法的研究。在对叶轮机械进行数值模拟时,转/静交界面的处理是十分关键的。研究不同的交界面处理方法对计算结果的影响,对于提高叶轮机械数值模拟的精度和效率具有重大意义。过去的二十年里,国内外的学者们提出了一系列交界面的处理方法,并在CFD商用软件中得到了广泛地应用。本文研究的主要目的是,系统地比较不同交界面处理方法对计算结果的影响,为叶轮机数值模拟交界面处理方法的选择提供参考依据。为了实现上述研究目的,本文的工作从以下几个步骤展开:1)作为整个研究的理论基础,对混合面法(Mixing Plane)、冻结转子法(Frozen Rotor)、滑移面法(Sliding Plane)几种应用较为广泛的交界面处理方法进行详细的介绍。2)发挥二维数值计算速度快的优势,对某型冲压涡轮叶中截面叶栅进行数值模拟,比较不同交界面处理方法对计算结果的影响。结果表明,采用混合面处理交界面时,叶栅的气流转角和总压恢复系数都要比滑移面的要大,而且随着周向间距和相对转速的减小,两者的差异越来越大。3)对冲压涡轮进行三维数值模拟,比较不同交界面处理方法对涡轮的总体性能计算结果的影响。结果表明,不同的交界面处理方法对流量和总压比没有明显的影响,但是对效率有一定的影响。转速越低,效率的差异越大;尤其是当涡轮的工作状态接近不稳定边界时,效率的差异更大。4)选取NASA STAGE35作为研究对象,分析不同交界面处理方法对压气机总体性能计算结果的影响。不同的交接面处理方法总压比的计算结果差别较小,但是效率的计算结有差异较大。随着转速和流量的减小,不同交界面处理方法所得计算结果的差异越来越大。将数值计算的结果同实验数据进行比较,发现采用滑移面法和冻结转子法处理交界面时,计算结果比混合面法更接近实验值。通过以上计算,说明在对涡轮一类叶轮机械进行数值模拟时,交界面的处理方法对计算结果的影响不大。采用混合面法处理转静交界面的定常计算,不仅计算精度和非定常计算差别很小,而且计算速度快。在对压气机一类作功的叶轮机械进行数值模拟时,交界面处理方法的选择对计算结果的影响较大。采用冻结转子法处理转/静交界面可以达到同非定常计算同样的精度,而且花费的时间要少。论文的第二部分是涡轮结构与气动分析。文中提出了一种根据叶型坐标数据,求解叶型的几何参数的算法。首先对测绘数据进行三次样条密集插值,然后求出叶型的中弧线,并通过最小二乘法对中弧线进行修正,最后得出叶型的各项几何参数。通过对冲压涡轮静子和转子叶片上几个型面几何参数的求解,验证了这种算法的可行性。更多还原

【Abstract】 This paper consists of two parts. The frist part is the investigation on rotor/stator interface processing method. The processing method of the rotor/stator interface is the key in numerical simulation of turbomachinery. To improve the precision and efficiency of turbomachinery simulation, it’s of great important to investigate the influence of different interface processing method to the simulation result. In the past twenty years, researchers gave series of approach to simulate the interface, which was extendly used in various CFD software. This dissertation is aimed towards comparing the computing result of different rotor/stator interface processing method, providing reference for the choice of interface processing method in turbomachinery numerical simulation.For the sake of realization research purpose above, this dissertation is organized as follow:1) As the theories foundation of whole dissertation, sever different approaches, such as mixing plane, frozen rotor, sliding plane are introduced in detail.2) Take advantage of fast speed of 2d numerical simulation, flow field of middle section of turbine blade is simulated, and apply different approaches to simulate the rotor/stator interface. Result show that when apply mixing plane method, flow turning angle and total pressure recovery coefficient are bigger than sliding plane method. The difference of result becomes larger when the gap and translation speed turn small.3) The detailed numerical simulation on a ram turbine is done, anaysis the influence of different rotor/stator interface processing method to numerical result of the tubine’s overall performance. The result show that interface treatment have no significant effect on flow mass and total pressure ratio, but have certain effect on stage efficiency. The faster the rotation speed, the larger the difference of effciency. Especially when working state is located near the instability boundary, the difference became even larger.4) Take the NASA STAGE35 as study object, anaysis the influence of different rotor/stator interface treatment to numerical result of the compressor’s overall performance. Study imply that when the interface is simulate by frozen rotor or sliding plane method, the numerical result agreed well with experimental test data for overall performance than mixing plane method. When take mixing plane method to simulate interface, the efficiency is biger than test data, and the tatal pressure ratio is smaller than test data. In addition, the difference of numerical result of different interface treatment becomes larger, when the flow mass and rotating speed become low.Through the above research, we find that the rotor/stator interface treatment have no significant effect on the numerical result of turbine. The steady computation,which uses mixing plane method to simulate the interface, not only can get the precision as unsteady computation, but also calculate fast. On the other hand, the rotor/stator interface treatment has a great influence on the numerical result of the compressor. Making use of frozen rotor model to simulate the interface, the precision is high than mixing plane, and the computation speed is faster than sliding plane.The second part of thi.s paper is the analysis of configuration and aerodynamic character. In the paper, a new algorithm is applied to calculate the geometric parameters of blade profile according to the surveying data of the blade profile. Fristly, reviews cubic spline curve of interpolation on the surveying data, then obtain the central arced curve of the blade section, correct the central arced curve with least square method, at last calculate various geometric parameters of the blade. By solving the geometric parameters of a ram tubine, feasibility of the algorithm is validated.更多还原