【作者】 黄璟晗；

【导师】 韩万金；

【作者基本信息】 哈尔滨工业大学 ， 动力机械及工程， 2010， 硕士

【摘要】 压气机作为燃气轮机的一个重要部件,对燃气轮机的效率和功率起着决定性的作用。现代大功率燃气轮机对压气机的性能提出了更高的要求,如高压比、高转速、高的效率,同时又要求其具有较高的可靠性、较长的使用寿命及较轻的重量。在总结了国内外关于多级轴流压气机气动性能数值模拟的相关文献基础上,本文对多级轴流压气机气动性能数值模拟的现状进行了综述,并介绍了CFD软件的主要特点以及它在我国现今的应用现状。为了掌握多级轴流压气机的气动性能以及总体布局和结构性能特点,本文使用Numeca软件对某燃气轮机多级轴流压气机的第14、15、16级进行了全三维数值模拟,三级压气机网格划分采用IGG完成,采用FINE进行计算,湍流模型选择的是单方程Spalart-Alimaras模型。通过对三级轴流压气机的三维流场的定常数值模拟研究,首先对该三级压气机的总体性能参数进行了分析;从各列叶片表面的型面压力分布、叶片表面极限流线、以及各叶片排出口处S3截面熵等值线分布等角度对该三级压气机的三个运行工况:设计工况、喘振工况及阻塞工况分析了压气机的叶型与叶片的设计特点。采用适用于多级轴流式叶轮机械流动的非定常数值求解方法Harmonic方法对该三级压气机进行了非定常数值研究。分析了14、15、16级的非定常流场,通过对一个周期内熵和压力的对比,分析了非定常条件下叶片排之间存在的非定常干扰,及其叶片表面气动负荷呈现的周期性变化。对各列叶片进行了叶片气动力负荷计算,并分析了在一周期内不同时刻的气动力、气动力矩和气动力方向角的波动及幅值变化。经过分析结果发现,随着出口背压的增大,流动越来越复杂。进口气流对静叶有较大的负冲角,在改进设计中应该改善动、静叶之间的匹配。近端壁附近的流动由于粘性摩擦力的作用和前面级流动的积累偏离了设计工况,可改善各级动静叶的气流角匹配和各级间的气流角匹配来提高整体性能。由尾迹和势流引起的压力波动必然会清晰地反映在叶片气动负荷的非定常波动上。更多还原

【Abstract】 As an important component of gas turbine, compressor plays a decisive role on the efficiency and power of gas turbine. Modern high-power gas turbine sets higher requirements on performance of compressor, such as high pressure ratio, high speed, high efficiency, but requires high reliability, long life and low weight.Based on the comprehensive research on simulation of aerodynamic performance of axial multistage compressor at home and abroad, the current developing status of numerical simulation of axial multistage compressor was reviewed. This paper gave a brief introduction about CFD chief characters and application in our country at present.In order to study the aerodynamic performance and configuration of axial multistage compressor, Numeca was used to carry out three-dimensional numerical simulation at No.14, 15, 16 stage of the multi-stage axial compressor. The meshes were generated by IGG, and used the single equation Spalart-Alimaras model to numerically simulate three stages of the compressor in FINE.Through three-dimensional numerical simulation of three stages of the axial compressor, total performance analysis for the stages of compressor was carried out firstly; analyzed blade design feature through studied profile static pressure, profile limit streamline, as well as the entropy contours on S3 section in three compressor operating conditions: design condition, surge condition, and choking condition.The three stages of compressor were studied by unsteady numerical solution of Harmonic method which applied for multi-stage axial turbo machinery. The unsteady flow field of the 14, 15, 16 stage was analyzed. The interference between the blades under unsteady condition and periodicity changes of the aerodynamic loads on blade surface were studied by contrast entropy and pressure in a cycle. This paper calculated aerodynamic load on each blade, analyzed the fluctuations and amplitude of the changes of aerodynamic force, aerodynamic torque and aerodynamic angle in different times in a cycle.The result showed that with the increase of the outlet pressure, the flow got more complex. Because of large negative incidence in inlet the of stator , rotor and stator matching should be improved in design. The flow of the end-wall deviated from the design condition because of the role of viscous friction and flow of the previous stage accumulation, so total performance could be improved by better match of flow angle between stages. Pressure fluctuations induced by the wake and the potential flow would clearly reflect in unsteady fluctuations of the aerodynamic load on the blade.更多还原