【作者】 羌晓青；

【导师】 王松涛；

【作者基本信息】 哈尔滨工业大学 ， 动力机械及工程， 2009， 博士

【摘要】 近些年来,航空发动机和燃气轮机的迅速发展无一例外的都对压气机部件提出了更高压比、更高效率和稳定工作范围的要求。目前,由于材料和结构的约束,出于安全性考虑,压气机转子叶尖切线速度提升的幅度有限,要进一步提高气动负荷将会造成叶栅内严重的流动分离,降低叶栅效率甚至会引起叶片的失速颤振或压气机的喘振,导致严重的事故。基于这样的认识,本论提出了亚声速、高负荷低反动度附面层抽吸式压气机概念及相应的设计方法,通过理论分析和对设计实例的数值模拟、实验研究初步验证了该方法的可行性。本文首先通过理论分析阐述了低反动度附面层抽吸式压气机概念及相应的设计方法,同时对该类压气机在不同循环层面上的效率和损失评价方法进行了探讨和研究。采用低速重复级压气机实验数据,验证了本文所采用的数值方法模拟亚声速压气机流场的精度和可靠性。首先,将低反动度设计思想应用于低亚声速重复级压气机的改型,设计了一台高负荷的单级附面层抽吸式压气机,分别研究了低反动度动叶流场特点,及附面层抽吸对大折转角静叶流场和气动性能的影响;采用优化设计方法,对静叶前缘加速段及尾缘扩压段进行了细致的修型和调整,使具有附面层抽吸的静叶内流场结构得到进一步的优化,整级性能进一步提高;在设计背压下研究了单级低反动度压气机的变抽吸方案及非定常性能,结果表明,新设计的单级低反动度压气机具有良好的变工况性能;研究了在具有附面层抽吸的大折转角静叶中如何应用弯叶片技术,研究结果指出,由于高负荷静叶端区流动存在着强烈的二次流动,叶片正弯比反弯效果要好,叶片正弯使得端区负荷降低,有利于减少下端壁附面层抽吸槽的额外耗功;叶片反弯增加了端区叶片的负荷,加重了附面层的分离。在单级低反动度压气机成功设计的基础上,本文将单级概念推广到多级低反动度压气机概念,对某重型燃气轮机压气机的末三级进行了重新设计,在减少一级(减少4列叶栅)条件下,采用两级低反动度的附面层抽吸式压气机达到了比原三级压气机更高的性能指标。文中分析了这两级高亚声速进口的低反动度压气机的几何特点、总体性能及动静叶的详细流场,总结了改型设计存在的问题,并有针对性地提出了改进的设想和方向。为了验证低反动度概念的可行性和数值计算结果的可靠性,对单级低反动度附面层抽吸式压气机进行了实验研究。分别对静叶出口总压、节距平均参数沿叶高分布、等转速特性进行分析,通过对典型工况点下静叶出口流场分布特点和气动性能分析,探讨了附面层抽吸对大折转角扩压静叶内分离流动的控制机理。通过对实验测量数据与数值结果的对比,验证了低反动度附面层抽吸式压气机概念及其设计方法的可行性。更多还原

【Abstract】 In recent years, the rapid development of aero-engine and gas turbine request higher pressure ratio, higher efficiency and stability for the design of compressor parts. Currently, the tip speed of compressor rotor could not been significantly improved due to the constraints of material, structure and security. Further improvement of aerodynamic loading will lead to large scale separation, low efficiency, stall, fltter or even surge for the compressor. Based on this understanding, a subsonic highly loaded low-reaction boundary layer suction compressor concept and its design method are proposed in this dissertation. It is validated through theoretical analisis, numerical simulation and experiment study.In this dissertation, the low-reaction boundary layer suction compressor concept and its design method are firstly described through theorectical analysis. The evaluation method of efficiency and loss for this new tyoe of compressor is discussed at different cycle levels. The accuracy and realability of the numerical software used to simulate the flow field of subsonic compressor is verified by the experiment data of a certain low speed two stage repeated compressor.A low speed subsonic two stage repeated compressor is redesigned into a single stage highly loaded compressor by using the low-reaction design concept. The flow field and design feature of the low-reaction rotor blade and stator cascade with boundary layer suction are all studied and analyzed. By using optimization method, the acceleration section near leading edge and the diffusion section near trailing edge of the stator cascade are modified and shaved which leads to a better flow field structure and higher performance. The stage performance with different boundary suction flow rate as well as the unsteady performance is studied under the condition of design back pressure. The numerical results predict that the single stage has a good off-design performance. The bowed blade technique is also studied by applied into the high turning angle stator cascades with boundary layer suction. The results show that positive bowed blades have a better effect than negative ones because of the strong secondary flow at the endwall region of the highly loaded stator cascades. The positive bowed blades reduce the endwall loading and thus the extra consumption work of the endwall boundary layer suction is decreased. The negative bowed blades raise the endwall loading and emphasis the boundary layer separation. On the basis of successful design procedure of single stage low-reaction compressor, the single stage low-reaction design concept is developed into a multi-stage low-reaction concept. By using the multi-stage design method, the last three stages of a certain heavy duty gas turbine is redesigned with two stages low-reaction boundary layer suction compressor. The stage counts are reduced by one while it contains one rotor blade and three stator rows. The two stages low-reaction boundary layer suction compressor has higher performance than the original three stages compressor. The geometry features, total performance and detailed flow field of the two stages is then analyzed. The open questions of the redesign work are summarized and the tentative ideas to improve them are given out.The experiment investigation of the single stage low-reaction boundary layer suction compressor is carried out to verify the feasibility of the low-reaction design concept and the accuracy of the numerical simulation. The total pressure contours and pitchwised averaged parameters along span at the stator exit as well as the speed line are analyzed. The flow control mechanism of boundary layer suction method is studied by the flow field and performance analysis of typical operation points. At last, the low-reaction boundary layer suction compressor concept and its design method is proved by the comparison of the experiment data and numerical results.更多还原