大膨胀比两级涡轮气动设计及数值研究

发布时间：2018-03-31 22:11

本文选题：高膨胀比　切入点：数值仿真　出处：《哈尔滨工业大学》2015年硕士论文

【摘要】：动力系统是各种航空、航天、航海设备的核心部件,动力系统的优劣直接决定了飞行器、航海器等设备的各项性能。动力系统一般分为电动力系统和热动力系统两大类。电动力系统具有航程小、速度低、噪声小的特点。热动力系统具有功率大、燃料的能量密度高、噪声大等特点。考虑到热动力系统功率大、航程远的优点,本文选用热动力系统,并设计了具有双压力级的高膨胀比涡轮。本文针对这种类型的涡轮进行了气动设计及数值仿真。设计的双压力级涡轮工作在最佳速比下,达到了较高的效率及输出功率。由于在大膨胀比涡轮中,静叶承担了很高的焓降,常规叶片很难满足相应的要求,因此,涡轮的两级静叶都选用了拉伐尔喷管来实现大焓降。为了保证涡轮动叶叶片不至于过小,采用了局部进气的方案。在设计过程中,首先,根据基本设计参数,按照选定方案,进行了涡轮的一维气动设计,确定了基本参数。之后,对涡轮各部件进行了三维建模及对涡轮三维流场数值仿真。三维数值计算结果表明,通过的流量及输出功率达到设计要求。同时,通过分析数值计算的结果,研究了喷管的性能参数及其内的流动状况,动叶流道内的流动分离、激波的特点,局部进气对涡轮内气动参数的影响及不同位置动叶叶片的载荷分布的影响。在对流场进行分析之后,利用有限元分析软件对涡轮动叶叶片的形变、应力进行了计算及分析,结果表明,应力集中一般出现在涡轮的叶片根部。最后,设计并分析了几种形式的涡轮出口的扩压段的减速效果及能量损失,通过采用逐步扩张型的扩压管,并采用波浪型的壁面,可以在较小的损失的条件下,增大出口气流分布均匀性,并达到较好的减速效果。
[Abstract]:Power system is the core component of all kinds of aeronautical, spaceflight and navigation equipments. The merits and demerits of power system directly determine the performance of aircraft, navigator and so on.Power system is generally divided into two categories: electric power system and thermal power system.The electric power system has the characteristics of small range, low speed and low noise.Thermal power system has the characteristics of high power, high energy density of fuel, high noise and so on.Considering the advantages of large power and long range of thermal power system, this paper selects the thermal power system and designs a high expansion ratio turbine with double pressure level.In this paper, the aerodynamic design and numerical simulation of this type of turbine are carried out.The designed double pressure stage turbine works at the optimum speed ratio and achieves high efficiency and output power.Due to the high enthalpy drop of the stator blade in the turbine with large expansion ratio, it is difficult for the conventional blade to meet the corresponding requirements. Therefore, both stages of the turbine still blade adopt the Laval nozzle to realize the large enthalpy drop.In order to ensure that the turbine blade blade is not too small, a local air intake scheme is adopted.In the design process, firstly, according to the basic design parameters and the selected scheme, the one-dimensional aerodynamic design of the turbine is carried out, and the basic parameters are determined.Then, three-dimensional modeling and numerical simulation of turbine three-dimensional flow field are carried out.The three-dimensional numerical results show that the flow rate and output power meet the design requirements.At the same time, by analyzing the results of numerical calculation, the performance parameters of nozzle and its internal flow condition, the flow separation in moving vane passage and the characteristics of shock wave are studied.After the flow field is analyzed, the deformation and stress of turbine blade blade are calculated and analyzed by using finite element analysis software. The results show that the stress concentration usually occurs at the blade root of turbine.Finally, the deceleration effect and energy loss of the expansion section of several forms of turbine outlet are designed and analyzed. By adopting a gradual expansion tube and a wavy wall surface, it is possible to reduce the loss under the condition of small loss.The distribution uniformity of outlet airflow is increased, and a good deceleration effect is achieved.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TK05

【引证文献】