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1、哈尔滨工业大学硕士学位论文 I 摘 要 涡轴发动机主要用于军用 、 民用直升机，其发展与国防行业密切相关。 涡轮作为 涡轴发动机关键部件之一，发展一直制约着涡轴发动机乃至直升机的发展。涡轴发动机涡轮内部流场结构 极其 复杂，叶片展弦比较低 ，进口附面层相对 较厚，势必造成其流场内产生复杂的涡系结构、流道叶栅内的强横向二次流以及叶片端部 低能流体聚集，会造成叶栅性能的下降 。由于涡轴发动机的工况变化较大， 恶劣的流场结构会对涡轮变工况性能造成较大影响。涡轴发动机流量较其他航空发动机涡轮流量小很多， 其冷气流量也非常小，但 入口初温较高。另一方面，采用涡轴发动机的直升机工作于海洋、沙漠等恶劣环境，
2、气膜孔及排尘孔易于堵塞，因此， 涡轮的 冷却结构设计是 涡轴发动机 设计的一个难点也是重点。 本文以小流量涡轴发动机 涡轮为研究对象，针对于动力涡轮 第一级静叶 的工作特点，研究 在不同弯扭叶片 弯角、弯高与积迭线形式等 设计参数对气动性能的影响，提炼高负荷弯扭叶片的设计思想。 燃气涡轮入口初温较高，在最大起飞状态下，对第一级 导叶 及第一级动叶进行冷却结构设计。 设计中，充分考虑 了 发动机工作的恶劣环境与小冷气量的充分利用以及合理分配。对第一级 导叶 采用单元设计法、管网计算以及 1+3 维温度场计算程序对其进行设计，设计采用两腔设计保证流量的分配，大冲击孔、大气膜孔保证尘埃等不堵塞冷却结
3、构。尾缘劈缝扰流柱肋增大尾部换热，同时调整流阻以达到合理分配流量的目的。第一级动叶采用单元设计法、管网计算、 1+3 维温度场计算程序以及全三维气热耦合计算对其进行设计 ，设计采用多回转 单 通道充分利用冷气，叶顶大除尘孔除尘。最后对比管网计算、 1+3 维温度场计算以及全三维气热耦合计算结果， 分析造成计算差异的原因，并提出改进方法。 最终确定的动力涡轮 弯扭叶片 设计方法符合要求，并 提炼出针对该动力涡轮 导叶 的高负荷弯扭叶片的设计思想。对于冷却结构，设计出的两列叶栅冷却结构符合设计目标，温度场分布较为合理，冷气的流量分配符合工程实际，并对管网计算以及 1+3 维温度场提出了建设性的意见
4、。 关键 词 ：涡轴发动机；涡轮；弯扭叶片；冷却结构；管网 计算； 哈尔滨工业大学硕士学位论文 II Abstract Turboshaft engine is mainly applied to military and civilian helicopters, of which the development is closely related to defense industry. The development of turbine which is the essential component of turboshaft has always restricted the d
5、evelopment of turboshaft and even that of helicopters. The internal flow structure in turbine of turboshaft is extremely complicated, in which the blade aspect ratio is low and the boundary layer is thicker than other turbine, which would lead to complex vortex structure and strong crosswise second
6、flow in flow cascade as well as the accumulation of low energy fluid in endwall of blade, all the above deficiency could abate cascade performance and turbine efficiency. At the same time the working condition of turboshaft changes relatively fast, thus bad flow structure would have a great impact o
7、n changing working condition performance of turbine. Flux of turboshaft is much lower than that of others aeroengine, of which the flux of coolant is very low, but initial temperature of entrance in turboshaft is relatively high. On the other hand, helicopters with turboshaft are always used in seve
8、re environment such as ocean or desert that cooling hole and dust discharging hole are apt to be jammed, therefore the cool structure design of turbine design is difficult and important. In this paper, research object is turboshaft turbine of low flow rate, according to the work characteristic of di
9、fferent stage of dynamic turbine, the influence of design parameters on aerodynamic performance was investigated under different circumstances, such as bowed angle, bowed height and method of stacking line of bowed-twisted blade. Finally design method of high-load bowed-twisted blade is put forward.
10、 Under the maximum take-off state, according to high initial temperature in entrance of gas turbine, cool structure in rotor blade and stator blade of the first stage was processed. The design process has already given enough consideration to the match between severe environment and full use of low
11、cool flux when engine is working. Due to stator blade of the first stage cell design method, network computation and 1+3 dimensional temperature field computational program were used in the design process， in order to ensure distribution of flow two chamber design method was adopted, big impingement
12、 hole and big cooling hole were adopted to ensure that dust could not build up cool structure. Turbulence column rib of the trailing edge slot could enhance heat transfer in the tail; in the meantime flow resistance was adjusted to ensure reasonable 哈尔滨工业大学硕士学位论文 III distribution of flow. Due to rot
13、or blade of the first stage cell design method, network computation,1+3 dimensional temperature field computational program and full three-dimensional heat-flow coupling computation were used in the design process, in order to take full advantage of cool air multi-turn channel was adopted, in the bl
14、ade tip big dust hole was used for deducting. Eventually results of network computation, 1+3 dimensional temperature field computation and full three-dimensional heat-flow coupling computation were compared, the causes of computational distinction were analyzed and improved methods were promoted. Fi
15、nal bowed-twisted blade design method of dynamic turbine can cater to standard, and design method aiming at high load bowed-twisted blade of dynamic turbine was extracted. For cool structure, design of cool structure of two columns of cascade can satisfy design goal, distribution of temperature fiel
16、d is relatively reasonable, allocation of cool flux can meet with actual engineer, at last constructive suggestion is proposed for network computation and 1+3 dimensional temperature field. Keywords: turboshaft engine, turbines, curved and twisted leaves, cooling structure, pipe network calculations 哈尔滨工业大学硕士学位论文 IV 目 录 摘 要 . I Abstract .
