火箭推进

以某型火箭发动机用亚声速小展弦比燃气涡轮为研究对象,为进一步改善涡轮内部流场,提高了涡轮效率,通过调整导叶子午端壁型线曲率、采用导叶端弯的设计方法对涡轮进行了优化设计,其作用在于减小叶片通道二次流损失,并将导叶出口压力分布进行调整,从而减小叶顶泄漏损失。基于六面体网格,采用CFX流场分析软件对优化前后结构进行了数值计算,结果表明:优化后单通道无叶顶间隙模型涡轮效率提高1.4%; 采用正弯设计后,轮毂和叶顶处绝对和相对气流角显著增大,叶片中部气流角有所减小,整体分布更加均匀,消除了原型结构动叶轮毂区的流动分离; 优化后全通道模型围带间隙前后压差明显降低,泄漏量从7%降低至4.75%,涡轮效率提高5.9%。

In order to further improve the internal flow field and improve the turbine efficiency, a sub-sonic low aspect gas turbine for a certain rocket engine was taken as research object, the optimization was developed in this paper through the adjustment of meridional endwall's curvature and the design of curved guide vanes.Its function is to reduce the secondary flow loss and optimize the guide outlet pressure distribution at guide vanes outlet, thereby reducing the leak loss at blade top.Base on the hexahedron grid, CFX flow field analysis software was used to calculate the turbine performance.The result shows that the optimized turbine efficiency of single channel gap-less structure increases by 1.4%; the absolute and relative airflow angles at hub and tip of the blade are significantly increased after the curved blade was used, the airflow angle in the middle of the blade is reduced, and the overall distribution is more uniform, the flow separation of the prototype structure is eliminated; the relative leakage of blade tip with maze structure gap decreases by 7% to 4.75%,turbine overall efficiency increases by 5.9%.

引言
1 研究对象
2 优化改进思路
3 数值计算方法
4 仿真结果分析
5 结论

表1 涡轮设计参数<br/>Tab.1 Design parameters of turbine

表1 涡轮设计参数
Tab.1 Design parameters of turbine

图1 子午面型线优化<br/>Fig.1 Optimization of meridional endwall

图1 子午面型线优化
Fig.1 Optimization of meridional endwall

图2 积叠线及三维造型对比<br/>Fig.2 Stacking line and 3D model comparation

图2 积叠线及三维造型对比
Fig.2 Stacking line and 3D model comparation

图3 叶片通道及迷宫结构<br/>Fig.3 Blade passage and maze structure

图3 叶片通道及迷宫结构
Fig.3 Blade passage and maze structure

图4 叶片通道及叶顶间隙网格划分<br/>Fig.4 Mesh of blade and maze clearance

图4 叶片通道及叶顶间隙网格划分
Fig.4 Mesh of blade and maze clearance

表2 涡轮总体性能<br/>Tab.2 Overall performance of turbine

表2 涡轮总体性能
Tab.2 Overall performance of turbine

图5 导叶表面极限流线(吸力面)<br/>Fig.5 Extra streamline of vane(suction surface)

图5 导叶表面极限流线(吸力面)
Fig.5 Extra streamline of vane(suction surface)

图6 导叶表面静压分布对比<br/>Fig.6 Pressure contour of vane

图6 导叶表面静压分布对比
Fig.6 Pressure contour of vane

图7 导叶出口总压损失系数沿展向分布<br/>Fig.7 Total pressure loss coefficient distribution along span at outlet of vane

图7 导叶出口总压损失系数沿展向分布
Fig.7 Total pressure loss coefficient distribution along span at outlet of vane

图8 导叶出口压力系数沿展向分布<br/>Fig.8 Pressure coefficient distribution along span at outlet of vane

图8 导叶出口压力系数沿展向分布
Fig.8 Pressure coefficient distribution along span at outlet of vane

图9 叶顶间隙内压力(右:进口)<br/>Fig.9 Pressure contour of blade topclearance

图9 叶顶间隙内压力(右:进口)
Fig.9 Pressure contour of blade topclearance

图10 气流角沿展向分布<br/>Fig.10 Flow angle distribution along span

图10 气流角沿展向分布
Fig.10 Flow angle distribution along span

图11 动叶不同展向位置马赫数分布<br/>Fig.11 Mach contour at different span of blade

图11 动叶不同展向位置马赫数分布
Fig.11 Mach contour at different span of blade

图12 动叶表面极限流线(吸力面)<br/>Fig.12 Extra streamline of blade(suction surface)

图12 动叶表面极限流线(吸力面)
Fig.12 Extra streamline of blade(suction surface)

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备注

引言

1 研究对象

2 优化改进思路

3 数值计算方法

4 仿真结果分析

5 结论

期刊信息