哈尔滨工业大学学报  2019, Vol. 51 Issue (1): 94-101  DOI: 10.11918/j.issn.0367-6234.201801008 0

### 引用本文

LIU Jian, QIAO Weiyang, DUAN Wenhua. Effect of lean/bowed vane on the unsteady performance of transonic turbine[J]. Journal of Harbin Institute of Technology, 2019, 51(1): 94-101. DOI: 10.11918/j.issn.0367-6234.201801008.

### 文章历史

Effect of lean/bowed vane on the unsteady performance of transonic turbine
LIU Jian, QIAO Weiyang, DUAN Wenhua
School of Power and Energy, Northwestern Polytechnical University, Xi'an 710072, China
Abstract: To investigate the effect of lean/bowed vane configurations on the aerodynamic performance and unsteadiness in transonic high-pressure turbine, the full three dimensional viscous unsteady numerical simulation were performed by solving N-S equations based on SAS SST method.The influence of bowed /lean vanes on turbine efficiency and efficiency fluctuation were investigated, and the action of vane modeling to the aerodynamic total perturbation level and the amplitude of each vane passing frequency were analyzed. The linking of the pressure fluctuation on blade surface with flow distortions was accomplished by comparing instantaneous pressure fluctuation contours of blade with space-time maps, which can reveal the mechanism of the influence of the vane modeling. The results indicate that the turbine efficiency is promoted with positive lean and bowed vane modeling, and the fluctuation of stage turbine is repressed, which is beneficial to the smooth running of the turbine stage. The aerodynamic disturbance on the rotor blade is dominated by the moving of vane trailing edge shock system, and the vane modeling can reduce the perturbation level on the rotor blade. For the positive lean vane, the unsteadiness at the root and tip region is reduced by the reduction of the amplitude of the first harmonic, but it is reduced by the reduction of the amplitude of second and higher harmonic at the middle region. For the positive bowed vane, unsteadiness is repressed by reducing the amplitude of third harmonic at the root region, and the first harmonic at the tip region and the amplitude of each harmonic is reduced at the middle region.
Keywords: transonic turbine     lean vane     bowed vane     aerodynamic performance     unsteadiness     numerical simulation

1 数值方法及计算对象 1.1 研究对象

 图 1 倾斜/弯曲导叶定义 Figure 1 Definition of lean/bowed vanes
1.2 数值模型与计算网格

 图 2 计算域及网格设置 Figure 2 Computation domain and mesh

 图 3 网格无关性验证结果 Figure 3 Validation of grid independence
 ${\rm{RM}}{{\rm{S}}_{{\rm{total}}}} = \sqrt {\frac{{\int_{{\rm{arc}}} {\left( {\sum\limits_{i = 1}^n {p_i^{'2}} } \right){\rm{d}}s} }}{{n\int_{{\rm{arc}}} {{\rm{d}}\mathit{s}} }}} .$

2 倾斜/弯曲导叶对涡轮气动性能的影响

 图 4 倾斜/弯曲叶片对涡轮性能参数沿展向分布的影响 Figure 4 Influence of lean/bowed vanes on spanwise distribution of turbine performance parameters of lean/bowed vanes
 $\mathit{\xi = }\frac{{{p_{{\rm{t0}}}} - {p_{{\rm{t1}}}}}}{{\overline {{p_{{\rm{t0}}}}} }},$

 ${\mathit{\eta }_{{\rm{stg}}}} = \frac{{1 - \left( {{T_{{\rm{t2}}}}/{T_{{\rm{t0}}}}} \right)}}{{1 - {{\left( {{p_{{\rm{t2}}}}/{p_{{\rm{t0}}}}} \right)}^{\left( {\frac{{k - 1}}{k}} \right)}}}}.$

3 倾斜/弯曲导叶对涡轮非定常性影响

3.1 倾斜/弯曲导叶对非定常扰动强度影响

 图 5 倾斜/弯曲叶片对跨声速涡气动激励的影响 Figure 5 Influence of stator and rotor blade of different vane models on transonic aerodynamic excitation

3.2 转子叶片气动激励分析

 图 6 不同导叶造型时转子叶中压力波动的时空图 Figure 6 Space-time figure of pressure perturbation at rotor mid-span for different vane models

 图 7 直导叶叶中位置瞬时压力波动云图 Figure 7 Instantaneous pressure perturbation contour for straight vane at mid-span

3.3 倾斜/弯曲影响转子叶片激励的机理分析

 图 8 不同导叶构型对转子叶片不同谐频扰动强度的影响 Figure 8 Influence of different vane models on rotor blade excitation of different harmonics
 ${\rm{RM}}{{\rm{S}}_n} = \sqrt {\frac{{\int_{{\rm{arc}}} {p_{n - {\rm{amp}}}^{'2}{\rm{d}}s} }}{{2\int_{{\rm{arc}}} {{\rm{d}}\mathit{s}} }}} .$

 图 9 不同导叶构型转子叶中各谐频扰动强度分布 Figure 9 Distribution of rotor blade excitation of different harmonics for different vane models

4 结论

1) 正倾斜和正弯曲导叶可以有效地提升涡轮级效率，并且减小了涡轮级效率波动水平，使得涡轮运行更加平稳.

2) 通过关联流动畸变与非定常气动激励，确定了跨声速涡轮内部气动扰动的来源，同时揭示了倾斜和弯曲对叶片总的扰动强度的影响来源.在超跨声速状态下，涡轮转子叶片上气动激励主要来源于导叶尾缘激波在下游转子叶片上移动及反射产生的压力扰动.正倾斜和正弯曲导叶可以有效地降低转子叶片上总的气动扰动强度，但是两者降低转子叶片气动激励的机理不同.

3) 正倾斜导叶主要通过影响一阶谐频的扰动强度来降低转子叶根总扰动强度和增加叶尖的总扰动强度，但是转子叶中扰动强度降低则通过降低二阶及更高阶谐频上的扰动实现.

4) 正弯曲导叶转子叶根位置的扰动强度降低主要通过三阶谐频的扰动强度降低实现，叶尖区域的扰动强度降低主要通过一阶谐频扰动降低来实现，而叶中区域的扰动强度则是通过各阶谐频上扰动强度共同降低实现的.