权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Improvement of Ultra-High Lift Low-Pressure Turbine Blade Aerodynamic Performance Based on Evolutional Optimization Technique

基于进化优化技术的超高升力低压涡轮叶片气动性能改进

基本信息

批准号：
17560134
负责人：
FUNAZAKI Kenichi
金额：
$ 2.27万
依托单位：
Iwate University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2007
项目状态：
已结题

项目摘要

This study dealt with experimental and numerical studies on the flow field around a low-pressure linear turbine cascade whose solidity was changeable. The purpose of them was to clarify the effect of incoming wakes upon the aerodynamic loss of the cascade that wasaccompanied with separation on the airfoil suction surface, in particular for low Reynolds number conditions and/or low solidity conditions. Cylindrical bars on the timing belts worked as wake generator to emulate wakes that impacted the cascade. Pneumatic probe measurement was made to obtain total pressure loss distributions downstream of the cascade. Hot-wire probe measurement was also conducted over the airfoil suction surface. Besides, LES-based numerical simulation was executed to deepen the understanding of the interaction of the incoming wakes with the boundary layer containing separation bubble.This study also developed a new RANS-based method for predicting bypass transition of the boundary layer using intermittency t … More ransport equation. The base program was based on the boundary-layer analysis code given by Schmidt and Patankar (1988), implemented with Myong-Kasagi k -e turbulence model. The intermittency transport equation proposed in this study was the modification of Cho and Chung model (1992) with respect to the diffusion term and empirical model constants. The intermittent behavior of the transitional flow was invoked in the computation when the momentum-thickness based Reynolds number exceeded a criterion given by the empirical correlation of Abu-Ghannam and Shaw (1980). The method proposed in this study was applied to the prediction of boundary layer transition under the influence of free stream turbulence and pressure gradient. Through the comparison of the calculated results with the corresponding experimental data, for example ERCOFTAC T3A, the proposed method was proved to have a potential as a predictive tool of FST (free stream turbulence intensity)-induced boundary layer transition.This study lastly carried out LES investigation, along with measurements, on the interaction between inlet free stream turbulence and boundary layers with separation bubble over ultra-high lift low-pressure turbine airfoils. The cross section of the test airfoils is typical for highly-loaded LP turbines for civil aeroengines. The solidity of the cascade can be reduced by increasing the airfoil pitch by at least 25%, while maintaining the throat in the blade-to-blade passage. Reynolds number examined is 57,000, based on chord length and averaged exit velocity. Free-stream turbulence is about 0.85% (no grid condition) and 2.1% (with grid condition). Hot-wire probe measurements of the boundary layer are carried out to obtain time-averaged and time-resolved characteristics of the boundary layers under the influence of the freestream turbulence. A newly developed probe positioning tool, which is installed downstream of the cascade with minimal blockage, enables precise probe positioning along lines normal to the airfoil surface. Numerical analysis based on high-resolution LES (Large-Eddy Simulation) is executed to enhance the understanding of the flow field around the Ultra-High Lift and High Lift LP turbine airfoils. Emphasis is placed on the relationship of inherent instability of the shear layer of the separation bubble and the free-stream turbulence. Standard Smagorinsky model is employed for subgrid scale modeling. The flow solver used is an in-house code that was originally developed by one of the authors as FVM (Finite Volume Method)-based fully implicit and time-accurate Reynolds-Averaged Navier-Stokes code. Homogeneous isotropic turbulence created with SNGR (Stochastic Noise Generation and Radiation) method using von Karman-Pao turbulent energy spectrum is applied in the present study for the emulation of inlet turbulence. Less

本文对变稠度低压线性涡轮叶栅的流场进行了实验和数值研究。其目的是阐明来流尾迹对翼型吸力面分离叶栅气动损失的影响，特别是在低雷诺数和/或低稠度条件下。同步带上的圆柱形条起到了尾迹发生器的作用，模拟了影响级联的尾迹。通过气动探头测量，得到了叶栅下游的总压损失分布。在翼型吸力面上还进行了热线探头测量。此外，为了加深对来流尾迹与含有分离气泡的边界层的相互作用的理解，本文还发展了一种新的基于RANS的方法，利用间歇性t-…来预测边界层的绕流转变更多的运输方程式。BASIC程序基于Schmidt和Patankar(1988)给出的边界层分析程序，采用Myong-Kasagi k-e湍流模型实现。本文提出的间歇性输运方程是对Cho和Chung模型(1992)关于扩散项和经验模型常数的修正。当基于动量-厚度的雷诺数超过Abu-Ghannam和Shaw(1980)的经验关联式所给出的准则时，计算中引用了过渡流的间歇行为。将本文提出的方法应用于自由流湍流和压力梯度影响下的边界层转折预测。通过计算结果与ERCOFTAC T3A等相应实验数据的比较，证明该方法具有预测FST诱导边界层转变的潜力。最后，本文对超高升程低压涡轮翼型进口自由流湍流与带有分离气泡的边界层的相互作用进行了大涡模拟实验研究。试验翼型的横截面对于民用航空发动机的高负荷低压涡轮来说是典型的。通过将翼型节距增加至少25%，同时保持叶片到叶片通道的喉部，可以降低叶栅的稠度。根据弦长和平均出口速度计算，雷诺数为57,000。自由流湍流约为0.85%(无网格条件)和2.1%(有网格条件)。利用热线探头对边界层进行了测量，得到了自由流湍流影响下边界层的时间平均和时间分辨特性。新开发的探头定位工具安装在叶栅下游，堵塞最小，能够沿垂直于翼型表面的直线精确定位探头。为了加深对超高升程和高升程低压涡轮翼型绕流场的了解，进行了基于高分辨率大涡模拟的数值分析。重点讨论了分离气泡剪切层的固有不稳定性与自由流湍流的关系。次网格模型采用标准的Smagorinsky模型。所使用的流动求解器是由其中一位作者开发的内部代码，该代码最初是基于FVM(有限体积法)的全隐式和时间精确的雷诺平均Navier-Stokes代码。本文采用von Karman-Pao湍流能谱，采用随机噪声生成与辐射(SNGR)方法产生均匀各向同性湍流来模拟进气湍流。较少

项目成果

期刊论文数量（0）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

航空エンジン用低圧タービンの高負荷化に関する研究(wake通過時の剥離を伴う翼面境界層の動的挙動の時間平均的理解)

航空发动机低压涡轮高载荷研究（尾流通过过程中机翼边界层分离动态行为的时间平均理解）

DOI：
发表时间：
2008
期刊：
日本機械学会論文集B編 74
影响因子：
0
作者：
船崎;田中;小野;山田;菊地;谷口
通讯作者：
谷口

Studies on High-Lift LP Turbine Airfoils of Aero Engines (Understanding of Time-Averaged Behaviors of Separated Boundary Layer under the Influence of Incoming Wakes)

航空发动机高升力低压涡轮翼型的研究（了解传入尾流影响下分离边界层的时间平均行为）

DOI：
发表时间：
2008
期刊：
Transaction of JSME B, 74
影响因子：
0
作者：
FUNAZAKI Ken-ichi;YAMADA Kazutoyo;CHIBA Yasuhiro and TANAKA Nozomi;Funazaki Ken-ichi et. al.
通讯作者：
Funazaki Ken-ichi et. al.

Numerical and Experimental Studies on Separated Boundary Layers over Ultra-High Lift Low-Pressure Turbine Cascade Airfoils with Variable Solidity: Effects of Free-stream Turbulence