Part Reliability Design of Air-Cooled Turbine Blade Under Thermal Stress-Dependent Strength Using Polynomial Method

2010 ◽  
Author(s):  
Chun Nam Wong ◽  
Hong-Zhong Huang ◽  
Jingqi Xiong ◽  
Daijun Ling
Keyword(s):  
Thermal Stress ◽  
Turbine Blade ◽  
Strength Distribution ◽  
Interference Model ◽  
Polynomial Method ◽  
Structural Systems ◽  
Reliability Design ◽  
Application Range ◽  
Stress Dependent ◽  
Mean Function

In this paper, Lagrange factor polynomial method is developed to generate the stress-strength interference model with thermal stress-dependent strength. Accuracy of this method is investigated by an aeroengine air-cooled turbine blade. The computed reliability is quite high under several thermal stress modes. Then probability mean function estimated by this method has relatively low errors over most subintervals of the thermal stress dependent strength distribution. With this approach conditional thermal stress-dependent strength reliability of aeroengine structural systems can be established conveniently. Meanwhile the application range of the classical stress-strength interference model can be extended.

Weibull Distributed Stress-Dependent Strength Analysis of Aeroengine Alloy Using Lagrange Factor Polynomial

2010 ◽  
Author(s):  
Chun Nam Wong ◽  
Hong-Zhong Huang ◽  
Jingqi Xiong ◽  
Tianyou Hu
Keyword(s):  
Random Variable ◽  
Mass Function ◽  
Strength Distribution ◽  
Interference Model ◽  
Strength Analysis ◽  
Probability Mass Function ◽  
Application Range ◽  
Probability Mass ◽  
Stress Dependent ◽  
Mean Function

In this paper, the unilateral dependency of strength on stress is taken into account. And the stress-dependent strength is represented by a discrete random variable that has different conditional probability mass functions under different stress amplitudes. Then the Lagrange factor polynomial technique is developed to generate the stress-strength interference model with stress-dependent strength. This model assumes that the strength probability mass function is Weibull distributed, while the stress probability mass function is Normal distributed. Accuracy of this method is investigated by an aeroengine bearing cage alloy. Structural reliabilities are computed as 0.796 to 0.986 under several operation modes, which are analyzed by varying the Weibull shape parameter from 1 to 6. Then probability mean function estimated by Lagrange factor polynomial has relatively low errors over most span of the stress dependent strength distribution. With this approach stress-dependent strength reliability of aeroengine structural systems can be established conveniently. Meanwhile the application range of the classical stress-strength interference model can be extended.

scholarly journals Thermal–Fluid–Solid Coupling Analysis on the Temperature and Thermal Stress Field of a Nickel-Base Superalloy Turbine Blade

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3315
Author(s):  
Liuxi Cai ◽  
Yao He ◽  
Shunsen Wang ◽  
Yun Li ◽  
Fang Li
Keyword(s):  
Thermal Stress ◽  
Temperature Gradient ◽  
Turbine Blade ◽  
Turbine Blades ◽  
Nickel Base Superalloy ◽  
Barrier Coating ◽  
Thermal Stress Field ◽  
Nickel Base ◽  
Stress Damage ◽  
Superalloy Turbine Blade

Based on the establishment of the original and improved models of the turbine blade, a thermal–fluid–solid coupling method and a finite element method were employed to analyze the internal and external flow, temperature, and thermal stress of the turbine blade. The uneven temperature field, the thermal stress distribution characteristics of the composite cooling turbine blade under the service conditions, and the effect of the thickness of the thermal barrier coating (TBC) on the temperature and thermal stress distributions were obtained. The results show that the method proposed in this paper can better predict the ablation and thermal stress damage of turbine blades. The thermal stress of the blade is closely related to the temperature gradient and local geometric structure of the blade. The inlet area of the pressure side-platform of the blade, the large curvature region of the pressure tip of the blade, and the rounding between the blade body and the platform on the back of the blade are easily damaged by thermal stress. Cooling structure optimization and thicker TBC thickness can effectively reduce the high temperature and temperature gradient on the surface and inside of the turbine blade, thereby reducing the local high thermal stress.

Trivariant Lagrange Factor Polynomial for Discrete Rayleigh Distributed Reliability Analysis of Aeroengine Combustion Chamber Cylinder

2013 ◽  
Vol 10 (1) ◽  
Author(s):  
Chun Nam Wong ◽  
Yang Lu
Keyword(s):  
Combustion Chamber ◽  
Thermal Conditions ◽  
Economic Factors ◽  
Structural Variants ◽  
Temperature Dependent ◽  
Application Range ◽  
Linear Polynomial ◽  
As Stress ◽  
Stress Dependent ◽  
Dependent Probability

In most of the existing stress-strength interference (SSI) models, stress and strength are assumed to be independent structural variants. However, under severe thermal conditions, such as in aeroengine combustion chamber, this assumption may not hold. One structural variant, such as strength, may become unilateral dependent on another variant, such as stress or temperature. In addition, to evaluate the discrete reliability of structures using unilateral dependent structural variants, discrete SSI models were developed using not just linear polynomial or line segments, but higher order polynomials. These models are based on the trivariant Lagrange factor polynomial approach. Normal distributed temperature dependent stress and Rayleigh distributed thermal stress dependent strength are represented by discrete structural variants that possess unilateral dependent probability mean functions. Based on their dependence formulations, the trivariant Lagrange factor polynomial of the discrete SSI model was generated. Applicability of this method was validated by a specific aeroengine combustion chamber cylinder using different molding alloys. Meanwhile the application range of some existing SSI models is extended for interval shifted data. Comparing machinability, reliability, and economic factors, 1Cr11MoV was the most suitable alloy in the design.

Turbine Blade Aerodynamic Optimization Based on Variable Dimensionality Model

2011 ◽  
Vol 287-290 ◽  
pp. 2801-2804 ◽  
Author(s):  
Liang Bo Ao ◽  
Yuan Sheng Li ◽  
Lei Li ◽  
Zhi Xun Wen ◽  
Zhu Feng Yue
Keyword(s):  
Turbine Blade ◽  
Three Dimensional ◽  
Optimization Procedure ◽  
Polynomial Method ◽  
Aerodynamic Optimization ◽  
Quintic Polynomial ◽  
Global And Local Optimization ◽  
Optimization Efficiency ◽  
Global And Local ◽  
Present Section

The aerodynamic optimization for turbocharger turbine blade is studied using variable dimensionality analysis technology. The aerodynamic optimization procedure is decomposed to two steps: two-dimensional (2D) optimization and three-dimensional (3D) optimization based on the 2D optimal results. The quintic polynomial method with continuous three order derivatives is used to present section profile of three sections, root, middle and tip of blade. The 2D aerodynamic analysis and optimization are carried separately for different sections. Aerodynamic optimization for turbine blade is driven by the combination of global and local optimization arithmetic, with the 2D optimization blade as initial value, and profile parameter as design variable. The result shows that the calculation time is shortened and the optimization efficiency is improved, compared with the full 3D optimization under the same effect.

Heat Transfer and Thermal Stress Analysis of Gas Turbine Blade Considering Off-Design Condition

2021 ◽  
Author(s):  
Jeongwon Lee ◽  
Minho Bang ◽  
Hee Seung Park ◽  
Taehyun Kim ◽  
Hee Koo Moon ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Thermal Stress ◽  
Stress Analysis ◽  
Gas Turbine ◽  
Turbine Blade ◽  
Gas Turbine Blade ◽  
Thermal Stress Analysis
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