Turbine Blade Row Optimization Through Endwall Contouring by an Adjoint Method

2015 ◽  
Vol 31 (2) ◽  
pp. 505-518 ◽  
Author(s):  
Jiaqi Luo ◽  
Feng Liu ◽  
Ivan McBean
Keyword(s):  
Turbine Blade ◽  
Adjoint Method ◽  
Blade Row ◽  
Endwall Contouring

Optimization of Endwall Contours of a Turbine Blade Row Using an Adjoint Method

2011 ◽  
Author(s):  
Jiaqi Luo ◽  
Ivan McBean ◽  
Feng Liu
Keyword(s):  
Turbine Blade ◽  
Adjoint Method ◽  
Optimization Method ◽  
Adjoint Equations ◽  
Navier Stokes ◽  
Design Parameters ◽  
Flow Equations ◽  
Blade Row ◽  
Flow Loss ◽  
Design Case

This paper presents the application of a viscous adjoint method in the optimization of a low-aspect-ratio turbine blade through spanwise restaggering and endwall contouring. A generalized wall-function method is implemented in a Navier-Stokes flow solver coupled with Menter’s SST k-ω turbulence model to simulate secondary flow with reduced requirements on grid density. Entropy production through the blade row combined with a flow turning constraint is used as the objective function in the optimization. With the viscous adjoint method, the complete gradient information needed for optimization can be obtained by solving the governing flow equations and their corresponding adjoint equations only once, regardless of the number of design parameters. The endwall profiles are contoured alone in the first design case, while it is combined with spanwise restaggering in the second design case. The results demonstrate that it is feasible to reduce flow loss through the blade redesign while maintaining the same mass-averaged flow turning by using the viscous adjoint optimization method. The performance of the redesigned blade is calculated and compared at off-design conditions.

Coupled aeroelastic oscillations of a turbine blade row in 3D transonic flow

2001 ◽  
Vol 10 (4) ◽  
pp. 318-324 ◽  
Author(s):  
Vitaly Gnesin ◽  
Lyubov Kolodyazhnaya ◽  
Romuald Rzadkowski
Keyword(s):  
Turbine Blade ◽  
Transonic Flow ◽  
Blade Row

The Impact of Blade-to-Blade Flow Variability on Turbine Blade Cooling Performance

2005 ◽  
Vol 127 (4) ◽  
pp. 763-770 ◽  
Author(s):  
Vince Sidwell ◽  
David Darmofal
Keyword(s):  
Turbine Blade ◽  
High Flow ◽  
Low Flow ◽  
Simplified Model ◽  
Selective Assembly ◽  
Turbine Blade Cooling ◽  
Cooling Flow ◽  
Blade Cooling ◽  
Blade Row ◽  
The Impact

The focus of this paper is the impact of manufacturing variability on turbine blade cooling flow and, subsequently, its impact on oxidation life. A simplified flow network model of the cooling air supply system and a row of blades is proposed. Using this simplified model, the controlling parameters which affect the distribution of cooling flow in a blade row are identified. Small changes in the blade flow tolerances (prior to assembly of the blades into a row) are shown to have a significant impact on the minimum flow observed in a row of blades resulting in substantial increases in the life of a blade row. A selective assembly method is described in which blades are classified into a low-flow and a high-flow group based on passage flow capability (effective areas) in life-limiting regions and assembled into rows from within the groups. Since assembling rows from only high-flow blades is equivalent to raising the low-flow tolerance limit, high-flow blade rows will have the same improvements in minimum flow and life that would result from more stringent tolerances. Furthermore, low-flow blade rows are shown to have minimum blade flows which are the same or somewhat better than a low-flow blade that is isolated in a row of otherwise higher-flowing blades. As a result, low-flow blade rows are shown to have lives that are no worse than random assembly from the full population. Using a higher fidelity model for the auxiliary air system of an existing jet engine, the impact of selective assembly on minimum blade flow and life of a row is estimated and shown to be in qualitative and quantitative agreement with the simplified model analysis.

scholarly journals Solution of Turbine Blade Cascade Flow Using an Improved Panel Method

2015 ◽  
Vol 2015 ◽  
pp. 1-6 ◽  
Author(s):  
Zong-qi Lei ◽  
Guo-zhu Liang
Keyword(s):  
Turbine Blade ◽  
Inviscid Flow ◽  
Panel Method ◽  
Experiment Data ◽  
Blade Cascade ◽  
Comparison With Experiment ◽  
Cascade Flow ◽  
Mesh Free ◽  
Blade Row ◽  
Flow Through

An improved panel method has been developed to calculate compressible inviscid flow through a turbine blade row. The method is a combination of the panel method for infinite cascade, a deviation angle model, and a compressibility correction. The resulting solution provides a fast flexible mesh-free calculation for cascade flow. A VKI turbine blade cascade is used to evaluate the method, and the comparison with experiment data is presented.

Computational Predictions of Heat Transfer and Film-Cooling for a Turbine Blade With Nonaxisymmetric Endwall Contouring

2011 ◽  
Vol 133 (4) ◽  
Author(s):  
Stephen P. Lynch ◽  
Karen A. Thole ◽  
Atul Kohli ◽  
Christopher Lehane
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Film Cooling ◽  
Three Dimensional ◽  
Turbulence Models ◽  
Turbine Engine ◽  
Cooling Flow ◽  
Endwall Contouring ◽  
Dynamics Simulations ◽  
Endwall Film Cooling

Three-dimensional contouring of the compressor and turbine endwalls in a gas turbine engine has been shown to be an effective method of reducing aerodynamic losses by mitigating the strength of the complex vortical structures generated at the endwall. Reductions in endwall heat transfer in the turbine have been also previously measured and reported in literature. In this study, computational fluid dynamics simulations of a turbine blade with and without nonaxisymmetric endwall contouring were compared to experimental measurements of the exit flowfield, endwall heat transfer, and endwall film-cooling. Secondary kinetic energy at the cascade exit was closely predicted with a simulation using the SST k-ω turbulence model. Endwall heat transfer was overpredicted in the passage for both the SST k-ω and realizable k-ε turbulence models, but heat transfer augmentation for a nonaxisymmetric contour relative to a flat endwall showed fair agreement to the experiment. Measured and predicted film-cooling results indicated that the nonaxisymmetric contouring limits the spread of film-cooling flow over the endwall depending on the interaction of the film with the contour geometry.

Three-Dimensional Aerodynamic Design Optimization of a Turbine Blade by Using an Adjoint Method

2009 ◽  
Author(s):  
Jiaqi Luo ◽  
Juntao Xiong ◽  
Feng Liu ◽  
Ivan McBean
Keyword(s):  
Design Optimization ◽  
Turbine Blade ◽  
Adjoint Method ◽  
Euler Method ◽  
Adjoint Equations ◽  
Design Parameters ◽  
Aerodynamic Design ◽  
Blade Profile ◽  
Profile Shape ◽  
Aerodynamic Design Optimization

This paper presents the application of an adjoint method to the aerodynamic design optimization of a turbine blade. With the adjoint method, the complete gradient information needed for optimization can be obtained by solving the governing flow equations and their corresponding adjoint equations only once, regardless of the number of design parameters. The formulations including imposition of appropriate boundary conditions for the adjoint equations of the Euler equations for turbomachinery problems are presented. Two design cases are demonstrated for a turbine cascade that involves a high tip flare, characteristic of steam turbine blading in low pressure turbines. The results demonstrate that the design optimization method is effective and the redesigned blade yielded weaker shock and compression waves in the supersonic region of the flow while satisfying the specified constraint. The relative effects of changing blade profile stagger, modifying the blade profile shape, and changing both stagger and profile shape at the same time are examined and compared. Navier-Stokes calculations are performed to confirm the performance at both the design and off-design conditions of the designed blade profile by the Euler method.

A Transport Model for the Deterministic Stresses Associated With Turbomachinery Blade Row Interactions

2000 ◽  
Vol 122 (4) ◽  
pp. 593-603 ◽  
Author(s):  
Allan G. van de Wall ◽  
Jaikrishnan R. Kadambi ◽  
John J. Adamczyk
Keyword(s):  
Turbine Blade ◽  
Transport Model ◽  
Three Dimensional ◽  
Tip Clearance ◽  
Two Dimensional ◽  
Mean Flow ◽  
Viscous Effects ◽  
Vortical Structures ◽  
Blade Row ◽  
The Mean

The unsteady process resulting from the interaction of upstream vortical structures with a downstream blade row in turbomachines can have a significant impact on the machine efficiency. The upstream vortical structures or disturbances are transported by the mean flow of the downstream blade row, redistributing the time-average unsteady kinetic energy (K) associated with the incoming disturbance. A transport model was developed to take this process into account in the computation of time-averaged multistage turbomachinery flows. The model was applied to compressor and turbine geometry. For compressors, the K associated with upstream two-dimensional wakes and three-dimensional tip clearance flows is reduced as a result of their interaction with a downstream blade row. This reduction results from inviscid effects as well as viscous effects and reduces the loss associated with the upstream disturbance. Any disturbance passing through a compressor blade row results in a smaller loss than if the disturbance was mixed-out prior to entering the blade row. For turbines, the K associated with upstream two-dimensional wakes and three-dimensional tip clearance flows are significantly amplified by inviscid effects as a result of the interaction with a downstream turbine blade row. Viscous effects act to reduce the amplification of the K by inviscid effects but result in a substantial loss. Two-dimensional wakes and three-dimensional tip clearance flows passing through a turbine blade row result in a larger loss than if these disturbances were mixed-out prior to entering the blade row. [S0889-504X(00)01804-3]

Aerodynamic Shape Optimization of a Turbine Blade Considering Geometric Uncertainty Using an Adjoint Method

2019 ◽  
Author(s):  
Jiaqi Luo ◽  
Yao Zheng
Keyword(s):  
Shape Optimization ◽  
Design Optimization ◽  
Mass Flow Rate ◽  
Turbine Blade ◽  
Flow Rate ◽  
Adjoint Method ◽  
Design Parameters ◽  
Performance Impact ◽  
Aerodynamic Shape ◽  
Geometric Uncertainty

Abstract Aerodynamic shape optimization of turbomachinery blades taking the performance impact of geometric uncertainty into account is presented in the paper. A continuous adjoint method for the steady-state Euler equations is used to calculate the first order (FO) sensitivities of performance functions to the design parameters. For each performance function, all the sensitivities can be obtained by about two equivalent flow computations, regardless of the number of design parameters. The performance changes due to the geometric variations are evaluated on use of the second order (SO) sensitivities. A direct-ad joint method is used to calculate the FO and SO sensitivities of performance functions to the basis modes of geometric variations, which are extracted from a covariance function using principal component analysis method. Firstly, the sensitivities of the mass-averaged adiabatic efficiency and mass flow rate to the basis modes of geometric variations for a three-dimensional turbine blade are calculated. The validations of sensitivity-based performance impact are then illustrated. For the optimization maximizing the adiabatic efficiency with mass flow rate constrained, a series of shape functions are imposed on the turbine blade to perturb the aerodynamic shape. For each deformed blade with respect to each design parameter, the statistic mean values of performance changes are evaluated by using the method of moment and then contribute to the calculation of the corresponding FO sensitivity of performance functions. The design optimization without and with geometric uncertainty are finally presented. The results are compared in detail to demonstrate the effects of geometric variations to the optimization, especially to the statistical performance of the optimized blades. Through design optimization, the shock loss can be significantly reduced, compared with the original blade. The optimized blade is more robust in respect of geometric uncertainty.

Study of Blade Sweep Effects of Compressor

2005 ◽  
Author(s):  
C. Xu ◽  
R. S. Amano
Keyword(s):  
Flow Field ◽  
Turbine Blade ◽  
Experimental Studies ◽  
Three Dimensional ◽  
Experimental Results ◽  
Numerical Analyses ◽  
Blade Design ◽  
3D Flow ◽  
Efficient Manner ◽  
Blade Row

The three dimensional blading had been used for years in the process of turbomachine designs. In need of turbine blade designs in an efficient manner, the current advancement of CFD technologies allows effective 3D predictions of a complex 3D flow field in turbine blade passages, which can improve the turbine blade performances. Since numerous advantages of 3-D CFD usage had been reported in the open literature, many industries already started to use 3D blading in their turbomachines. In addition, a blade lean and a sweep for the blade design had been also implemented to increase the blade row efficiency. Experimental studies have shown some advantages of these lean and sweep features. Most of the experimental results combine many other features together. However, it is difficult to determine what the effects of different features should be. In this study, detailed numerical analyses were developed and these were used to present the results to gain better understanding of different feature of 3D blading for turbine designers and engineers. Throughout this paper performance impacts on different 3D features are presented and the superiority of the present approach is discussed.

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