Turbine Airfoil Heat Transfer Predictions Using CFD

2005 ◽  
Author(s):  
Anil K. Tolpadi ◽  
James A. Tallman ◽  
Lamyaa El-Gabry
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Turbulence Modeling ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Navier Stokes ◽  
Design System ◽  
Computational Fluid Dynamics Cfd ◽  
Turbine Airfoils ◽  
Typical Design

Conventional heat transfer design methods for turbine airfoils use 2-D boundary layer codes (BLC) combined with empiricism. While such methods may be applicable in the mid span of an airfoil, they would not be very accurate near the end-walls and airfoil tip where the flow is very three-dimensional (3-D) and complex. In order to obtain accurate heat transfer predictions along the entire span of a turbine airfoil, 3-D computational fluid dynamics (CFD) must be used. This paper describes the development of a CFD based design system to make heat transfer predictions. A 3-D, compressible, Reynolds-averaged Navier-Stokes CFD solver with k-ω turbulence modeling was used. A wall integration approach was used for boundary layer prediction. First, the numerical approach was validated against a series of fundamental airfoil cases with available data. The comparisons were very favorable. Subsequently, it was applied to a real engine airfoil at typical design conditions. A discussion of the features of the airfoil heat transfer distribution is included.

scholarly journals Heat Transfer Predictions for Two Turbine Nozzle Geometries at High Reynolds and Mach Numbers

1997 ◽  
Vol 119 (2) ◽  
pp. 270-283 ◽  
Author(s):  
R. J. Boyle ◽  
R. Jackson
Keyword(s):  
Heat Transfer ◽  
Turbulence Modeling ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Gas Temperature ◽  
Algebraic Models ◽  
Pressure Distributions ◽  
Nozzle Geometries ◽  
High Reynolds ◽  
Computational Analyses

Predictions of turbine vane and endwall heat transfer and pressure distributions are compared with experimental measurements for two vane geometries. The differences in geometries were due to differences in the hub profile, and both geometries were derived from the design of a high rim speed turbine (HRST). The experiments were conducted in the Isentropic Light Piston Facility (ILPF) at Pyestock at a Reynolds number of 5.3 x 106, a Mach number of 1.2, and a wall-to-gas temperature ratio of 0.66. Predictions are given for two different steady-state three-dimensional Navier–Stokes computational analyses. C-type meshes were used, and algebraic models were employed to calculate the turbulent eddy viscosity. The effects of different turbulence modeling assumptions on the predicted results are examined. Comparisons are also given between predicted and measured total pressure distributions behind the vane. The combination of realistic engine geometries and flow conditions proved to be quite demanding in terms of the convergence of the CFD solutions. An appropriate method of grid generation, which resulted in consistently converged CFD solutions, was identified.

Nonaxisymmetric Three-Dimensional Stagnation-Point Flow and Heat Transfer on a Flat Plate

2009 ◽  
Vol 131 (7) ◽  
Author(s):  
Ali Shokrgozar Abbassi ◽  
Asghar Baradaran Rahimi
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Flat Plate ◽  
Stagnation Point ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Stagnation Point Flow ◽  
Navier Stokes ◽  
Dimensional Flow ◽  
Flow And Heat Transfer

The existing solutions of Navier–Stokes and energy equations in the literature regarding the three-dimensional problem of stagnation-point flow either on a flat plate or on a cylinder are only for the case of axisymmetric formulation. The only exception is the study of three-dimensional stagnation-point flow on a flat plate by Howarth (1951, “The Boundary Layer in Three-Dimensional Flow—Part II: The Flow Near Stagnation Point,” Philos. Mag., 42, pp. 1433–1440), which is based on boundary layer theory approximation and zero pressure assumption in direction of normal to the surface. In our study the nonaxisymmetric three-dimensional steady viscous stagnation-point flow and heat transfer in the vicinity of a flat plate are investigated based on potential flow theory, which is the most general solution. An external fluid, along z-direction, with strain rate a impinges on this flat plate and produces a two-dimensional flow with different components of velocity on the plate. This situation may happen if the flow pattern on the plate is bounded from both sides in one of the directions, for example x-axis, because of any physical limitation. A similarity solution of the Navier–Stokes equations and energy equation is presented in this problem. A reduction in these equations is obtained by the use of appropriate similarity transformations. Velocity profiles and surface stress-tensors and temperature profiles along with pressure profile are presented for different values of velocity ratios, and Prandtl number.

Navier–Stokes Analysis of Turbine Blade Heat Transfer and Performance

1992 ◽  
Vol 114 (4) ◽  
pp. 795-806 ◽  
Author(s):  
D. J. Dorney ◽  
R. L. Davis
Keyword(s):  
Heat Transfer ◽  
Turbine Blade ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Approximate Factorization ◽  
Absolute Level ◽  
Flow Angle ◽  
And Performance

A three-dimensional Navier–Stokes analysis of heat transfer and aerodynamic performance is presented for a low-speed linear turbine cascade. The numerical approach used in this analysis consists of an alternate-direction, implicit, approximate-factorization, time-marching technique. An objective of this investigation has been to establish the computational grid density requirements necessary to predict blade surface and endwall heat transfer accurately, as well as the exit plane aerodynamic total pressure loss and flow angle distributions. In addition, a study has been performed to determine the importance of modeling transition as well as a viable implementation strategy for the three-dimensional turbulence model in the turbine blade passage. Results are presented demonstrating that the present procedure can accurately predict three-dimensional turbine blade heat transfer as well as the absolute level and spanwise distribution of aerodynamic performance quantities.

scholarly journals Prediction of Film Cooling on Gas Turbine Airfoils

1994 ◽  
Author(s):  
Vijay K. Garg ◽  
Raymond E. Gaugler
Keyword(s):  
Heat Transfer ◽  
Film Cooling ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Analysis Tool ◽  
Airfoil Surface ◽  
Flow And Heat Transfer ◽  
Head Cooling ◽  
Control Volumes ◽  
Turbine Airfoils

A three-dimensional Navier-Stokes analysis tool has been developed In order to study the effect of film cooling on the flow and heat transfer characteristics of actual turbine airfoils. An existing code (Amone et al., 1991) has been modified for the purpose. The code is an explicit, multigrid, ceil-centered, finite volume code with an algebraic turbulence model. Eigenvalue scaled artificial dissipation and variable-coefficient implicit residual smoothing are used with a full-multigrid technique. Moreover, Mayle’s transition criterion (Mayle, 1991) is used. The effects of film cooling have been incorporated into the code in the form of appropriate boundary conditions at the hole locations on the airfoil surface. Each hole exit is represented by several control volumes, thus providing an ability to study the effect of hole shape on the film-cooling characteristics. Comparison with mid-span experimental data for four and nine rows of cooling holes is fair. The computations, however, show a strong spanwise variation of the heat transfer coefficient on the airfoil surface, specially when the shower-head cooling holes are on.

scholarly journals Heat Transfer Predictions for Two Turbine Nozzle Geometries at High Reynolds and Mach Numbers

1995 ◽  
Author(s):  
R. J. Boyle ◽  
R. Jackson
Keyword(s):  
Heat Transfer ◽  
Turbulence Modeling ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Gas Temperature ◽  
Algebraic Models ◽  
Pressure Distributions ◽  
Nozzle Geometries ◽  
High Reynolds ◽  
Computational Analyses

Predictions of turbine vane and endwall heat transfer and pressure distributions are compared with experimental measurements for two vane geometries. The differences in geometries were due to differences in the hub profile, and both geometries were derived from the design of a high rim speed turbine (HRST). The experiments were conducted in the Isentropic Light Piston Facility (ILPF) at Pyestock at a Reynolds No. of 5.3 × 106, a Mach No. of 1.2, and a wall-to-gas temperature ratio of 0.66. Predictions are given for two different steady state three-dimensional Navier-Stokes computational analyses. C-type meshes were used, and algebraic models were employed to calculate the turbulent eddy viscosity. The effects of different turbulence modeling assumptions on the predicted results are examined. Comparisons are also given between predicted and measured total pressure distributions behind the vane. The combination of realistic engine geometries and flow conditions proved to be quite demanding in terms of the convergence of the CFD solutions. An appropriate method of grid generation, which resulted in consistently converged CFD solutions, was identified.

CFD Heat Transfer Predictions for a High-Pressure Turbine Stage

2004 ◽  
Author(s):  
James A. Tallman
Keyword(s):  
Heat Transfer ◽  
High Pressure ◽  
Turbulence Modeling ◽  
Pressure Ratio ◽  
Numerical Procedure ◽  
Navier Stokes ◽  
Turbine Stage ◽  
Temperature Ratio ◽  
High Pressure Turbine ◽  
Computational Fluid Dynamics Cfd

Computational Fluid Dynamics (CFD) was used to predict the turbine airfoil heat transfer for the high-pressure vane and high-pressure blade of a modern, one and one half stage turbine at its correct scale. Airfoil pressure and heat transfer measurements were recently obtained for the turbine in a transient shock tunnel facility, which allows for the replication of the actual engine turbine’s design corrected speed, pressure ratio, and gas-to-metal temperature ratio. A 3-D, compressible, Reynolds-averaged Navier-Stokes CFD solver with k-ω turbulence modeling was used for the CFD predictions. The turbulence model’s implementation into the numerical procedure was modified slightly, in order to better capture the model’s intended near-wall behavior and resolve the heat transfer prediction. Both the high-pressure vane and high-pressure blade were computed as steady-state flows and for two different turbine Reynolds number settings. Overall, the predictions compare very favorably with the measurement for both pressure and heat transfer at the mid-span location. A discussion of the features of the airfoil heat transfer distribution is included.

Computational Analysis of Heat Transfer Enhancement in Square Ducts With V-Shaped Ribs: Turbine Blade Cooling

2005 ◽  
Vol 127 (4) ◽  
pp. 425-433 ◽  
Author(s):  
R. Jia ◽  
B. Sunde´n ◽  
M. Faghri
Keyword(s):  
Heat Transfer ◽  
Fluid Flow ◽  
Heat Transfer Enhancement ◽  
Turbulence Modeling ◽  
Experimental Studies ◽  
Numerical Approach ◽  
Navier Stokes ◽  
Transfer Enhancement ◽  
Transfer Coefficients ◽  
Sampling Points

Experimental studies have revealed that both downstream and upstream pointing V-shaped ribs result in more heat transfer enhancement than transverse straight ribs in ducts. However, based on the available experimental results, contradiction exists whether the upstream or the downstream pointing V-shaped ribs orientation is superior for better enhancement in heat transfer. Further investigations are thus needed concerning the heat transfer and fluid flow phenomena in ducts with V-shaped ribs to clarify this. In the present investigation a numerical approach is taken and the heat and fluid flow is numerically simulated by a multi-block parallel 3D solver. For turbulence modeling, the v2¯ f-kε model is employed but results from previous EASM calculations are also considered in analyzing and attempting to understand the various experimental data. Large eddy simulations (LES) are also carried to evaluate the accuracy and reliability of the results of Reynolds-averaged Navier-Stokes (RANS) methods and to understand the underlying physical phenomena. It is suggested that the discrepancy between the various experiments most probably is due to the measurement methods, or the number of sampling points. With the TC (thermocouples) technique, a few sampling points are not sufficient to represent the heat transfer behavior in V-shaped ribs, due to the uneven distribution of the heat transfer coefficients.

scholarly journals A Code for Simulating Heat Transfer in Turbulent Channel Flow

Mathematics ◽  
2021 ◽  
Vol 9 (7) ◽  
pp. 756
Author(s):  
Federico Lluesma-Rodríguez ◽  
Francisco Álcantara-Ávila ◽  
María Jezabel Pérez-Quiles ◽  
Sergio Hoyas
Keyword(s):  
Heat Transfer ◽  
Stokes Equations ◽  
Three Dimensional ◽  
Turbulent Channel Flow ◽  
Passive Scalar ◽  
Direct Numerical Simulations ◽  
Time Dependent ◽  
Navier Stokes ◽  
Thermal Flow ◽  
Navier Stokes Equations

One numerical method was designed to solve the time-dependent, three-dimensional, incompressible Navier–Stokes equations in turbulent thermal channel flows. Its originality lies in the use of several well-known methods to discretize the problem and its parallel nature. Vorticy-Laplacian of velocity formulation has been used, so pressure has been removed from the system. Heat is modeled as a passive scalar. Any other quantity modeled as passive scalar can be very easily studied, including several of them at the same time. These methods have been successfully used for extensive direct numerical simulations of passive thermal flow for several boundary conditions.

scholarly journals Modelling of Applied Magnetic Field and Thermal Radiations Due to the Stretching of Cylinder

Processes ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 1077
Author(s):  
Muhammad Tamoor ◽  
Muhammad Kamran ◽  
Sadique Rehman ◽  
Aamir Farooq ◽  
Rewayat Khan ◽  
...  
Keyword(s):  
Heat Transfer ◽  
Fluid Velocity ◽  
Three Dimensional ◽  
Numerical Approach ◽  
Skin Friction Coefficient ◽  
Physical Parameters ◽  
Boundary Layer Equations ◽  
Convective Parameter ◽  
Momentum And Heat Transfer ◽  
Dimensional Boundary

In this study, a numerical approach was adopted in order to explore the analysis of magneto fluid in the presence of thermal radiation combined with mixed convective and slip conditions. Using the similarity transformation, the axisymmetric three-dimensional boundary layer equations were reduced to a self-similar form. The shooting technique, combined with the Range–Kutta–Fehlberg method, was used to solve the resulting coupled nonlinear momentum and heat transfer equations numerically. When physically interpreting the data, some important observations were made. The novelty of the present study lies in finding help to control the rate of heat transfer and fluid velocity in any industrial manufacturing processes (such as the cooling of metallic plates). The numerical results revealed that the Nusselt number decrease for larger Prandtl number, curvature, and convective parameters. At the same time, the skin friction coefficient was enhanced with an increase in both slip velocity and convective parameter. The effect of emerging physical parameters on velocity and temperature profiles for a nonlinear stretching cylinder has been thoroughly studied and analyzed using plotted graphs and tables.

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