A validation of a Navier-Stokes 2D solver for transonic turbine cascade flows

1989 ◽  
Author(s):  
S. COLANTUONI ◽  
A. TERLIZZI ◽  
F. GRASSO
Keyword(s):  
Navier Stokes ◽  
Turbine Cascade ◽  
Transonic Turbine

scholarly journals Three-Dimensional Navier–Stokes Analysis and Redesign of an Imbedded Bellmouth Nozzle in a Turbine Cascade Inlet Section

1996 ◽  
Vol 118 (3) ◽  
pp. 529-535 ◽  
Author(s):  
P. W. Giel ◽  
J. R. Sirbaugh ◽  
I. Lopez ◽  
G. J. Van Fossen
Keyword(s):  
Three Dimensional ◽  
Navier Stokes ◽  
Experimental Measurements ◽  
Inlet Section ◽  
Turbine Cascade ◽  
Blade Cascade ◽  
Inlet Geometry ◽  
Computational Fluid Dynamics Cfd ◽  
Transonic Turbine ◽  
Flow Nonuniformity

Experimental measurements in the inlet of a transonic turbine blade cascade showed unacceptable pitchwise flow nonuniformity. A three-dimensional, Navier–Stokes computational fluid dynamics (CFD) analysis of the imbedded bellmouth inlet in the facility was performed to identify and eliminate the source of the flow nonuniformity. The blockage and acceleration effects of the blades were accounted for by specifying a periodic static pressure exit condition interpolated from a separate three-dimensional Navier–Stokes CFD solution of flow around a single blade in an infinite cascade. Calculations of the original inlet geometry showed total pressure loss regions consistent in strength and location to experimental measurements. The results indicate that the distortions were caused by a pair of streamwise vortices that originated as a result of the interaction of the flow with the imbedded bellmouth. Computations were performed for an inlet geometry that eliminated the imbedded bellmouth by bridging the region between it and the upstream wall. This analysis indicated that eliminating the imbedded bellmouth nozzle also eliminates the pair of vortices, resulting in a flow with much greater pitchwise uniformity. Measurements taken with an installed redesigned inlet verify that the flow nonuniformity has indeed been eliminated.

Inverse Design of and Experimental Measurements in a Double-Passage Transonic Turbine Cascade Model

2005 ◽  
Vol 127 (3) ◽  
pp. 619-626 ◽  
Author(s):  
G. M. Laskowski ◽  
A. Vicharelli ◽  
G. Medic ◽  
C. J. Elkins ◽  
J. K. Eaton ◽  
...  
Keyword(s):  
Stokes Equations ◽  
Design Procedure ◽  
Cascade Model ◽  
Inverse Design ◽  
Navier Stokes ◽  
Turbine Cascade ◽  
Flow Conditions ◽  
Navier Stokes Equations ◽  
Attached Flow ◽  
Transonic Turbine

A new transonic turbine cascade model that accurately produces infinite cascade flow conditions with minimal compressor requirements is presented. An inverse design procedure using the Favre-averaged Navier-Stokes equations and k‐ε turbulence model based on the method of steepest descent was applied to a geometry consisting of a single turbine blade in a passage. For a fixed blade geometry, the passage walls were designed such that the surface isentropic Mach number (SIMN) distribution on the blade in the passage matched the SIMN distribution on the blade in an infinite cascade, while maintaining attached flow along both passage walls. An experimental rig was built that produces realistic flow conditions, and also provides the extensive optical access needed to obtain detailed particle image velocimetry measurements around the blade. Excellent agreement was achieved between computational fluid dynamics (CFD) of the infinite cascade SIMN, CFD of the designed double passage SIMN, and the measured SIMN.

Navier–Stokes Solution for Steady Two-Dimensional Transonic Cascade Flows

1988 ◽  
Vol 110 (3) ◽  
pp. 339-346 ◽  
Author(s):  
O. K. Kwon
Keyword(s):  
Stokes Equations ◽  
Solution Procedure ◽  
Curvilinear Coordinates ◽  
Navier Stokes ◽  
Two Dimensional ◽  
Turbine Cascade ◽  
Navier Stokes Equations ◽  
Time Marching ◽  
Transonic Turbine ◽  
Transonic Cascade

A robust, time-marching Navier–Stokes solution procedure based on the explicit hopscotch method is presented for solution of steady, two-dimensional, transonic turbine cascade flows. The method is applied to the strong conservation form of the unsteady Navier–Stokes equations written in arbitrary curvilinear coordinates. Cascade flow solutions are obtained on an orthogonal, body-conforming “O” grid with the standard k–ε turbulence model. Computed results are presented and compared with experimental data.

scholarly journals Simulation of Trailing Edge Vortex Shedding in a Transonic Turbine Cascade

1996 ◽  
Author(s):  
Tom C. Currie ◽  
William E. Carscallen
Keyword(s):  
Vortex Shedding ◽  
Navier Stokes ◽  
Numerical Dissipation ◽  
Turbine Cascade ◽  
Trailing Edge ◽  
Edge Vortex ◽  
Transonic Turbine ◽  
Exit Mach Number ◽  
Good Agreement

Mid-span losses in the NRC transonic turbine cascade peak at an exit Mach number (M2) of ∼1.0 and then decrease by ∼40% as M2 is increased to the design value of 1.16. Since recent experimental results suggest that the decrease may be related to a reduction in the intensity of trailing edge vortex shedding, both steady and unsteady quasi-3D Navier-Stokes simulations have been performed with a highly refined (unstructured) grid to determine the role of shedding. Predicted shedding frequencies are in good agreement with experiment, indicating the blade boundary layers and trailing edge separated free shear layers have been modelled satisfactorily, but the agreement for base pressures is relatively poor, probably due largely to false entropy created downstream of the trailing edge by numerical dissipation. The results emphasize the importance of accounting for the effect of vortex shedding on base pressure and loss.

scholarly journals Viscous Flow Computations in Turbomachine Cascades

1990 ◽  
Author(s):  
P.-A. Chevrin ◽  
C. Vuillez
Keyword(s):  
Stokes Equations ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Turbine Cascade ◽  
Compressor Cascade ◽  
Navier Stokes Equations ◽  
Transonic Compressor ◽  
Different Types ◽  
Time Marching ◽  
Transonic Turbine

Accurate prediction of the flow in turbomachinery requires numerical solution of the Navier-Stokes equations. A two-dimensional Navier-Stokes solver developed at ONERA for the calculation of the flow in turbine and compressor cascades was adapted at SNECMA to run on different types of grid. The solver uses an explicit, time-marching, finite-volume technique, with a multigrid acceleration scheme. A multi-domain approach is used to handle difficulties due to the geometry of the flow. An H-C grid was used in the calculations. Two turbulence models, based on the mixing length approach, were used. The flow in a transonic compressor cascade, a subsonic and a transonic turbine cascade were computed. Comparison with experiments is presented.

scholarly journals Three-Dimensional Navier-Stokes Analysis and Redesign of an Imbedded Bellmouth Nozzle in a Turbine Cascade Inlet Section

1994 ◽  
Author(s):  
P. W. Giel ◽  
J. R. Sirbaugh ◽  
I. Lopez ◽  
G. J. Van Fossen
Keyword(s):  
Static Pressure ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Experimental Measurements ◽  
Inlet Section ◽  
Turbine Cascade ◽  
Blade Cascade ◽  
Inlet Geometry ◽  
Computational Fluid Dynamics Cfd ◽  
Transonic Turbine

Experimental measurements in the inlet of a transonic turbine blade cascade showed unacceptable pitchwise flow non-uniformity. A three-dimensional, Navier-Stokes computational fluid dynamics (CFD) analysis of the imbedded bellmouth inlet in the facility was performed to identify and eliminate the source of the flow non-uniformity. The blockage and acceleration effects of the blades were accounted for by specifying a periodic static pressure exit condition interpolated from a separate three-dimensional Navier-Stokes CFD solution of flow around a single blade in an infinite cascade. Calculations of the original inlet geometry showed total pressure loss regions consistent in strength and location to experimental measurements. The results indicate that the distortions were caused by a pair of streamwise vortices that originated as a result of the interaction of the flow with the imbedded bellmouth. Computations were performed for an inlet geometry which eliminated the imbedded bellmouth by bridging the region between it and the upstream wall. This analysis indicated that eliminating the imbedded bellmouth nozzle also eliminates the pair of vortices, resulting in a flow with much greater pitchwise uniformity. Measurements taken with an installed redesigned inlet verify that the flow non-uniformity has indeed been eliminated.

Simulation of Trailing Edge Vortex Shedding in a Transonic Turbine Cascade

1998 ◽  
Vol 120 (1) ◽  
pp. 10-19 ◽  
Author(s):  
T. C. Currie ◽  
W. E. Carscallen
Keyword(s):  
Vortex Shedding ◽  
Three Dimensional ◽  
Navier Stokes ◽  
Numerical Dissipation ◽  
Turbine Cascade ◽  
Trailing Edge ◽  
Edge Vortex ◽  
Transonic Turbine ◽  
Exit Mach Number

Midspan losses in the NRC transonic turbine cascade peak at an exit Mach number (M2) of ~1.0 and then decrease by ~40 percent as M2 is increased to the design value of 1.16. Since recent experimental results suggest that the decrease may be related to a reduction in the intensity of trailing edge vortex shedding, both steady and unsteady quasi-three-dimensional Navier–Stokes simulations have been performed with a highly refined (unstructured) grid to determine the role of shedding. Predicted shedding frequencies are in good agreement with experiment, indicating the blade boundary layers and trailing edge separated free shear layers have been modeled satisfactorily, but the agreement for base pressures is relatively poor, probably due largely to false entropy created downstream of the trailing edge by numerical dissipation. The results nonetheless emphasize the importance of accounting for the effect of vortex shedding on base pressure and loss.

scholarly journals Navier-Stokes Computations for Turbulent Flow Predictions in Transonic Turbine Cascade Using a Zonal Approach

1993 ◽  
Author(s):  
J. J. Yeuan ◽  
A. Hamed ◽  
W. Tabakoff
Keyword(s):  
Turbulent Flow ◽  
Viscous Flow ◽  
Turbine Blade ◽  
Turbulence Models ◽  
Navier Stokes ◽  
Turbine Cascade ◽  
Flow Conditions ◽  
Numerical Errors ◽  
Flow Through ◽  
Transonic Turbine

Numerical results are presented for viscous flow through a transonic turbine cascade using different turbulence models and H-type grids. The explicit Navier-Stokes solver used in the solution was developed with an option of conservative zonal approach for interpolation across the periodic boundaries with minimum numerical errors. This approach allows the use of a grid that is more orthogonal and less skewed which leads to higher accuracy in the prediction of turbine blade performance. The results obtained with an algebraic and two equation turbulence models, and with two types of H grids are compared at two different flow conditions.

scholarly journals Secondary Flows in a Transonic Cascade: Validation of a 3-D Navier-Stokes Code

1992 ◽  
Author(s):  
F. Bassi ◽  
M. Savini
Keyword(s):  
Characteristic Feature ◽  
Secondary Flow ◽  
Finite Volume ◽  
Secondary Flows ◽  
Navier Stokes ◽  
Turbine Cascade ◽  
Blade Passage ◽  
Transonic Turbine ◽  
Transonic Cascade ◽  
Insight Into

In this work is presented a finite volume full 3-D Navier-Stokes solver suitable for turbulent turbomachinery computations. The code is applied to the analysis of the secondary flow patterns in a transonic turbine cascade at three different isentropic outlet Mach numbers; namely 0.50, 1.02, 1.38. Detailed measurements obtained in four planes downstream of the trailing edge allow for comparison of losses, flow angles, vorticity and hence for a deep evaluation of the accuracy of the numerical results. Moreover the code is used to gain insight into the formation and the evolution of secondary flows inside the blade passage, into the generation of losses and into characteristic feature of these flows hard to detect experimentally. All the above mentioned aspects are examined and discussed as well as the influence of compressibility, giving thus a precise picture of secondary flows in the transonic regime.

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