Performance Improvement Through Indexing of Turbine Airfoils: Part 2—Numerical Simulation

1996 ◽  
Vol 118 (4) ◽  
pp. 636-642 ◽  
Author(s):  
L. W. Griffin ◽  
F. W. Huber ◽  
O. P. Sharma
Keyword(s):  
Performance Improvement ◽  
Space Shuttle ◽  
Computational Procedure ◽  
Cfd Simulations ◽  
Performance Improvements ◽  
Computational Fluid Dynamics Cfd ◽  
The Subject ◽  
Turbine Airfoils ◽  
Main Engine ◽  
Computational Analyses

An experimental/analytical study has been conducted to determine the performance improvements achievable by circumferentially indexing succeeding rows of turbine stator airfoils. A series of tests was conducted to experimentally investigate stator wake clocking effects on the performance of the space shuttle main engine (SSME) alternate turbopump development (ATD) fuel turbine test article (TTA). The results from this study indicate that significant increases in stage efficiency can be attained through application of this airfoil clocking concept. Details of the experiment and its results are documented in part 1 of this paper. In order to gain insight into the mechanisms of the performance improvement, extensive computational fluid dynamics (CFD) simulations were executed. The subject of the present paper is the initial results from the CFD investigation of the configurations and conditions detailed in part 1 of the paper. To characterize the aerodynamic environments in the experimental test series, two-dimensional, time-accurate, multistage, viscous analyses were performed at the TTA midspan. Computational analyses for five different circumferential positions of the first stage stator have been completed. Details of the computational procedure and the results are presented. The analytical results verify the experimentally demonstrated performance improvement and are compared with data whenever possible. Predictions of time-averaged turbine efficiencies as well as gas conditions throughout the flow field are presented. An initial understanding of the turbine performance improvement mechanism based on the results from this investigation is described.

Performance Improvement Through Indexing of Turbine Airfoils: Part 2 — Numerical Simulation

1995 ◽  
Author(s):  
Lisa W. Griffin ◽  
Frank W. Huber ◽  
Om P. Sharma
Keyword(s):  
Performance Improvement ◽  
Space Shuttle ◽  
Computational Procedure ◽  
Cfd Simulations ◽  
Performance Improvements ◽  
Computational Fluid Dynamics Cfd ◽  
The Subject ◽  
Turbine Airfoils ◽  
Main Engine ◽  
Computational Analyses

An experimental/analytical study has been conducted to determine the performance improvements achievable by circumferentially indexing succeeding rows of turbine stator airfoils. A series of tests was conducted to experimentally investigate stator wake clocking effects on the performance of the space shuttle main engine (SSME) alternate turbopump development (ATD) fuel turbine test article (TTA). The results from this study indicate that significant increases in stage efficiency can be attained through application of this airfoil clocking concept. Details of the experiment and its results are documented in part 1 of this paper. In order to gain insight into the mechanisms of the performance improvement, extensive computational fluid dynamics (CFD) simulations were executed. The subject of the present paper is the initial results from the CFD investigation of the configurations and conditions detailed in part 1 of the paper. To characterize the aerodynamic environments in the experimental test series, two-dimensional (2D), time-accurate, multistage, viscous analyses were performed at the TTA midspan. Computational analyses for five different circumferential positions of the first stage stator have been completed. Details of the computational procedure and the results are presented. The analytical results verify the experimentally demonstrated performance improvement and are compared with data whenever possible. Predictions of time-averaged turbine efficiencies as well as gas conditions throughout the flow field are presented. An initial understanding of the turbine performance improvement mechanism based on the results from this investigation is described.

Performance Improvement Through Indexing of Turbine Airfoils: Part 1 — Experimental Investigation

1995 ◽  
Author(s):  
F. W. Huber ◽  
P. D. Johnson ◽  
O. P. Sharma ◽  
J. B. Staubach ◽  
S. W. Gaddis
Keyword(s):  
Performance Improvement ◽  
Space Shuttle ◽  
Computational Procedure ◽  
Analytical Investigation ◽  
Test Facility ◽  
Test Article ◽  
Performance Improvements ◽  
Turbine Stator ◽  
Turbine Performance ◽  
Cfd Analyses

This paper describes the results of a study to determine the performance improvements achievable by circumferentially indexing successive rows of turbine stator airfoils. An experimental / analytical investigation has been completed which indicates significant stage efficiency increases can be attained through application of this airfoil clocking concept. A series of tests was conducted at the National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) to experimentally investigate stator wake clocking effects on the performance of the Space Shuttle Main Engine Alternate Fuel Turbopump Turbine Test Article. Extensive time-accurate Computational Fluid Dynamics (CFD) simulations have been completed for the test configurations. The CFD results provide insight into the performance improvement mechanism. Part one of this paper describes details of the test facility, rig geometry, instrumentation, and aerodynamic operating parameters. Results of turbine testing at the aerodynamic design point are presented for six circumferential positions of the first stage stator, along with a description of the initial CFD analyses performed for the test article. It should be noted that first vane positions 1 and 6 produced identical first to second vane indexing. Results obtained from off-design testing of the “best” and “worst” stator clocking positions, and testing over a range of Reynolds numbers are also presented. Part two of this paper describes the numerical simulations performed in support of the experimental test program described in part one. Time-accurate Navier-Stokes flow analyses have been completed for the five different turbine stator positions tested. Details of the computational procedure and results are presented. Analysis results include predictions of instantaneous and time-average mid-span airfoil and turbine performance, as well as gas conditions throughout the flow field. An initial understanding of the turbine performance improvement mechanism is described.

Performance Improvement Through Indexing of Turbine Airfoils: Part 1—Experimental Investigation

1996 ◽  
Vol 118 (4) ◽  
pp. 630-635 ◽  
Author(s):  
F. W. Huber ◽  
P. D. Johnson ◽  
O. P. Sharma ◽  
J. B. Staubach ◽  
S. W. Gaddis
Keyword(s):  
Performance Improvement ◽  
Space Shuttle ◽  
Computational Procedure ◽  
Analytical Investigation ◽  
Test Facility ◽  
Test Article ◽  
Performance Improvements ◽  
Turbine Stator ◽  
Turbine Performance ◽  
Cfd Analyses

This paper describes the results of a study to determine the performance improvements achievable by circumferentially indexing successive rows of turbine stator airfoils. An experimental/analytical investigation has been completed that indicates significant stage efficiency increases can be attained through application of this airfoil clocking concept. A series of tests was conducted at the National Aeronautics and Space Administration’s (NASA) Marshall Space Flight Center (MSFC) to experimentally investigate stator wake clocking effects on the performance of the Space Shuttle Main Engine Alternate Fuel Turbopump Turbine Test Article. Extensive time-accurate Computational Fluid Dynamics (CFD) simulations have been completed for the test configurations. The CFD results provide insight into the performance improvement mechanism. Part one of this paper describes details of the test facility, rig geometry, instrumentation, and aerodynamic operating parameters. Results of turbine testing at the aerodynamic design point are presented for six circumferential positions of the first stage stator, along with a description of the initial CFD analyses performed for the test article. It should be noted that first vane positions 1 and 6 produced identical first to second vane indexing. Results obtained from off-design testing of the “best” and “worst” stator clocking positions, and testing over a range of Reynolds numbers are also presented. Part two of this paper describes the numerical simulations performed in support of the experimental test program described in part one. Time-accurate Navier–Stokes flow analyses have been completed for the five different turbine stator positions tested. Details of the computational procedure and results are presented. Analysis results include predictions of instantaneous and time-average midspan airfoil and turbine performance, as well as gas conditions throughout the flow field. An initial understanding of the turbine performance improvement mechanism is described.

Experimental and Theoretical Comparison of Two Swirl Brake Designs

2000 ◽  
Vol 123 (2) ◽  
pp. 353-358 ◽  
Author(s):  
K. K. Nielsen ◽  
D. W. Childs ◽  
C. M. Myllerup
Keyword(s):  
Space Shuttle ◽  
Theoretical Data ◽  
Superior Performance ◽  
Swirl Ratio ◽  
Strong Separation ◽  
Inlet Swirl ◽  
Computational Fluid Dynamics Cfd ◽  
Brake Performance ◽  
Main Engine ◽  
Better Than

Experimental and theoretical data are presented for two interchangeable swirl brakes designed in connection with the Space Shuttle Main Engine (SSME) Alternate Turbopump Development (ATD) High-Pressure Fuel Turbopump (HPFTP) program. The experimental data includes rotordynamic data for a extensive variation of test variables. Comparison of the swirl brake performance revealed that a nonaerodynamic swirl brake design proved as efficient and at times better than an aerodynamic design. For this reason a theoretical investigation using computational fluid dynamics (CFD) was recently carried out. This modeling focused on predicting the seal inlet swirl ratio which is the primary swirl brake performance parameter. The nonaerodynamic swirl brake showed superior performance for a variety of test variable conditions. Strong separation vortices within the swirl vanes are the main reason for this finding.

Comparison of Two-Dimensional and Three-Dimensional Turbine Airfoils in Combination With Nonaxisymmetric Endwall Contouring

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Tobias W. Zimmermann ◽  
Oliver Curkovic ◽  
Manfred Wirsum ◽  
Andrew Fowler ◽  
Kush Patel
Keyword(s):  
Three Dimensional ◽  
Cfd Simulations ◽  
Positive Effects ◽  
Beneficial Impact ◽  
Flow Phenomena ◽  
Computational Fluid Dynamics Cfd ◽  
Endwall Contouring ◽  
Turbine Airfoils ◽  
End Wall ◽  
Constant Section

Tangential endwall contouring (TEWC) is intended to improve the turbomachinery blading efficiency. This paper summarizes the experimental and numerical investigation of a test turbine with endwall contoured vanes and blades. Constant section (2D) airfoils as well as optimized compound lean (3D) high pressure steam turbine blading in baseline and endwall contoured configurations have been examined. Brush seals (BSs) are implemented within the casing sided cavities to minimize the leakage flow near the tip endwalls, where the contouring is also applied. The pressure and temperature data that are recorded in three axial measuring planes are plotted to visualize the change in flow structure. This shows that the efficiency is increased for 2D airfoils by means of endwall contouring. However, the efficiency of the first stage suffers, and the endwall contouring is still beneficial for the overall performance of the engine. Both phenomena (an efficiency loss in stage one and an improvement of the performance in stage two) have also been measured for the optimized 3D configurations; thus, it can be expected that the endwall contouring has also a beneficial impact on the performance of multirow turbines. The numerical investigations demonstrate in detail, how the secondary flow phenomena are influenced by end-wall contouring and a description of the changes in vortex formations as well as blade loading are given for the various configurations. It has been found that for steady computational fluid dynamics (CFD) simulations the use of stage interfaces suppresses the positive effects of the endwall contour onto the downstream blade row.

Experimental and Theoretical Comparison of Two Swirl Brake Designs

2000 ◽  
Author(s):  
K. K. Nielsen ◽  
D. W. Childs ◽  
C. M. Myllerup
Keyword(s):  
Space Shuttle ◽  
Theoretical Data ◽  
Superior Performance ◽  
Swirl Ratio ◽  
Strong Separation ◽  
Inlet Swirl ◽  
Computational Fluid Dynamics Cfd ◽  
Brake Performance ◽  
Main Engine ◽  
Better Than

Experimental and theoretical data are presented for two interchangeable swirl brakes designed in connection with the Space Shuttle Main Engine (SSME) Alternate Turbopump Development (ATD) High-Pressure Fuel Turbopump (HPFTP) program. The experimental data includes rotordynamic data for a extensive variation of test variables. Comparison of the swirl brake performance revealed that a non-aerodynamic swirl brake design proved as efficient and at times better than an aerodynamic design. For this reason a theoretical investigation using Computational Fluid Dynamics (CFD) was recently carried out. This modeling focused on predicting the seal inlet swirl ratio which is the primary swirl brake performance parameter. The non-aerodynamic swirl brake showed superior performance for a variety of test variable conditions. Strong separation vortices within the swirl vanes are the main reason for this finding.

Comparative Study Between Structured and Unstructured Meshes Applied in Turbopump’s Hydraulic Turbine

2020 ◽  
Author(s):  
Daniel da Silva Tonon ◽  
Jesuíno Takachi Tomita ◽  
Ezio Castejon Garcia ◽  
Cleverson Bringhenti ◽  
Rubén Bruno Díaz ◽  
...  
Keyword(s):  
Space Shuttle ◽  
Hydraulic Turbine ◽  
Unstructured Meshes ◽  
Tip Clearance ◽  
Navier Stokes ◽  
Axial Turbine ◽  
Advantages And Disadvantages ◽  
Unstructured Tetrahedral Meshes ◽  
Computational Fluid Dynamics Cfd ◽  
Main Engine

Abstract The aim of this work is the evaluation of different mesh types applied in turbomachines area, in this case in an axial turbine stage used in turbopumps (TP) applications. The tip clearance region was considered in this study because it has high influence in turbomachines performance. Due to the complexity of the tip clearance region, structured mesh generation is not always feasible, therefore it is necessary to generate unstructured meshes that allow flow calculation through Computational Fluid Dynamics (CFD) techniques. The use of different mesh type is an interesting topic when different rotor tip geometries are evaluated, in which the desensitization methods are applied. In this work, only the common flat-tip was consider. Thus, as a first step, unstructured tetrahedral meshes (with prismatic layers close to the surfaces) with different y+ values were generated. After this, turbulent 3-D flow calculations were performed at design and off design conditions, based con Reynolds Averaged Navier-Stokes (RANS) equations. The methodology used is to present in a didactic way, for under and graduate students, the advantages and disadvantages of the unstructured mesh in relation to the structured one, already used in previous research. Unstructured meshes were generated using ICEM software (ANSYS), while structured ones were generated using AxCent software developed by CONCEPTS NREC. The machine under study is the first stage of the hydraulic axial turbine used in the Low Pressure Oxidizer Turbopump (LPOTP) of the Space Shuttle Main Engine (SSME), considering 3.0% tip clearance configuration relative to blade height. All simulations were done using CFX program (ANSYS). The result shows the comparison between the two mesh types considering the difficulty and time generation, discretization quality, effect of y+ parameter variation on flowfield, simulation time, and stage performance parameters calculation for different operating points.

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