Aerodynamic Investigations of a Variable Inlet Guide Vane With Symmetric Profile

2014 ◽  
Author(s):  
David Händel ◽  
Reinhard Niehuis ◽  
Uwe Rockstroh
Keyword(s):  
Boundary Layer ◽  
High Speed ◽  
Guide Vane ◽  
Reynolds Numbers ◽  
Boundary Layer Transition ◽  
Inlet Guide Vane ◽  
Experimental Investigations ◽  
Wide Range ◽  
Variable Inlet Guide Vane ◽  
Symmetric Profile

In order to determine the aerodynamic behavior of a Variable Inlet Guide Vane as used in multishaft compressors, extensive experimental investigations with a 2D linear cascade have been conducted. All the experiments were performed at the High-Speed Cascade Wind Tunnel at the Institute of Jet Propulsion. They covered a wide range of Reynolds numbers and stagger angles as they occur in realistic turbomachines. Within this work at first the observed basic flow phenomena (loss development, overturning) will be explained. For the present special case of a symmetric profile and a constant decreasing chord length along the vane height, statements about different spanwise position can be made by investigating different Reynolds numbers. The focus of this paper is on the outflow of the VIGV along the vane height. Results for an open flow separation on the suction side are presented, too. Stall condition can be delayed by boundary layer control. This is done using a wire to trigger an early boundary layer transition. The outcomes of the trip wire measurement are finally discussed. The objective of this work is to evaluate the influence of the stagger angle and Reynolds number on the total pressure losses and the deviation angle. The results of the work presented here, gives a better insight of the efficient use of a VIGV.

The Influence of Turbulence on Wake Dispersion and Blade Row Interaction in an Axial Compressor

2005 ◽  
Author(s):  
Alan D. Henderson ◽  
Gregory J. Walker ◽  
Jeremy D. Hughes
Keyword(s):  
Boundary Layer ◽  
Guide Vane ◽  
Axial Compressor ◽  
Boundary Layer Transition ◽  
Inlet Guide Vane ◽  
Grid Turbulence ◽  
Layer Transition ◽  
Free Stream Turbulence ◽  
Hot Film ◽  
Blade Element

The influence of free-stream turbulence on wake dispersion and boundary layer transition processes has been studied in a 1.5-stage axial compressor. An inlet grid was used to produce turbulence characteristics typical of an embedded stage in a multistage machine. The grid turbulence strongly enhanced the dispersion of inlet guide vane (IGV) wakes. This modified the interaction of IGV and rotor wakes, leading to a significant decrease in periodic unsteadiness experienced by the downstream stator. These observations have important implications for the prediction of clocking effects in multistage machines. Boundary layer transition characteristics on the outlet stator were studied with a surface hot-film array. Observations with grid turbulence were compared with those for the natural low turbulence inflow to the machine. The transition behavior under low turbulence inflow conditions with the stator blade element immersed in the dispersed IGV wakes closely resembled the behavior with elevated grid turbulence. It is concluded that with appropriate alignment, the blade element behavior in a 1.5-stage axial machine can reliably indicate the blade element behavior of an embedded row in a multistage machine.

The Influence of Turbulence on Wake Dispersion and Blade Row Interaction in an Axial Compressor

2005 ◽  
Vol 128 (1) ◽  
pp. 150-157 ◽  
Author(s):  
Alan D. Henderson ◽  
Gregory J. Walker ◽  
Jeremy D. Hughes
Keyword(s):  
Boundary Layer ◽  
Guide Vane ◽  
Axial Compressor ◽  
Boundary Layer Transition ◽  
Inlet Guide Vane ◽  
Grid Turbulence ◽  
Layer Transition ◽  
Free Stream Turbulence ◽  
Hot Film ◽  
Blade Element

The influence of free-stream turbulence on wake dispersion and boundary layer transition processes has been studied in a 1.5-stage axial compressor. An inlet grid was used to produce turbulence characteristics typical of an embedded stage in a multistage machine. The grid turbulence strongly enhanced the dispersion of inlet guide vane (IGV) wakes. This modified the interaction of IGV and rotor wakes, leading to a significant decrease in periodic unsteadiness experienced by the downstream stator. These observations have important implications for the prediction of clocking effects in multistage machines. Boundary layer transition characteristics on the outlet stator were studied with a surface hot-film array. Observations with grid turbulence were compared with those for the natural low turbulence inflow to the machine. The transition behavior under low turbulence inflow conditions with the stator blade element immersed in the dispersed IGV wakes closely resembled the behavior with elevated grid turbulence. It is concluded that with appropriate alignment, the blade element behavior in a 1.5-stage axial machine can reliably indicate the blade element behavior of an embedded row in a multistage machine.

1999 Turbomachinery Committee Best Paper Award: Development of Advanced Compressor Airfoils for Heavy-Duty Gas Turbines— Part II: Experimental and Theoretical Analysis

1999 ◽  
Vol 122 (3) ◽  
pp. 406-414 ◽  
Author(s):  
Bernhard Ku¨sters ◽  
Heinz-Adolf Schreiber ◽  
Ulf Ko¨ller ◽  
Reinhard Mo¨nig
Keyword(s):  
Boundary Layer ◽  
Gas Turbines ◽  
Total Pressure ◽  
Reynolds Numbers ◽  
Boundary Layer Transition ◽  
Surface Boundary ◽  
Heavy Duty ◽  
High Reynolds Numbers ◽  
Wide Range ◽  
High Reynolds

In Part I of this paper a family of numerically optimized subsonic compressor airfoils for heavy-duty gas turbines, covering a wide range of flow properties, is presented. The objective of the optimization was to create profiles with a wide low loss incidence range. Therefore, design point and off-design performance had to be considered in an objective function. The special flow conditions in large-scale gas turbines have been taken into account by performing the numerical optimization procedure at high Reynolds numbers and high turbulence levels. The objective of Part II is to examine some of the characteristics describing the new airfoils, as well as to prove the reliability of the design process and the flow solver applied. Therefore, some characteristic members of the new airfoil series have been extensively investigated in the cascade wind tunnel of DLR cologne. Experimental and numerical results show profile Mach number distributions, total pressure losses, flow turning, and static pressure rise for the entire incidence range. The design goal with low losses and especially a wide operating range could be confirmed, as well as a mild stall behavior. Boundary layer development, particularly near stall condition, is discussed using surface flow visualization and the results of boundary layer calculations. An additional experimental study, using liquid crystal coating, provides necessary information on suction surface boundary-layer transition at high Reynolds numbers. Finally, results of Navier–Stokes simulations are presented that enlighten the total pressure loss development and flow turning behavior, especially at high incidence in relation to the results of the design tool. [S0889-504X(00)02602-7]

Investigation of the Effectiveness of Various Types of Boundary Layer Transition Elements of Low Reynolds Number Turbine Bladings

2004 ◽  
Author(s):  
Claus H. Sieverding ◽  
Carlo Bagnera ◽  
A. C. Boege ◽  
Juan A. Cordero Anto`n ◽  
Vincent Lue`re
Keyword(s):  
Boundary Layer ◽  
Guide Vane ◽  
Suction Side ◽  
Reynolds Numbers ◽  
Boundary Layer Separation ◽  
Boundary Layer Transition ◽  
Transition Elements ◽  
Layer Transition ◽  
Optimum Position ◽  
Low Reynolds

The paper describes an experimental investigation of the use of different types of boundary layer transition elements for the control of boundary layer separation at low Reynolds numbers. The tests are carried out in a low speed cascade tunnel for Reynolds numbers between 30000 and 200000. For convenience the author used an existing HP turbine guide vane with ∼63 degree turning. To obtain representative adverse pressure gradients as those existing on the rear suction side of highly loaded LP blades the tests are run at a pitch-to-chord ratio of 1. The transition elements include tripwires, single and double rows of spherical roughness elements, balloon type transition elements and a metal sheet actuated by shape memory alloy springs. The optimum position and height of the transition elements are obtained with systematic tests with the trip wire. All other elements are placed at the same position and have approximately the same height. As expected, the transition elements are very beneficial at low Re numbers but deteriorate the performance at high Re numbers. The advantages and drawbacks of the various configurations are discussed and suggestions for real turbine applications are made.

scholarly journals Development of Advanced Compressor Airfoils for Heavy-Duty Gas Turbines: Part II — Experimental and Theoretical Analysis

1999 ◽  
Author(s):  
Bernhard Küsters ◽  
Helnz-Adolf Schreiber ◽  
Ulf D. Köller ◽  
Reinhard Mönig
Keyword(s):  
Boundary Layer ◽  
Gas Turbines ◽  
Total Pressure ◽  
Reynolds Numbers ◽  
Boundary Layer Transition ◽  
Surface Boundary ◽  
Heavy Duty ◽  
High Reynolds Numbers ◽  
Wide Range ◽  
High Reynolds

In Part I of this paper a family of numerically optimized subsonic compressor airfoils for heavy-duty gas turbines, covering a wide range of flow properties, is presented. The objective of the optimization was 10 create profiles with a wide low loss incidence range. Therefore, design point and off-design performance had to be considered in an objective function. The special flow conditions in large scale gas turbines have been taken into account by performing the numerical optimization procedure at high Reynolds numbers and high turbulence levels. The objective of Part II is to examine some of the characteristics describing the new airfoils, as well as to prove the reliability of the design process and the flow solver applied. Therefore, some characteristic members of the new airfoil series have been extensively investigated in the cascade windtunnel of DLR Cologne. Experimental and numerical results show profile Mach number distributions, total pressure losses, flow turning and static pressure rise for the entire incidence range. The design goal with low losses and especially a wide operating range could be confirmed, as well as a mild stall behavior. Boundary layer development, particularly near stall condition, is discussed using surface flow visualization and the results of boundary layer calculations. An additional experimental study, using liquid crystal coating, provides necessary information on suction surface boundary-layer transition at high Reynolds numbers. Finally, results of Navier-Stokes simulations are presented which enlighten the total pressure loss development and flow turning behavior especially at high incidence in relation to the results of the design tool.

scholarly journals A New Approach to Designing the S-Shaped Annular Duct for Industrial Centrifugal Compressor

2014 ◽  
Vol 2014 ◽  
pp. 1-10 ◽  
Author(s):  
Ivan Yurko ◽  
German Bondarenko
Keyword(s):  
Centrifugal Compressor ◽  
Guide Vane ◽  
Geometric Parameters ◽  
Inlet Guide Vane ◽  
Annular Duct ◽  
Ansys Cfx ◽  
Wide Range ◽  
Variable Inlet Guide Vane ◽  
Full Factorial

The authors propose an analytical method for designing the inlet annular duct for an industrial centrifugal compressor using high-order Bezier curves. Using the design of experiments (DOE) theory, the three-level full factorial design was developed for determination of influence of the dimensionless geometric parameters on the output criteria. Numerical research was carried out for determination of pressure loss coefficients and velocity swirl angles using the software system ANSYS CFX. Optimal values of the slope for a wide range of geometric parameters, allowing minimizing losses in the duct, have been found. The study has used modern computational fluid dynamics techniques to develop a generalized technique for future development of efficient variable inlet guide vane systems. Recommendations for design of the s-shaped annular duct for industrial centrifugal compressor have been given.

Aerodynamic Optimization of a Two-Part Variable Inlet Guide Vane in a Highly Loaded Low Pressure Compressor

2018 ◽  
Author(s):  
Stefan Hemmert-Pottmann ◽  
William Gouézou ◽  
Eberhard Nicke
Keyword(s):  
Design Optimization ◽  
Total Pressure ◽  
Guide Vane ◽  
Low Pressure ◽  
Operating Conditions ◽  
Inlet Guide Vane ◽  
Wide Range ◽  
Variable Inlet Guide Vane ◽  
Operating Points ◽  
Pressure Compressor

Continuous reduction of fuel consumption for a wide range of operating conditions leads to a high efficiency demand for all engine parts of modern jet engines and especially the compressor. To meet these requirements a two-part Variable Inlet Guide Vane (VIGV), composed of a fixed strut and a variable flap, can be used. Besides the aerodynamic aspects, the VIGV strut is a substantial part for the structural integrity of the compressor. The aerodynamic design optimization of such a VIGV, located upstream of the first rotor of a 2.5 stage low pressure compressor, under the conditions of three different operating points is presented in this paper. In a previous study the shape of the axial gap between strut and flap was optimized without changing the envelope of both parts [1]. The new design tool SplitBlade, developed at the DLR, enables the creation of an axial gap and has been integrated in the design process of the in-house optimization tool AutoOpti. The target of the optimization was to decrease the total pressure loss coefficients for all three operating points. The design optimization presented in this paper is more complex by allowing the VIGV blade geometry to change. The basic dimensions of the VIGV such as the axial chord and the maximum profile thickness are still frozen. In total, 88 parameters are free to change in the optimization process. Additionally to the main target of loss reduction, the circumferential outflow angles are restricted to maintain the deflection of the blade and therewith the required rotor inflow conditions to ensure the operability of the entire compressor in the whole working range. The final result is a two-part VIGV with an axial gap, which is optimized in terms of total pressure losses in three operating points. Compared to a reference geometry without an axial gap, the losses are almost equal at nominal speed, and about one to two percentage points higher in the two part speed operating points.

Aerodynamic Investigations of an Advanced VIGV Design of Adjustable Geometry for Very High Flow Turning

2015 ◽  
Author(s):  
David Händel ◽  
Reinhard Niehuis ◽  
Jan Klausmann
Keyword(s):  
Pressure Loss ◽  
Total Pressure ◽  
High Speed ◽  
Guide Vane ◽  
Operating Conditions ◽  
Total Pressure Loss ◽  
Inlet Guide Vane ◽  
Basic Design ◽  
Low Loss ◽  
Symmetric Profile

On the basis of experimental results the new design of a Variable Inlet Guide Vane (VIGV), as can be used for the control and regulation in multishaft compressors, is presented. Main goal of this investigation is a significant increase of the operating range and a reduction of the total pressure loss compared to a currently used basic design. For both designs 2D-cascades were build for detailed measurements in the High-Speed Cascade Wind Tunnel at the Institute of Jet Propulsion at the Universität der Bundeswehr München. The basic design exhibits a symmetric profile with only one segment. In contrast to that the new VIGV design consists of two symmetric vane segments which are arranged pivotable to each other. This provides the advantage of a symmetric profile for a fully opened VIGV associated with a low-loss level. For guidance of the flow, both vane segments can be rotated. Hence, the turning of the flow is split onto two segments. This avoids a huge flow separation on the suction side for high turning angles (Δβ > 30°) which is linked with a strong and abrupt loss increase. Due to the design, the new VIGV exhibits a gap between the two vane segments. Results with opened and sealed gap are presented and discussed. Using a sealing between the segments, a reduction of the profile loss could be detected for all investigated operating conditions. Even without a sealing in the gap, the “low-loss working range” is significantly increased. In addition, it is depicted that the presented results are valid for varying inflow velocities. This broadens the usability of the outcomes. Concluding, it is shown that all aims are achieved. Using the new VIGV design with sealing the low-loss working range can almost be doubled (Δβ > 55°) and the total pressure loss decreases in every working condition compared to the basic design.

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