Compressor Blade Boundary Layers: Part 1 — Test Facility and Measurements With No Incident Wakes

1989 ◽  
Author(s):  
Y. Dong ◽  
N. A. Cumpsty
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Compressor Blade ◽  
Test Facility ◽  
Compressor Blades ◽  
Present Part

The boundary layers on compressor blades are sensitive to the conditions at which transition occurs and transition can be affected by the convection of wakes from upstream blade rows. This paper and its companion, Part 2 by the same authors, describes an experiment to study the effect of the moving wakes on the boundary layer of a compressor blade. This paper describes the background and facility devised to introduce wakes together with results obtained on the blades in tests without the wakes present. Part II describes the measurements made with the wakes present and presents conclusions for the whole project. Further details of all aspects of the work can be found in Dong (1988).

Compressor Blade Boundary Layers: Part 1—Test Facility and Measurements With No Incident Wakes

1990 ◽  
Vol 112 (2) ◽  
pp. 222-230 ◽  
Author(s):  
Y. Dong ◽  
N. A. Cumpsty
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Compressor Blade ◽  
Test Facility ◽  
Compressor Blades ◽  
Present Part

The boundary layers on compressor blades are sensitive to the conditions at which transition occurs and transition can be affected by the convection of wakes from upstream blade rows. This paper and its companion, Part 2 by the same authors, describes an experiment to study the effect of the moving wakes on the boundary layer of a compressor blade. This paper describes the background and facility devised to introduce wakes together with results obtained on the blades in tests without the wakes present. Part 2 describes the measurements made with the wakes present and presents conclusions for the whole project. Further details of all aspects of the work can be found in Dong (1988).

scholarly journals Boundary Layers on Rough Compressor Blades

1972 ◽  
Author(s):  
K. Bammert ◽  
R. Milsch
Keyword(s):  
Boundary Layer ◽  
Friction Coefficient ◽  
Boundary Layers ◽  
Axial Flow ◽  
Experimental Results ◽  
Experimental Investigations ◽  
Compressor Blades ◽  
Turbulent Transition ◽  
Good Reproduction ◽  
Compressor Efficiency

Blades of axial flow compressors are often roughened by corrosion or erosion. There is only scant information about the influence of this roughening on the boundary layers of the blades and thereby on the compressor efficiency. To obtain detailed information for calculating the efficiency drop due to the roughness, experimental investigations with an enlarged cascade have been executed. The results enabled to develop new formulas for a modified friction coefficient in the laminar region and for the laminar-turbulent transition and the separation points of the boundary layer. Thus, together with the Truckenbrodt theory, it was possible, to get a good reproduction of the experimental results.

The Measurement of Boundary Layers on a Compressor Blade in Cascade: Part 3—Pressure Surface Boundary Layers and the Near Wake

1988 ◽  
Vol 110 (1) ◽  
pp. 146-152 ◽  
Author(s):  
S. Deutsch ◽  
W. C. Zierke
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Velocity Profiles ◽  
Compressor Blade ◽  
Laser Doppler Velocimeter ◽  
Surface Boundary ◽  
Local Pressure ◽  
Near Wake ◽  
Mean Velocity ◽  
Pressure Surface

Using the facility described in Part 1 [23], 11 detailed velocity and turbulence intensity profiles are obtained on the pressure surface of a double circular arc compressor blade in cascade. Two profiles are obtained in the near wake. Laminar boundary layer profiles, which agree well with profiles calculated from Falkner–Skan theory at the local pressure gradient, persist through 57.2 percent chord. The measurements indicate that the onset of transition occurs near 60 percent chord—a value in good agreement with the sublimation flow visualization studies (see Part 1). The lack of a logarithmic region in the data measured at the last chord position (97.9 percent chord) indicates that transition is not complete. The thin laminar boundary layers near the leading edge lead to some measurement problems, which are characterized by large turbulence intensities, in using the laser-Doppler velocimeter (LDV). Close examination of this problem shows that a combination of velocity-gradient broadening and a vibration of the LDV measurement volume causes an elevation of the measured turbulence levels. Fortunately only small errors in mean velocity are introduced. Because of the detached boundary layer on the suction surface, both of the near-wake velocity profiles exhibit regions of backflow. As expected, these near-wake velocity profiles do not exhibit similarity when tested against criteria derived for the far wake.

The Effect of Wake Induced Structures on Compressor Boundary-Layers

2006 ◽  
Author(s):  
Andrew P. S. Wheeler ◽  
Robert J. Miller ◽  
Howard P. Hodson
Keyword(s):  
Boundary Layer ◽  
Pressure Transducer ◽  
Leading Edge ◽  
Compressor Blade ◽  
Blade Surface ◽  
Cfd Simulations ◽  
Compressor Blades ◽  
System A ◽  
Dynamic Head ◽  
Pressure Perturbations

The interaction of a convected wake with a compressor blade boundary-layer was investigated. Measurements within a single-stage compressor were made using an endoscopic PIV system, a surface mounted pressure transducer, hotfilms and hotwire traverses, along with CFD simulations. The wake/leading-edge interaction was shown to lead to the formation of a thickened laminar boundary-layer, within which turbulent spots formed close to the leading-edge. The thickened boundary-layer became turbulent and propagated down the blade surface, giving rise to pressure perturbations of 7% of the inlet dynamic head in magnitude. The results indicate that wake/leading-edge interactions have a crucial role to play in the performance of compressor blades in the presence of wakes.

scholarly journals Compressor Blade Boundary Layers in the Presence of Wakes

1995 ◽  
Author(s):  
N. A. Cumpsty ◽  
Y. Dong ◽  
Y. S. Li
Keyword(s):  
Laminar Flow ◽  
Boundary Layers ◽  
Compressor Blade ◽  
Pressure Gradients ◽  
Compressor Blades ◽  
Different Types

Transition on compressor blades is strongly affected by the wakes from upstream blade rows and by the strong adverse pressure gradients which tend to make the laminar flow to separate. This paper outlines the processes involved and illustrates them with measurements on two different types of blade. Of particular importance is the calmed region which follows any turbulent patch created by a wake; the calmed region resists transition from other disturbances and is able to overcome strong adverse pressure gradients without separation.

Compressor Blade Boundary Layers: Part 2 — Measurements With Incident Wakes

1989 ◽  
Author(s):  
Y. Dong ◽  
N. A. Cumpsty
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Transition Process ◽  
Compressor Blade ◽  
Momentum Thickness ◽  
Trailing Edge ◽  
Boundary Layer Development ◽  
Blade Row ◽  
Layer Development

This paper follows directly from Part I** by the same authors and describes measurements of the boundary layer on a supercritical-type compressor blade with wakes from a simulated moving upstream blade row convected through the passage. (The blades and the test facilities togehter with the background are described in Part I.) The results obtained with the wakes are compared to those with none for both low and high levels of inlet turbulence. The transition process and boundary layer development is very different in each case though the overall momentum thickness at the trailing edge is fairly similar. None of the models for transition is satisfactory when this is initiated by moving wakes.

The Effect of Wake Induced Structures on Compressor Boundary-Layers

2006 ◽  
Vol 129 (4) ◽  
pp. 705-712 ◽  
Author(s):  
Andrew P. S. Wheeler ◽  
Robert J. Miller ◽  
Howard P. Hodson
Keyword(s):  
Boundary Layer ◽  
Pressure Transducer ◽  
Leading Edge ◽  
Compressor Blade ◽  
Blade Surface ◽  
Cfd Simulations ◽  
Compressor Blades ◽  
System A ◽  
Dynamic Head ◽  
Pressure Perturbations

The interaction of a convected wake with a compressor blade boundary layer was investigated. Measurements within a single-stage compressor were made using an endoscopic PIV system, a surface mounted pressure transducer, hotfilms and hotwire traverses, along with CFD simulations. The wake/leading-edge interaction was shown to lead to the formation of a thickened laminar boundary-layer, within which turbulent spots formed close to the leading edge. The thickened boundary-layer became turbulent and propagated down the blade surface, giving rise to pressure perturbations of 7% of the inlet dynamic head in magnitude. The results indicate that wake/leading-edge interactions have a crucial role to play in the performance of compressor blades in the presence of wakes.

Compressor Blade Boundary Layers: Part 2—Measurements With Incident Wakes

1990 ◽  
Vol 112 (2) ◽  
pp. 231-240 ◽  
Author(s):  
Y. Dong ◽  
N. A. Cumpsty
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Transition Process ◽  
Compressor Blade ◽  
Momentum Thickness ◽  
Trailing Edge ◽  
Boundary Layer Development ◽  
Blade Row ◽  
Layer Development

This paper follows directly from Part 1 by the same authors and describes measurements of the boundary layer on a supercritical-type compressor blade with wakes from a simulated moving upstream blade row convected through the passage. (The blades and the test facilities together with the background are described in Part 1). The results obtained with the wakes are compared to those with none for both low and high levels of inlet turbulence. The transition process and boundary layer development are very different in each case, though the overall momentum thickness at the trailing edge is fairly similar. None of the models for transition is satisfactory when this is initiated by moving wakes.

The Departure from Equilibrium of Turbulent Boundary Layers

1968 ◽  
Vol 19 (1) ◽  
pp. 1-19 ◽  
Author(s):  
H. McDonald
Keyword(s):  
Boundary Layer ◽  
Shear Stress ◽  
Kinetic Energy ◽  
Stress Distribution ◽  
Boundary Layers ◽  
Turbulent Boundary Layers ◽  
Two Dimensional ◽  
Pressure Distributions ◽  
Momentum Integral ◽  
State Examination

SummaryRecently two authors, Nash and Goldberg, have suggested, intuitively, that the rate at which the shear stress distribution in an incompressible, two-dimensional, turbulent boundary layer would return to its equilibrium value is directly proportional to the extent of the departure from the equilibrium state. Examination of the behaviour of the integral properties of the boundary layer supports this hypothesis. In the present paper a relationship similar to the suggestion of Nash and Goldberg is derived from the local balance of the kinetic energy of the turbulence. Coupling this simple derived relationship to the boundary layer momentum and moment-of-momentum integral equations results in quite accurate predictions of the behaviour of non-equilibrium turbulent boundary layers in arbitrary adverse (given) pressure distributions.

Laminar boundary layers behind detonation waves

1983 ◽  
Vol 387 (1793) ◽  
pp. 331-349 ◽  
Keyword(s):  
Heat Transfer ◽  
Boundary Layer ◽  
Boundary Layers ◽  
Flow Analysis ◽  
Time Dependent ◽  
Detonation Waves ◽  
Planar Geometry ◽  
Laminar Boundary Layers ◽  
Spherical Detonation ◽  
Layer Flow

New solutions are presented for non-stationary boundary layers induced by planar, cylindrical and spherical Chapman-Jouguet (C-J) detonation waves. The numerical results show that the Prandtl number ( Pr ) has a very significant influence on the boundary-layer-flow structure. A comparison with available time-dependent heat-transfer measurements in a planar geometry in a 2H 2 + O 2 mixture shows much better agreement with the present analysis than has been obtained previously by others. This lends confidence to the new results on boundary layers induced by cylindrical and spherical detonation waves. Only the spherical-flow analysis is given here in detail for brevity.

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