Unsteady Boundary Layer Development Due to Wake Passing Effects on a Highly Loaded Linear Compressor Cascade

The effects of wake passing on boundary layer development on a highly loaded linear compressor cascade were investigated in detail on the suction side of a compressor blade. The experiments were performed in the High Speed Cascade Wind Tunnel of the Institut fuer Strahlantriebe at Mach and Reynolds numbers representative for real turbomachinery conditions. The experimental data were acquired using different measurement techniques, such as fast-response Kulite sensors, hot-film array and hot-wire measurements. The incoming wakes clearly influence the unsteady boundary layer development. Early forced transition in the boundary layer is followed in time by calmed regions. Large pressure fluctuations detectable in the ensemble averaged Kulite data reveal the existence of coherent structures in the boundary layer. Distinct velocity variations inside the boundary layer are amplified when approaching the blade surface. The time-mean momentum thickness values are reduced compared to the steady ones and therefore clarify the potential for a loss reduction due to wake passing effects.© 2004 ASME

[1]  Gregory J. Walker,et al.  Periodic transition on an axial compressor stator : Incidence and clocking effects : Part I : Experimental data , 1999 .

[2]  Stefan Brunner,et al.  The Use of Hot-Wire Anemometry to Investigate Unsteady Wake-Induced Boundary-Layer Development on a High-Lift LP Turbine Cascade , 2000 .

[3]  R. Mailach,et al.  Aerodynamic Blade Row Interactions in an Axial Compressor-Part I: Unsteady Boundary Layer Development (2003-GT-38765) , 2003 .

[4]  H. Pfeil,et al.  Investigation of the Laminar-Turbulent Transition of Boundary Layers Disturbed by Wakes , 1982 .

[5]  H. Pfeil,et al.  Transition Procedure of Instationary Boundary Layers , 1979 .

[6]  U. Orth.  Unsteady Boundary-Layer Transition in Flow Periodically Disturbed by Wakes , 1993 .

[7]  Meinhard T. Schobeiri,et al.  Modeling Unsteady Boundary Layer Transition on a Curved Plate Under Periodic Unsteady Flow Conditions: Aerodynamic and Heat Transfer Investigations , 1997 .

[8]  Howard P. Hodson,et al.  Boundary Layer Development in Axial Compressors and Turbines: Part 4 of 4—Computations and Analyses , 1997 .

[9]  Marius Swoboda,et al.  The Influence of Multimode Transition Initiated by Periodic Wakes on the Profile Loss of a Linear Compressor Cascade , 2000 .

[10]  B. Lakshminarayana,et al.  A Method of Measuring Three-Dimensional Rotating Wakes Behind Turbomachinery Rotors , 1974 .

[11]  Horst Pfeil,et al.  Turbulenzverhältnisse hinter rotierenden Zylindergittern , 1976 .

[12]  Howard P. Hodson,et al.  Boundary Layer Development in Axial Compressors and Turbines: Part 2 of 4 — Compressors , 1995 .

[13]  Howard P. Hodson,et al.  Boundary Layer Development in Axial Compressors and Turbines: Part 3 of 4— LP Turbines , 1997 .

[14]  Howard P. Hodson,et al.  An Investigation of Boundary Layer Development in a Multistage LP Turbine , 1994 .

[15]  R. E. Mayle,et al.  The 1991 IGTI Scholar Lecture: The Role of Laminar-Turbulent Transition in Gas Turbine Engines , 1991 .

[16]  Meinhard T. Schobeiri,et al.  Effect of unsteady wake passing frequency on boundary layer transition, experimental investigation and wavelet analysis , 1995 .