The development of acoustic generators and their application as a boundary layer transition control device

1991 ◽  
Vol 11-11 (2-3) ◽  
pp. 93-104 ◽  
Author(s):  
H. U. Meier ◽  
M.-D. Zhou
Keyword(s):  
Boundary Layer ◽  
Control Device ◽  
Boundary Layer Transition ◽  
Layer Transition ◽  
Transition Control

An Experimental Investigation of Passive Control Device: Blade Wake Interaction on a Ultra High Lift Turbine Profile

2008 ◽  
Author(s):  
Daniele Simoni ◽  
Marina Ubaldi ◽  
Pietro Zunino ◽  
Francesco Bertini ◽  
Ennio Spano
Keyword(s):  
Boundary Layer ◽  
Experimental Investigation ◽  
Reynolds Number ◽  
Passive Control ◽  
Control Device ◽  
Boundary Layer Transition ◽  
Critical Conditions ◽  
Ensemble Averaging ◽  
Layer Transition ◽  
High Lift

The transition of the boundary layer subjected to unsteady wake-passing in a linear cascade of ultra high lift profiles has been investigated at the Avio Aerodynamics Laboratory. The blade profiles are representative of the turbine nozzle mid section of a long range aeroengine. Measurements were performed at the cruise Reynolds number. A surface hot-film array was adopted to survey the boundary layer nature and the periodic variations related to the passing wakes. A phase-locked ensemble averaging technique was employed in order to separate the random fluctuations from the periodic ones. Results have been represented in space-time plots in order to provide an overall view of the time-dependent phenomena in terms of the quasi wall shear stress statistical moments, that are important parameters for the analysis of the boundary layer transition and separation. Passive control devices may be adopted to suppress boundary layer laminar separation at critical conditions (low Reynolds numbers, ultra high lift profiles). In the present experimental investigation a wavy step device has been mounted on the suction side of the blade. The effects of this boundary layer control device on the transition process and profile losses have been investigated at cruise Reynolds number, with and without incoming wakes.

scholarly journals Transition Effect on the Flow Dynamics in a Compressor Blade Passage

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Ryszard Szwaba ◽  
Piotr Kaczynski ◽  
Janusz Telega
Keyword(s):  
Boundary Layer ◽  
Shock Wave ◽  
Flow Control ◽  
Flow Dynamics ◽  
Boundary Layer Transition ◽  
The Other ◽  
Control Methods ◽  
Layer Transition ◽  
Blade Passage ◽  
Transition Control

An experimental investigation was carried out to study the effect of the boundary layer transition on the flow dynamics in the blade passage of a compressor cascade. A model of a turbine compressor passage was designed and assembled in a transonic wind tunnel for this purpose. Two different flow control methods were used in the experiment to induce the transition upstream of the shock wave, one concerning the microstep application and the other using distributed roughness strips. Two locations of spanwise microsteps for the transition trigger were chosen, one at the leading edge and the other closer to the shock wave position. The distributed roughness in the form of standard sandpaper strips with different heights was applied in three various locations on the blade upstream of the shock. The main objective of investigations is to present the influence of the laminar and turbulent shock wave-boundary layer interaction on the flow dynamics in a compressor fan passage, and the specific objective is to show how the parameters of particular transition control methods affect the flow dynamics in the investigated channel. The major challenge for this research was to minimize the disturbance caused by the microstep or roughness to the laminar boundary layer, while still ensuring a successful transition. Very interesting results were obtained in the flow control application for the boundary layer transition control, demonstrating a positive effect on the flow unsteadiness in changing the nature of the interaction.

scholarly journals Mechanisms of Roughness-Induced Boundary-Layer Transition Control by Shielding

AIAA Journal ◽  
2020 ◽  
Vol 58 (7) ◽  
pp. 2951-2963
Author(s):  
Saikishan Suryanarayanan ◽  
David B. Goldstein ◽  
Alexandre R. Berger ◽  
Edward B. White ◽  
Garry L. Brown
Keyword(s):  
Boundary Layer ◽  
Boundary Layer Transition ◽  
Layer Transition ◽  
Transition Control
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