Effect of riblets on the drag of a body of revolution with trailing-edge flow separation

1998 ◽  
Vol 33 (1) ◽  
pp. 135-139
Author(s):  
S. F. Konovalov ◽  
Yu. A. Lashkov ◽  
V. V. Mikhailov
Keyword(s):  
Flow Separation ◽  
Body Of Revolution ◽  
Trailing Edge ◽  
Edge Flow

Viscous tails in Hele-Shaw flow

1971 ◽  
Vol 46 (3) ◽  
pp. 569-576
Author(s):  
C. J. Wood
Keyword(s):  
Reynolds Number ◽  
Trailing Edge ◽  
Kutta Condition ◽  
Quantitative Discrepancy ◽  
Edge Flow ◽  
Hele Shaw Cell

An experiment has been performed, using pulsed dye injection on an aerofoil in a Hele-Shaw cell. The purpose was to observe the form of the trailing-edge flow when the Reynolds number was high enough to permit separation and the initiation of a Kutta condition. The experiment provides a successful confirmation of the existence of a ‘viscous tail’ as predicted by Buckmaster (1970) although there is an unexplained quantitative discrepancy.

Computation of the Trailing Edge Flow Downstream A Flat Plate with Finite Thickness

1989 ◽  
Vol 6 (1) ◽  
Author(s):  
E.I. Elbialy ◽  
A.M. Mobarak ◽  
M.A. Serag-Eldin
Keyword(s):  
Flat Plate ◽  
Finite Thickness ◽  
Trailing Edge ◽  
Edge Flow

Leading-edge Flow Separation

1970 ◽  
pp. 452-530 ◽  
Author(s):  
PAUL K. CHANG
Keyword(s):  
Flow Separation ◽  
Leading Edge ◽  
Edge Flow

CFD Investigation of the Flow of Trailing Edge Cooling Slots

2018 ◽  
Author(s):  
Y. Jiang ◽  
N. Gurram ◽  
E. Romero ◽  
P. T. Ireland ◽  
L. di Mare
Keyword(s):  
Mach Number ◽  
Kinetic Energy ◽  
Flow Separation ◽  
Film Cooling ◽  
High Speed ◽  
Turbine Blades ◽  
Cross Flow ◽  
Turbulent Energy ◽  
Trailing Edge ◽  
Flow Interactions

Slot film cooling is a popular choice for trailing edge cooling in high pressure (HP) turbine blades because it can provide more uniform film coverage compared to discrete film cooling holes. The slot geometry consists of a cut back in the blade pressure side connected through rectangular openings to the internal coolant feed passage. The numerical simulation of this kind of film cooling flows is challenging due to the presence of flow interactions like step flow separation, coolant-mainstream mixing and heat transfer. The geometry under consideration is a cutback surface at the trailing edge of a constant cross-section aerofoil. The cutback surface is divided into three sections separated by narrow lands. The experiments are conducted in a high speed cascade in Oxford Osney Thermo-Fluids Laboratory at Reynolds and Mach number distributions representative of engine conditions. The capability of CFD methods to capture these flow phenomena is investigated in this paper. The isentropic Mach number and film effectiveness are compared between CFD and pressure sensitive paint (PSP) data. Compared to steady k–ω SST method, Scale Adaptive Simulation (SAS) can agree better with the measurement. Furthermore, the profiles of kinetic energy, production and shear stress obtained by the steady and SAS methods are compared to identify the main source of inaccuracy in RANS simulations. The SAS method is better to capture the unsteady coolant-hot gas mixing and vortex shedding at the slot lip. The cross flow is found to affect the film significantly as it triggers flow separation near the lands and reduces the effectiveness. The film is non-symmetric with respect to the half-span plane and different flow features are present in each slot. The effect of mass flow ratio (MFR) on flow pattern and coolant distribution is also studied. The profiles of velocity, kinetic energy and production of turbulent energy are compared among the slots in detail. The MFR not only affects the magnitude but also changes the sign of production.

Development of a MEMS-Based Active Control System for Flow Separation in the Transonic Regime

2000 ◽  
Author(s):  
Steve Tung ◽  
Brant Maines ◽  
Fukang Jiang ◽  
Tom Tsao
Keyword(s):  
Shear Stress ◽  
Control System ◽  
Wind Tunnel ◽  
Flow Separation ◽  
Control Flow ◽  
Separation Control ◽  
Sensors And Actuators ◽  
Trailing Edge ◽  
Flow Separation Control ◽  
Mach Numbers

Abstract A MEMS-based active system is currently under development for flow separation control in the transonic regime. The system consists of micro shear stress sensors for flow sensing and micro balloon actuators for separation control. We have successfully completed the first phase of the program in which the micro sensors and actuators were fabricated and tested in a wind tunnel facility. In the test, the sensors and actuators were flush mounted on a 3D model, which is representative of the upper surface of a wing with a deflected trailing edge flap. The model was installed in the wind tunnel and tested at a series of Mach numbers between 0.2 and 0.6. For all Mach numbers, the sensor output indicates that flow separates over the trailing edge when the micro balloons are in the ‘down’ position. When the micro balloons are inflated, the shear stress level on the trailing edge increases substantially, indicating an improvement of the separation characteristics. This result demonstrates the feasibility of using MEMS sensors and actuators to control flow separation. It is the first step toward the development of a revolutionary closed loop flow control system applicable to existing and future aircraft to enhance aerodynamic performance.

Two-Velocities Hybrid RANS-LES of a Trailing Edge Flow

2009 ◽  
pp. 63-76 ◽  
Author(s):  
J. C. Uribe ◽  
N. Jarrin ◽  
R. Prosser ◽  
D. Laurence
Keyword(s):  
Trailing Edge ◽  
Edge Flow

DNS of a Compliant Trailing-Edge Flow

2013 ◽  
Author(s):  
Stefan C. Schlanderer ◽  
Richard D. Sandberg
Keyword(s):  
Trailing Edge ◽  
Edge Flow
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