scholarly journals Experimental Investigation of Drag Reduction by Trailing Edge Tabs on a Square Based Bluff Body in Ground Effect

2015 ◽  
Author(s):  
Scott R Sawyer
Keyword(s):  
Experimental Investigation ◽  
Drag Reduction ◽  
Bluff Body ◽  
Ground Effect ◽  
Trailing Edge

Experimental Investigation of the Effect of Camber on the Aerodynamic Characteristics of Airfoils in Ground Effect

2003 ◽  
Author(s):  
M. R. Ahmed ◽  
G. M. Imran ◽  
S. D. Sharma
Keyword(s):  
Experimental Investigation ◽  
Angle Of Attack ◽  
Ground Effect ◽  
Chord Length ◽  
Wake Region ◽  
Trailing Edge ◽  
Mean Velocity ◽  
Large Defect ◽  
Freestream Velocity ◽  
Ground Clearance

In the present paper, results from an experimental investigation of aerodynamic ground effect on two airfoils are presented. The flow characteristics over a symmetrical airfoil (NACA 0015) and a cambered airfoil (NACA 4415) were studied in a low speed wind tunnel. Experiments were carried out by varying the angle of attack from 0° to 10° and ground clearance from zero to one chord length. Pressure distribution on the surface of the airfoil was obtained with the help of pressure tappings. Mean velocity distributions were obtained over the surface of the airfoil. Profiles of mean velocity and turbulence intensity were obtained in the wake region at 0.5 and 1.0 chord length downstream of the trailing edge. It is found that pressure increases on the lower surface as the ground is approached. The flow accelerates over the airfoil, and a considerably higher mean velocity is observed near the suction peak location. For the symmetrical airfoil, the mean velocity over the surface was found to increase by nearly 30%, while for the cambered airfoil, an increase of nearly 60% was recorded for an angle of attack of 7.5°. The flow was found to separate almost near the trailing edge for angles of attack upto 10°, resulting in a thinner wake region and lower turbulence intensities for the symmetrical airfoil; while for the cambered airfoil, an early separation for an angle of attack of 10° was observed. Measurements in the wake region showed a defect in mean velocity profile at the corresponding values of ground clearance. For lower angles of attack, turbulence levels were higher in the wake region for the symmetrical airfoil, while for an angle of attack of 10°, very large defect in velocity was observed for the cambered airfoil model and the minimum velocity reduced to 20% of the freestream velocity.

Experimental investigation of the ground effect on a wing without/with trailing edge flap

2020 ◽  
Vol 52 (4) ◽  
pp. 045504
Author(s):  
Khalida Sekhoune Özden ◽  
İlyas Karasu ◽  
Mustafa Serdar Genç
Keyword(s):  
Experimental Investigation ◽  
Ground Effect ◽  
Trailing Edge ◽  
Trailing Edge Flap

Drag Reduction of a Simple Bluff Body by Changing the Rear End and Use the Ground Effect

2009 ◽  
Author(s):  
Jesper Marklund ◽  
Lennart Lofdahl
Keyword(s):  
Flow Field ◽  
Drag Reduction ◽  
Bluff Body ◽  
Ground Effect ◽  
Model Testing ◽  
Scale Model ◽  
Bluff Bodies ◽  
Ground Vehicle ◽  
University Of Technology ◽  
Force Reduction

The flow field around bluff bodies constitutes a classic area within fluid dynamics and has been the topic for much research through the years. However, in the use for road vehicles with the effect of the ground, the behavior is changed very much from more classical aviation usage. In this paper we are investigating the drag force reduction on a vehicle like simplified model with rear open diffuser when stationary ground simulation is considered. The objective with this work was to study the rear end of a bluff body and optimize it for drag with ground vehicle like boundaries. Here the testing contains two common body variants, square back, boat tailed/fastback in generic forms. Scale model testing combined with simulations is used to explain behavior and flow field. The model testing is performed in the L2 scale model wind tunnel at Chalmers University of Technology in Gothenburg, Sweden. Simulations are done with the commercial CFD code Fluent. A diffuser on a car is normally used to create down force but here it is tested to see if the energy in the flow can be used to optimize reduction of drag. One part of the study is to show the potential in optimizing the rear end underbody for drag, by varying the diffuser angle. The results show a potential in drag reduction by using a diffuser and varying effect depending on other rear end geometries.

Drag reduction in flow over a two-dimensional bluff body with a blunt trailing edge using a new passive device

2006 ◽  
Vol 563 ◽  
pp. 389 ◽  
Author(s):  
HYUNGMIN PARK ◽  
DONGKON LEE ◽  
WOO-PYUNG JEON ◽  
SEONGHYEON HAHN ◽  
JEONGLAE KIM ◽  
...  
Keyword(s):  
Drag Reduction ◽  
Bluff Body ◽  
Two Dimensional ◽  
Trailing Edge ◽  
Passive Device ◽  
Blunt Trailing Edge

Experimental investigation of a simulated compressor airfoil trailing-edge flowfield

AIAA Journal ◽  
1985 ◽  
Vol 23 (5) ◽  
pp. 768-775 ◽  
Author(s):  
Robert W. Paterson ◽  
Harris D. Weingold
Keyword(s):  
Experimental Investigation ◽  
Trailing Edge

scholarly journals Experimental Investigation of the Ground Transportation Systems (GTS) Project for Heavy Vehicle Drag Reduction

1996 ◽  
Author(s):  
Robert H. Croll ◽  
Walter T. Gutierrez ◽  
Basil Hassan ◽  
Jose E. Suazo ◽  
Anthony J. Riggins
Keyword(s):  
Experimental Investigation ◽  
Drag Reduction ◽  
Transportation Systems ◽  
Heavy Vehicle
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