Effect of vortex shedding in unsteady aerodynamic forces for a low Reynolds number stationary wing at low angle of attack

2016 ◽  
Vol 64 ◽  
pp. 138-148 ◽  
Author(s):  
A. Villegas ◽  
F.J. Diez
Keyword(s):  
Reynolds Number ◽  
Vortex Shedding ◽  
Low Reynolds Number ◽  
Angle Of Attack ◽  
Aerodynamic Forces ◽  
Unsteady Aerodynamic ◽  
Low Reynolds

The Effects of Flexible Deformation on an Oscillating Airfoil at Low Reynolds Number

2011 ◽  
Vol 117-119 ◽  
pp. 610-614
Author(s):  
Jiang Hao Wu ◽  
Chao Zhou ◽  
Yan Lai Zhang
Keyword(s):  
Reynolds Number ◽  
Phase Difference ◽  
Low Reynolds Number ◽  
Aerodynamic Performance ◽  
Aerodynamic Forces ◽  
Unsteady Aerodynamic ◽  
Deformation Parameters ◽  
Low Reynolds ◽  
Time Courses ◽  
Flexible Deformation

The objective of investigation is to use numerical simulation obtain the effect of three different flexible deformation parameters (the maximum deforming amplitude, the phase difference between the plunging motion and the deformation motion and location of the maximum deforming) on unsteady aerodynamic performance of an airfoil with plunging and pitching motion. It is shown the effect of flexible deformation at low Reynolds number is obvious. The effect of the maximum deforming amplitude and the phase difference on aerodynamic forces is quite significant while the time courses of CL and CT don’t almost change with location of the maximum deforming. Different deforming amplitude and the phase difference may be advantageous or disadvantageous for averaged aerodynamic forces. Larger phase difference can produce more thrust and make the forward flight faster. Compared with the rigid airfoil, the appreciate combination of deformation parameters is beneficial in MAV design.

scholarly journals FLAPPING WING DEVICES FOR MARS EXPLORATION

2011 ◽  
Author(s):  
Asier Ania ◽  
Dominique Poirel ◽  
Marie-Josée Potvin ◽  
Steeve Montminy
Keyword(s):  
Reynolds Number ◽  
Insect Flight ◽  
Low Reynolds Number ◽  
Flapping Wing ◽  
Low Density ◽  
Mars Exploration ◽  
Unsteady Aerodynamic ◽  
Aerial Vehicle ◽  
Low Reynolds

The use of an aerial vehicle would greatly enhance the domain of exploration on Mars. The main constraint in such a design would be the extreme Martian environment. The low-density atmosphere suggests the use of a low Reynolds number flight regime modeled after flapping wing insect flight. This flapping wing flight employs several unsteady aerodynamic mechanisms; delayed stall, wake capture, and rotational mechanisms. Two prototypes, a flapping wing and a rotary-flapping wing hybrid, have been built and will be tested in order to quantify the 'overall lift' generated and allow us to evaluate the efficacy of flapping wing flight on Mars.

Vortex Shedding Analysis in the Wake of a Flat Plate at Low Incidence and Low Reynolds Number

2021 ◽  
Author(s):  
Bastav Borah ◽  
Anand Verma ◽  
Vinayak Kulkarni ◽  
Ujjwal K. Saha
Keyword(s):  
Reynolds Number ◽  
Velocity Field ◽  
Flat Plate ◽  
Vortex Shedding ◽  
Low Reynolds Number ◽  
General Tendency ◽  
Flat Plates ◽  
Trailing Edge ◽  
Low Reynolds ◽  
Low Incidence

Abstract Vortex shedding phenomenon leads to a number of different features such as flow induced vibrations, fluid mixing, heat transfer and noise generation. With respect to aerodynamic application, the intensity of vortex shedding and the size of vortices play an essential role in the generation of lift and drag forces on an airfoil. The flat plates are known to have a better lift-to-drag ratio than conventional airfoils at low Reynolds number (Re). A better understanding of the shedding behavior will help aerodynamicists to implement flat plates at low Re specific applications such as fixed-wing micro air vehicle (MAV). In the present study, the shedding of vortices in the wake of a flat plate at low incidence has been studied experimentally in a low-speed subsonic wind tunnel at a Re of 5 × 104. The velocity field in the wake of the plate is measured using a hot wire anemometer. These measurements are taken at specific points in the wake across the flow direction and above the suction side of the flat plate. The velocity field is found to oscillate with one dominant frequency of fluctuation. The Strouhal number (St), calculated from this frequency, is computed for different angles of attack (AoA). The shedding frequency of vortices from the trailing edge of the flat plate has a general tendency to increase with AoA. In this paper, the generation and subsequent shedding of leading edge and trailing edge vortices in the wake of a flat plate are discussed.

scholarly journals Determine Aerodynamic Characteristics for FX63-137 Aerofoil by Using Subsonic Wind Tunnel

2014 ◽  
Vol 695 ◽  
pp. 651-654 ◽  
Author(s):  
Magedi Moh M. Saad ◽  
Norzelawati Asmuin
Keyword(s):  
Reynolds Number ◽  
Aluminum Alloy ◽  
Wind Tunnel ◽  
Low Reynolds Number ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Cnc Machine ◽  
Subsonic Wind Tunnel ◽  
Low Reynolds

This paper is primarily concentrated with determining aerodynamic characteristics and choosing the best angle of attack at a maximum lift and low drag for the FX 63-137 aerofoil at a low Reynolds number and a speed of 20m/s and 30m/s, by using subsonic wind tunnel through manufacturing the aerofoil by aluminum alloy using a CNC machine. The proposed methodology is divided into several stages. Firstly, manufacturing the aerofoil using an aluminum alloy. Secondly, the testing process is carried out using subsonic wind tunnel. Thirdly, the results are displayed and compared with results produced from related works, in order to find out the best angle of attack at a maximum lift.

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