A Study of Asymmetric Vortex Shedding Behind Missiles at High Angle of Attack Using Dynamic Solution Adaptive Meshes.

1995 ◽  
Author(s):  
Paul D. Orkwis
Keyword(s):  
Vortex Shedding ◽  
Angle Of Attack ◽  
High Angle ◽  
Adaptive Meshes ◽  
High Angle Of Attack ◽  
Asymmetric Vortex ◽  
Dynamic Solution

NUMERICAL STUDIES OF ASYMMETRIC VORTEX FLOWS AROUND A SLENDER BODY AT HIGH ANGLE OF ATTACK

2005 ◽  
Vol 19 (28n29) ◽  
pp. 1463-1466
Author(s):  
TONGQING GUO ◽  
ZHILIANG LU
Keyword(s):  
Stokes Equations ◽  
Angle Of Attack ◽  
Navier Stokes ◽  
Finite Volume Scheme ◽  
Vortex Flows ◽  
High Angle ◽  
High Angle Of Attack ◽  
Asymmetric Vortex ◽  
Vortex Pattern ◽  
Asymmetric Shape

The asymmetric vortex flows about slender bodies at high angle of attack are investigated numerically. 3D O-O type multi-block structured grids are adopted for the computation, and a series of small spatial disturbances are imposed on the leeward body surface near the tip to trigger the asymmetry. The unsteady Navier-Stokes equations are solved using a dual-time method based on the cell-centered finite-volume scheme. Comparisons between numerical results and experimental data demonstrate that the asymmetric vortex pattern observed in the experiment is successfully simulated. In a certain small perturbation level, the magnitude of the side-force is independent of the size of the spatial perturbation, but its direction is dependent on the direction of the spatial perturbation, i.e. a counterclockwise or clockwise circumferential angle from the leeward meridian. When perturbation is removed, the flow field returns to its original asymmetric shape after a period of oscillation.

scholarly journals Fluid structure interactions of a pitching wing at high angle of attack

2021 ◽  
Vol 1 (1) ◽  
Author(s):  
Gwenael Acher ◽  
Patrick Braud ◽  
Ludovic Chatellier ◽  
Lionel Thomas ◽  
Laurent David
Keyword(s):  
Vortex Shedding ◽  
Angle Of Attack ◽  
Fluid Structure Interactions ◽  
High Angle ◽  
High Angle Of Attack ◽  
Fluid Structure

This paper deals with the study of the flow around a pitching wing at high angle of attack. Different pitching amplitudes and frequencies are studied using DIC and LPT measurements. The Fluid Structure Interactions are shown and exhibit that the vortex shedding could be reduced by actuating the wing at specific frequencies.

scholarly journals Leading Edge Blowing to Mimic and Enhance the Serration Effects for Aerofoil

2021 ◽  
Vol 11 (6) ◽  
pp. 2593
Author(s):  
Yasir Al-Okbi ◽  
Tze Pei Chong ◽  
Oksana Stalnov
Keyword(s):  
Boundary Layer ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Boundary Layer Separation ◽  
Shear Instability ◽  
Vortical Flow ◽  
High Angle ◽  
High Angle Of Attack ◽  
Layer Separation ◽  
Aerodynamic Performances

Leading edge serration is now a well-established and effective passive control device for the reduction of turbulence–leading edge interaction noise, and for the suppression of boundary layer separation at high angle of attack. It is envisaged that leading edge blowing could produce the same mechanisms as those produced by a serrated leading edge to enhance the aeroacoustics and aerodynamic performances of aerofoil. Aeroacoustically, injection of mass airflow from the leading edge (against the incoming turbulent flow) can be an effective mechanism to decrease the turbulence intensity, and/or alter the stagnation point. According to classical theory on the aerofoil leading edge noise, there is a potential for the leading edge blowing to reduce the level of turbulence–leading edge interaction noise radiation. Aerodynamically, after the mixing between the injected air and the incoming flow, a shear instability is likely to be triggered owing to the different flow directions. The resulting vortical flow will then propagate along the main flow direction across the aerofoil surface. These vortical flows generated indirectly owing to the leading edge blowing could also be effective to mitigate boundary layer separation at high angle of attack. The objectives of this paper are to validate these hypotheses, and combine the serration and blowing together on the leading edge to harvest further improvement on the aeroacoustics and aerodynamic performances. Results presented in this paper strongly indicate that leading edge blowing, which is an active flow control method, can indeed mimic and even enhance the bio-inspired leading edge serration effectively.

Sign in / Sign up

Export Citation Format

Share Document