Influence of inlet shear on the 3-D flow past a square cylinder at moderate Reynolds number

2009 ◽  
Vol 25 (5) ◽  
pp. 889-896 ◽  
Author(s):  
A. Lankadasu ◽  
S. Vengadesan
Keyword(s):  
Reynolds Number ◽  
Square Cylinder ◽  
Flow Past ◽  
Moderate Reynolds Number

Suppression of fluid force on flow past a square cylinder with a detached flat plate at low Reynolds number for various spacing ratios

2014 ◽  
Vol 28 (12) ◽  
pp. 4969-4978 ◽  
Author(s):  
Shams Ul Islam ◽  
Hamid Rahman ◽  
Waqas Sarwar Abbasi ◽  
Uzma Noreen ◽  
Aftab Khan
Keyword(s):  
Reynolds Number ◽  
Flat Plate ◽  
Low Reynolds Number ◽  
Square Cylinder ◽  
Fluid Force ◽  
Flow Past ◽  
Low Reynolds

Anisotropy-Invariant Mapping of Turbulence in a Flow Past an Unswept Airfoil at High Angle of Attack

2005 ◽  
Vol 128 (3) ◽  
pp. 559-567 ◽  
Author(s):  
N. Jovičić ◽  
M. Breuer ◽  
J. Jovanović
Keyword(s):  
Reynolds Number ◽  
Large Scale ◽  
Separation Bubble ◽  
Flow Behavior ◽  
Angle Of Attack ◽  
High Angle ◽  
High Angle Of Attack ◽  
Fine Grid ◽  
Flow Past ◽  
Moderate Reynolds Number

Turbulence investigations of the flow past an unswept wing at a high angle of attack are reported. Detailed predictions were carried out using large-eddy simulations (LES) with very fine grids in the vicinity of the wall in order to resolve the near-wall structures. Since only a well-resolved LES ensures reliable results and hence allows a detailed analysis of turbulence, the Reynolds number investigated was restricted to Rec=105 based on the chord length c. Admittedly, under real flight conditions Rec is considerably higher (about (35-40)∙106). However, in combination with the inclination angle of attack α=18 deg this Rec value guarantees a practically relevant flow behavior, i.e., the flow exhibits a trailing-edge separation including some interesting flow phenomena such as a thin separation bubble, transition, separation of the turbulent boundary layer, and large-scale vortical structures in the wake. Due to the fine grid resolution applied, the aforementioned flow features are predicted in detail. Thus, reliable results are obtained which form the basis for advanced turbulence analysis. In order to provide a deeper insight into the nature of turbulence, the flow was analyzed using the invariant theory of turbulence by Lumley and Newman (J. Fluid Mech., 82, 161–178, 1977). Therefore, the anisotropy of various portions of the flow was extracted and displayed in the invariant map. This allowed us to examine the state of turbulence in distinct regions and provided an improved illustration of what happens in the turbulent flow. Thus, turbulence itself and the way in which it develops were extensively investigated, leading to an improved understanding of the physical mechanisms involved, not restricted to a standard test case such as channel flow but for a realistic, practically relevant flow problem at a moderate Reynolds number.

scholarly journals A Study on Large Eddy Simulation of High Reynolds Number Flow Past A Square Cylinder

2019 ◽  
pp. 332-339
Author(s):  
Samiran Sandilya ◽  
Amit Kumar
Keyword(s):  
Reynolds Number ◽  
Large Eddy Simulation ◽  
Square Cylinder ◽  
Practical Applications ◽  
Reynolds Number Flow ◽  
Eddy Simulation ◽  
Flow Past ◽  
Large Eddy ◽  
Flow Features ◽  
High Reynolds

Flow past a square cylinder has been studied extensively for over a century, because of its interesting flow features and practical applications. This problem is of fundamental interest as well as important in many engineering applications. The characteristics of flow around a square cylinder placed at symmetric condition are governed by the Reynolds number (Re). In the present study two dimensional simulations of flow past a square cylinder have been carried out for a Reynolds number of 21400. It has been studied numerically using the large-eddy simulation technique. The modeling of the problem is done by ANSYS 17.1 preprocessing software.

scholarly journals Vortex Trapping Cavity on Airfoil: High-Order Penalized Vortex Method Numerical Simulation and Water Tunnel Experimental Investigation

Energies ◽  
2021 ◽  
Vol 14 (24) ◽  
pp. 8402
Author(s):  
Dominik Błoński ◽  
Katarzyna Strzelecka ◽  
Henryk Kudela
Keyword(s):  
Reynolds Number ◽  
Flow Analysis ◽  
Vortex Method ◽  
High Order ◽  
Stream Velocity ◽  
Water Tunnel ◽  
High Order Schemes ◽  
Flow Past ◽  
Moderate Reynolds Number ◽  
Poisson Stream

This paper presents a two-dimensional implementation of the high-order penalized vortex in cell method applied to solve the flow past an airfoil with a vortex trapping cavity operating under moderate Reynolds number. The purpose of this article is to investigate the fundamentals of the vortex trapping cavity. The first part of the paper treats with the numerical implementation of the method and high-order schemes incorporated into the algorithm. Poisson, stream-velocity, advection, and diffusion equations were solved. The derivation, finite difference formulation, Lagrangian particle remeshing procedure, and accuracy tests were shown. Flow past complex geometries was possible through the penalization method. A procedure description for preparing geometry data was included. The entire methodology was tested with flow past impulsively started cylinder for three Reynolds numbers: 550, 3000, 9500. Drag coefficient, streamlines, and vorticity contours were checked against results obtained by other authors. Afterwards, simulations and experimental results are presented for a standard airfoil and those equipped with a trapping vortex cavity. Airfoil with an optimized cavity shape was tested under three angles of attack: 3°, 6°, 9°. The Reynolds number is equal to Re = 2 × 104. Apart from performing flow analysis, drag and lift coefficients for different shapes were measured to assess the effect of vortex trapping cavity on aerodynamic performance. Flow patterns were compared against ultraviolet dye visualizations obtained from the water tunnel experiment.

Sign in / Sign up

Export Citation Format

Share Document