An efficient ψ ‐ v scheme for two‐dimensional laminar flow past bluff bodies on compact nonuniform grids

2020 ◽  
Vol 92 (12) ◽  
pp. 1723-1752
Author(s):  
Pankaj Kumar ◽  
Jiten C. Kalita
Volume 4 ◽  
2004 ◽  
Author(s):  
Takao Fujita ◽  
Keizo Watanabe

Laminar drag reduction is achieved by using a hydrophobic surface. In this method, fluid slip is applied at the hydrophobic surface. An initial experiment to clarify for a laminar skin friction reduction was conducted using ducts with a highly water-repellent surface. The surface has a fractal-type structure with many fine grooves. Fluid slip at a hydrophobic surface has been analyzed by applying a new wet boundary condition. In this simulation, an internal flow is assumed to be a two-dimensional laminar flow in a rectangular duct and an external flow is assumed to be a two-dimensional laminar flow past a circular cylinder. The VOF technique has been used as the method for tracking gas-liquid interfaces, and the CSF model has been used as the method for modeling surface tension effects. The wet boundary condition for the hydrophobic property on the surface has been determined from the volume ratio in contact with water near the surface. The model with a stable gas-liquid interface and the experimental results of flow past a circular cylinder at Re = 250 without growing the Karman vortex street are made, and these results show that laminar drag reduction occurring due to fluid slip can be explained in this model.


2006 ◽  
Vol 295 (1-2) ◽  
pp. 407-427 ◽  
Author(s):  
Y.S.K. Liow ◽  
B.T. Tan ◽  
M.C. Thompson ◽  
K. Hourigan

2020 ◽  
Vol 905 ◽  
Author(s):  
J. Sierra ◽  
D. Fabre ◽  
V. Citro ◽  
F. Giannetti

Abstract


1976 ◽  
Vol 77 (1) ◽  
pp. 129-152 ◽  
Author(s):  
Sheldon Weinbaum ◽  
Michael S. Kolansky ◽  
Michael J. Gluckman ◽  
Robert Pfeffer

A new approximate theory is proposed for treating the flow past smoothly contoured two-dimensional bluff bodies in the intermediate Reynolds number rangeO(1) <Re< 0(102), where the displacement effect of the thick viscous layer near the surface of the body is large and a steady laminar wake is present. The theory is based on a new pressure hypothesis which enables one to take account of the displacement interaction and centrifugal effects in thick viscous layers using conventional first-order boundary-layer equations. The basic question asked is how the wall pressure gradient in ordinary boundary -layer theory must be modified if the pressure gradient along the displacement surface using the Prandtl pressure hypothesis is to be equal to the pressure gradient along this surface using a higher-order approximation to the Navier-Stokes equation in which centrifugal forces are considered. The inclusion of the normal pressure field with displacement interaction is shown to be equivalent to stretching the streamwise body co-ordinate in first-order boundary-layer theory such that the streamwise pressure gradient as a function of distance along the original and displacement body surfaces are equal.While the new theory is of a non-rigorous nature, it yields results for the location of separation and detailed surface pressure and vorticity distribution which are in remarkably good agreement with the large body of available numerical Navier-Stokes solutions. A novel feature of the new boundary-value problem is the development of a simple but accurate approximate method for determining the inviscid flow past an arbitrary two-dimensional displacement body with its wake.


1992 ◽  
Vol 114 (3) ◽  
pp. 439-442 ◽  
Author(s):  
A. S. Ramamurthy ◽  
R. Balachandar

A model is developed to predict the choking cavitation number for sharp edged bluff bodies subject to wall interference effects. The fact that the forebody pressure distribution under cavitating conditions essentially resembles the values obtained in noncavitating flows is made use of in the development of the model. The model is verified using experimental results from present and previous studies for a specific case of choking flow past a two-dimensional prismatic body.


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