CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   Main CFD Forum (https://www.cfd-online.com/Forums/main/)
-   -   shear stress calculation on the surface of cylinder (https://www.cfd-online.com/Forums/main/86208-shear-stress-calculation-surface-cylinder.html)

 HaKu March 17, 2011 00:51

shear stress calculation on the surface of cylinder

hey

I have written a code to solve compressible flow over 2 D cylinder....

i want to know how can i calculate the shear stress on the surface....

i need it to ultimately find the drag of the cylinder....

any help will be helpful.....i have the pressure values, and u and v values r there ....

step by step instruction will help me in order to obtain the shear stress on the surface of the cylinder....

thanksss

 lalupp March 26, 2011 08:05

Total drag mainly consists of pressure drag + viscous drag(shear)
finding pressure drag (Fx) is very simple equal to sum of (pressure x area) for all wall faces along X direction.
To find shear stress you need rate of deformation tensor. Multiplying this with viscosity will give you stress tensor ( laminar assumption) . That you can convert into forces along x dircetion multyplying by correcsoding area.