|February 19, 2013, 17:19||
Problem obtaining right Cd
Join Date: Oct 2012
Posts: 3Rep Power: 5
Hi guys, quite new to openFoam.
I'v been running these 2 cases recently. A cylinder as well as a square cylinder.
I decided on using a value of Re of 100,000 so as to compare with a book.
Im using pisoFoam, k-e model and used initial values of k and e from the equations given here: http://en.wikipedia.org/wiki/Turbulence_kinetic_energy
Currently running on a single core (dont know who to run in parallel just yet)
Meshing for both are quite dense but i get values of Cd of 0.7 for cylinder (should 1.2) and Cd of 1.7 for sqaure cylinder (should be 2.1)
Could these inaccurate values be a meshing problem? I did increase the mesh and after almost a 6hr simulation, i still got roughly the same Cd for the square cylinder. so im not sure exactly what my next step is.
functionObjectLibs ("libforces.so"); //Lib to load
patches (cylinder); // change to your patch name
rhoInf 1.1614; //Reference density for fluid
CofR (0 0 0); //Origin for moment calculations
// rhoInf - reference density
// CofR - Centre of rotation
// dragDir - Direction of drag coefficient
// liftDir - Direction of lift coefficient
// pitchAxis - Pitching moment axis
// magUinf - free stream velocity magnitude
// lRef - reference length
// Aref - reference area
CofR (0 0 0);
liftDir (0 1 0);
dragDir (1 0 0);
pitchAxis (0 0 1);
lRef 1; //
Aref 0.1; //
Any help would be much appreciated!
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