From: li pan <li76pan@ya...>  20070423 10:36:07

Hallo, I'm calculating a kind of NavierStokes equation. After one "solve", I get the velocity vector. Then I'll evaluate displacement. Here, I have to transform the velocity vector from Euler coordinates to Lagrange coordinates, because of convective derivative: vel: velocity at time t u: displacement at time t I : identity matrix vel(t) = d_u/d_t + grad(u,t)*vel(t). I need to do something like: d_u/d_t = (I+grad(u,t))vel(t) My question is, how to do it effectively? I don't want to go over all elements, nodes again, to calculate the deformation gradient. Do you have good idea ? pan __________________________________________________ Do You Yahoo!? Tired of spam? Yahoo! Mail has the best spam protection around http://mail.yahoo.com 