On Mon, Nov 19, 2018 at 11:10 PM Brandon Denton <[email protected]> wrote:
> Good evening. > > No. I'm trying to solve compressible navier-stokes in conservative form. > > dU/dt + (Ai + Bi)dU/dxi + d/dxi(cij*dU/dxj) = 0 > > After taking the inner product of the weighting functions (W) and the > residual, integrated over the domain and apply the divergence theorem, I > get the integrand for the domain as > > W*(Ai + Bi)dU/dxi + dW/dxi*(cij*dU/dxj) > > With the surface integrand as > > -W*(cij*dU/dxj) > > To do the domain integral via quadrature, I would need dW/dxi at the > quadrature point. I know I can get JxW and calculate all components of Ai, > Bi, cij and dU/dxi using context.interior_value and > context.interior_gradient (after proper reorganization). > > I just can't seem to figure out dW/dxi. Since I still need the geometric > jacobian J, I was wondering if JxdW/dxi was available or some way I could > calculate it. > The "W" in your context is a test function while the W in "JxW" is the quadrature weight. The FE::get_phi() and FE::get_dphi() functions provide access to the test function values and shape derivatives, respectively. Have a look at the various examples and you should be able to figure out what's going on. -- John _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
