Hello I am implementing your artificial viscosity approach http://arxiv.org/pdf/1102.3190v2.pdf in my own code https://code.google.com/p/cfdlab/source/browse/trunk/deal.ii/dg/1d_euler_le… It works for some problems (sod problem) but not for others (like Shu-Osher problem). Do you have any code available which I could try. Thanks praveen