6.3.7. STEP 7 : Compute the fluxes in the y-direction

The heart of the problem is in the subroutine INTERCELL (INTERsection of CELLs). First, in 1D it is crucial to understand what fluxes are computed. Answer the followong:

• Are all the fluxes computed on every cells? Is the riemann solver used on every cell ?
• What is the property of finite volume fomulation used ?
• Why, in 1D, does apear only a special tretament for the WEST boundary condition in this subroutine?
• Is the solution provided unique?

Draw a sketch of the existing solution representing where the fluxes are computed. Extend it in 2D.

Then you can go to the programmation for the 2D!!

To check if all is OK, keep on solving the 1D shock tube problem in the x-direction, with NY=1.

Warning

Do not forget to extend the loops over the faces from 1 to 4 (instead of 2 to 4 by step 2)…