4. METHOD OF SOLUTION
The mathematical model consists of two parts -
the flow distribution and the temperature distribution. Navier- Stokes equations are applied to the flow problem. The temperature distribution differential equations are integrated using a Crank- Nickolson technique. The resulting algebraic equations are solved with a Gauss-Seidel iterative procedure.
A rectangular grid is superimposed on the reactor to define the mesh spaces. There are 142 mesh spaces in the active core, 146 in the side reflector, and 52 in the gas annulus between the core barrel and PCRV liner. Axially, there are 20 mesh spaces for a total of 6800 representing the entire system.