A Comparison of the Rate Form of the Equation of State to the Jacobian Form

Abstract

Porsching's solution algorithm for the simulation of thermalhydraulic systems is com- pared to a new method based on the rate form of the equation of state. Both algorithms are developed and discussed. A direct comparison is made for a simple 2 node-1 link case to illustrate and numerically test the ideas presented. It is shown that the final algorithms of the two methods are identical and that the rate method is more intuitive, easy to implement and permits eigenvalue extraction. The modelling of the nonlinear damping term was found to be important when large time steps were taken.