Implementation of CLEAR algorithm on collocated grid system and application examples

Implementation of the CLEAR algorithm on a collocated grid system is conducted. Detailed discussion of the previous momentum interoperation method (MIM) is given to analyze the condition to get a unique converged solution that is independent of relaxation factor for steady flow. Six numerical examples on nonstaggered grids of forced-convective fluid flow and natural convection are provided to compare the convergence performance between CLEAR and SIMPLER. The domain extension method, widely used on staggered grids to deal with mildly irregular domains, is further refined to meet the requirement of collocated grids. It is shown that on a collocated grid the CLEAR algorithm can also greatly enhance the convergence rate, based on iteration number and CPU time consumed, compared with the SIMPLER algorithm with similar robustness.