Technique for calculation of a three-dimensional coolant flow in rod boundles

Application of methods for plotting Navier-Stokes equation finite-difference approximations in rate/pressure variables in rectangular grids to motion equation approximation in trigonal grids inserted into trigonal fuel element cluster geometry allowed one to construct a family of conservative difference circuits to calculate three-dimensional flows both in fuel element cluster and in space without fuel elements. Equation solution algorithm, called PORTER, is resistant under Kurant numbers exceeding one. Application of partial runs in the cluster axial direction makes it possible to considerably increase the limiting Kurant number under which resistance is retained. Algorithm approbation taking blockage flowing-around problem solution as an example has shown, that the calculated picture of coolant flow in the trace qualitatively agrees with the actual picture