CFD investigation of a unit cell inside a Plate Heat Exchanger

Abstract: A numerical investigation of the unit cell approach has been done to reduce the computational cost for CFD (Computational Fluid Dynamics) of plate heat exchangers (PHE) at Alfa Laval. The reduced cost would enable LES (Large Eddy Simulation) to be done which would give a more detailed and accurate insight into the flow and heat transfer processes of the PHE. The unit cell which is repeatable in all directions is created by cutting out a small domain consisting of four contact points between the upper and lower plate of a full plate channel. Simulations of the unit cell have been done using LES in the software Ansys Fluent and compared with simulations of a whole plate done by Karlsson et al. [1]. The method of going from CAD (Computer Aided Design) to a CFD simulation of the unit cell has been developed and evaluated resulting in a recommendation regarding the method. It was found that the unit cell was able to capture the large-scale physics while the smaller scales were overpredicted. Taking this into consideration the method seems promising but still has room for improvement.