Numerical Analysis of forced convection in plate and frame heat exchangers

A three-dimensional numerical investigation of flow field and heat transfer in sine-wave crossed ducts is presented. Numerical simulations are carried out using a finite element procedure based on an algorithm which shares many features with the SIMPLER finite-volume method, and utilizes equal order pressure-velocity interpolation functions. Since the flow, after a short entrance regime, reaches the fully developed condition, the computational domain can be reduced to a single periodic element and periodic boundary conditions are assumed at the entrance, the exit and the sides. The thermal performance and the frictional pressure losses of the crossed-corrugated plates are investigated for different Reynolds number, from steady up to transitional regimes. The evolution from steady to unsteady flow structure is detected and the influence of the unsteadiness on heat transfer and on pressure drop is analysed. Simulations are performed for both air (Pr = 0.7) and water (Pr = 7) as the flow medium and the dependence of Nusselt number on Prandtl number is investigated