Heat transfer and fluid flow in a plate heat exchanger. Part II: Assessment of laminar and two-equation turbulent models

This paper presents a comparison of experimental data and numerical predictions for the hydrodynamic and thermal fields in a two-channel plate heat exchanger. The temperature distributions on the first and the last of the three plates, the friction factor and the Nusselt number for each channel as well as the outlet temperatures of the two streams are compared. The laminar model has satisfactorily been validated for Reynolds numbers less than 400. For the turbulent flow regime, several two-equation models were tested and the Realizable κ–ɛ model with non-equilibrium wall functions has been found to give the closest results to the experimental data. The flow distribution in cross-sections of the channels was studied numerically. Streams of higher velocities on the channels’ sides, where two narrow vertical smooth passages are located, were observed.