Numerical simulation of hydrodynamic and thermal behaviours in a scraped surface heat exchanger operating in turbulent regime

Heat transfer in scraped-surface heat exchangers (SSHE) of processing turbu lent Rowing media has been numerically simulated using a two-equation k - e psilon turbulence model. The computational method, based on the control-vol ume technique, permits us to reveal the details of the thermal and hydrodyn amic patterns structured under various geometric and operator parameters. I n particular, attention is focused on the effect of the number of blades an d the rotational and axial Reynolds numbers on the temperature and velocity distributions. Back-mixing was shown by considering the temperature jump a t the inlet of the exchanger. Heat transfer coefficients were determined an d fitted with a power function using the dimensionless criteria Nu, Re, and Pr. Finally, a comparison with the penetration theory model and empirical earlier works has been carried out. (C) Elsevier, Paris.