Abstract
Turbulent impinging jets at three different jet nozzle forms were numerically analyzed using the SIMPLE algorithm and k-epsilon turbulent model to investigate the flow field and heat transfer characteristics. The food placed upon a moving conveyor belt cooled by series of impinging jets under a specific condition. Three semi-confined domains with different jet nozzles were established, thereby with slot, rectangular, and funnel-shaped nozzles, respectively. Based on computational fluid dynamic (CFD) calculations, distributions of the temperature and wind velocity at four critical cross-sections of domains were compared. The results reveal that the freezing rate of foods mainly relates to temperature and wind velocity. For three semi-confined domains, the impinging jet with slot nozzles produces higher exit wind velocity, lower center temperature, and a better mass flow uniformity than others, which could better improve the heat transfer performance, and could increase the freezing rate of foods.
Flow and Heat Transfer Characteristics of Cone Orifice Free and Impinging Jets (Effects of Cone Angle)
