Numerical modelling and experimental validation of jet impingement technology for professional appliances

We propose a combined numerical/experimental investigation of the heating/cooling process taking place in modern jetimpingement (JI henceforth) professional appliances. In food processing, the JI is mainly employed in industrial continuous tunnel machines, though it is exploited also in some professional appliances operating in batch mode. We set up an experimental facility, representative of a typical commercial JI appliance for food processing, in terms of dimensions and operative conditions. Experiments are carried out to provide the spatial distribution of the heat transfer coefficient on the exposed surface of a thick metal slab, positioned at known distance from the nozzles, under cooling conditions. Velocity and temperature measurements are acquired and compared against the numerical results. Once validated, the proposed numerical model can provide detailed maps of the Nusselt number under different flow conditions. These, in turn, are used as input data for a computationally-efficient, numerical heat-conduction model, which can be envisaged as a potential design tool for heating/cooling professional appliances based on JI technology.