1 NUMERICAL AND EXPERIMENTAL INVESTIGATIONS ON THE USE OF MIST FLOW PROCESS IN REFRIGERATED DISPLAY CABINETS

Open Refrigerated Display Cabinets (RDCs) play an essential role in food preservation as they are considered as one of the weakest links of the cold chain. This study concerns the use of mist flow whereby fine water droplets are injected into the air curtain to improve the performance of RDCs. The deposition and evaporation of droplets on the surface of products partially compensate the radiative heat gained by the product by removing from it the amount of latent heat of the evaporated droplets. This mist-cooling process leads to a decrease in the surface temperature of the products. In this paper, the velocity characteristics of the air curtain and the temperature levels on the product surface were investigated numerically and experimentally. The experiments were carried out on an actual display cabinet. Numerical modelling was performed using Fluent Computational Fluid Dynamics (CFD) software. Numerical predictions have been carried out using the Renormalization Group (RNG) k-ε turbulence model, and the boundary layer of the air curtain, was fully solved using the enhanced wall treatment procedure. Good agreement was seen between numerical and experimental data in single-phase flow. In two-phase flow, an Euler-Lagrange approach was adopted to predict the transport of droplets by the air curtain and their spatial distribution on the produc