Analysis of the air infiltration through the doorway of a refrigerated room using different approaches

This paper presents the study of the air movement through the doorway of a refrigerated room, using both numerical and experimental approaches. Firstly, a comparison is made between the experimentally observed infiltration rates and the predictions by seven empirical models. For different test conditions of the specific laboratory configuration under analysis (a refrigerated room at laboratory scale), the infiltration rate was measured using the tracer gas technique. A three-dimensional numerical model was developed to simulate the heat and mass transfer phenomena, using a commercial CFD code (ANSYS-CFX (R)). For the simulations, turbulence effects were taken into account using the k-omega SST turbulence model. CFD results showed a good agreement with experimental data, confirming that the numerical model is appropriate to evaluate this physical phenomenon. The experimental and numerical results showed that the neutral flow level is located above the doorway mid-height and that the maximum airflow velocity occurs near the doorposts. Results also evidenced that, although most of the empirical models tend to overestimate the infiltration rate, some of them present a quite good prediction ability. Measurements in a real scale refrigerated room confirmed the trend obtained in the laboratory installation.