JOURNAL OF ENGINEERING THERMOPHYSICS, cilt.28, ss.255-268, 2019 (SCI İndekslerine Giren Dergi)
In the present work, heat and mass transfer from different foods by impinging a slot hot air jet at low Reynolds numbers is numerically researched. Banana and apples are selected as foods due to their trading importance. Low Reynolds numbers are operated as Re = 100, 200 and 300. The diameters of the foods and initial jet height are taken as fixed in all examined situations and the impinging jet is laminar and two-dimensional. The shape of foods is assumed as a cylinder. The distance (D/H) between the cylinder and the slot is taken as another effective parameter of drying process and it is used with the three different distances (D/H = 0.22, 0.25, and 0.33) to search jet effectiveness on heat and mass transfer. A finite volume method is employed to solve governing equations of mass, momentum and energy by means of ANSYS Fluent 17.0 program. There is a good agreement with the numerical and experimental data available in the literature. The heat transfer increments and temperature variations for different Reynolds number values and for varying distance, D/H, and also temperature and mass distributions are researched for both inside the foods. It is obtained that heat and mass transfer enhanced with reducing the distance, D/H, between the jet and the cylinder. In addition, locally, the most effective jet drying is achieved close to the stagnation point on the front face of the foods.