Numerical Prediction of Natural Convection and Freezing of a Porous Humid Food inside a Freezer

In this paper heat transfer during the freezing of a porous humid plate shaped food in a freezing chamber is simulated. The 2D unsteady Navier-Stokes and energy equations for an incompressible Newtonian fluid are solved. The semi-implicit method of SIMPLE algorithm is used to solve the governing equations. The specific heat capacity method has been used to model the freezing process. After solving velocity and temperature fields, the effects of different factors, such as Rayleigh number, aspect ratio and initial water content of food on the freezing time have been examined. Present results indicate that the higher initial water content of food increases the freezing time, but the Rayleigh number enhancement decreases the freezing time. The numerical method has been compared with published numerical results for a block in a cavity and good agreement has been achieved. Also, validation of the proposed freezing model has been done by comparing with existing experimental results.

کلیدواژه ها:

food freezing ، numerical study ، naturalconvection