Heat transfer and fluid flow in a refrigerator through door opening

In this study, natural convection within closed and open cavities are numerically investigated. For the closed cavity, side walls were kept at a constant temperature of Tcold and bottom wall was kept at a constant temperature of Thot while the top wall was assumed adiabatic. The conservation equations of mass, momentum and energy were being solved by using boussinesq approaches. Analyses were carried out for the numerical values of Rayleigh number between 103 and 105. For open cavity analysis, the wall which is facing to the open surface was kept constant Thot under assumption of the cavity's top and bottom surface areas are insulated. Calculations were done for the interval of 105 and 107 of Rayleigh number and dimensionless differences of the temperature, ԑ, values between 0.03 and 1.3 of the wall and liquid. The analyses made are compared with other literature studies¬ done. As a conclusion of the research, it was observed that the heat transfer coefficient and Nusselt number are increasing with respect to increase in Raleigh number. Moreover, hydrodynamic boundary layer and thermal boundary layer are observed to get thinner as per increase of Rayleigh number. As a conclusion for this study conducted, after detailed analysis and comparison with the literature, the work done is observed to produce similar results that are used as an indicative measure for reliability of the data and fridge is modeled in 2D and 3D. During 2D modeling, the investigation is grouped depending on the temperature that starts from 2, 4 and 6 Celsius and the number of the shelves 1, 2 or none. For the 3D model, 3 or 4 shelve situations, different shelves' height with same considerations including 2 and 4 Celsius temperature are investigated. Numerical analysis done shows that higher shelves tend to get warmer than the lower ones for the same duration exposed, while gain of energy tends to be lower inversely proportional to increased number of shelves and initial temperatures given. Moreover, reducing the height of the shelves above while increasing the height of the following shelves were observed to decreases the energy gain.