engleski

Ice Melting Druven by Natural Convection in the Rectangular Cavity Filled with Water

The influence of natural convection during melting of a long ice block in rectengular cavity with isothermal vertical walls is analyzed numerically. The ice block in the middle of the cavity and the initial volume of ice is 1/8 of the cavity volume. The unsteady two-dimensional melting of ice is governed by the continuity, momentum and energy equations and by the following assumptions:the liquid phase is incompressibleand the Boussinesq approximation is met, the flow is laminarand viscous dissipation is neclected. The finite volume method is adopted and computations are carried out on a non-fixed grid. The governing equations are discretised using the exponential differencing scheme for spatial derivates and the fully implicit scheme for the time integration: The SIMPLER algorithm is used for the pressure -velocity coupling. In the cases of the wall temperature higher than 8C, the melting process can be devided into three typical successive regims: an initial pure conduction regime, a transition regime and a convection dominated regime.In the case of hot wall temperature equal 8 C, two vortices are separated by nearly vertical 4 C isotherm and the average Nusselt number remains constant during the time interval corresponding to the first sub-regime of the convection dominated regime. In the case of hot wall temperature higher than 8 C, the ice melts faster frome above, and for the one lower than 8 C from below.

ice melting; moving boundary; isothermal walls; natural convection; rectengular cavity; numerical solution

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