Author(s): Ayurzana Badarch; Hosoyamada Tokuzo
Linked Author(s): Ayurzana Badarch
Keywords: No Keywords
Abstract: A phase change of water is an exceptional from other phase changing materials in environmental temperature on account of density inversion and thermal volume expansion. Conventional numerical modeling of phase change phenomena involve special care, i. e. additional set of equation, and treatment of moving boundary condition on the interface between two phases. However, those complexities can be eliminated when lattice Boltzmann method is employed on phase change simulation. We first solved a natural convection problem of water near its density inversion point in order to validate our developed LBM code. Validated numerical code have been extended to solve various types of freezing and melting problems in enclosure, which solved by conventional methods in the literature and results by LBM were in good agreement. Using precise density inversion in computation provides capability to determine accurate interface of melting/solidification in the fluid flow. The freezing and melting are opposite changes on same temperature point, but, processes take different time and show distinct flow behavior. Melting shows more active flow and unstable interface with the ice than freezing in the simulations. To demonstrate practical application of the code, we applied the method to ice melting due to flow over a weir with forced convection in turbulent flow. Our work might be first attempt to merge free surface simulation to phase change among LBM studies.
Year: 2016