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<\/a>This project grew out of the course MEAM646 Computational Mechanics instructed by the CFD expert Dr. Howard Hu. The course mainly teaches basic concepts including matrix solving,\u00a0FVM<\/b>(finite volume method),\u00a0SIMPLER<\/strong>\u00a0algorithm,\u00a0staggered grid<\/strong>\u00a0implementation and other techniques that enable accurate and efficient computing of 2D transport equations.\u00a0A\u00a0C<\/strong>-based program was provided for us to test and to build projects on. I decided to extend the capability of the program to simulate\u00a0double-diffusive turbulence<\/strong>\u00a0and for the final project, I planned to use\u00a0level-set<\/strong>\u00a0method to simulate\u00a0multi-phase flow<\/strong>.<\/p>\nDouble-diffusive turbulence is rooted from\u00a0buoyancy-driven instability<\/strong>\u00a0where temperature and salinity contribute adversely to the density with one having the\u00a0stabilizing effect and another destabilizing the system. \u00a0The fact that the magnitude of the two scalars\u2019 influences on the density is different and that their diffusivities are different makes the parametric space multi-dimensional.<\/p>\n This instability is especially dominant\u00a0in\u00a0oceanography<\/strong>. The surface of the ocean is usually warmer due to the radiation absorption and saltier due to the evaporation compared to the bottom of the ocean. Once the the fluid surface is perturbed, suppose a fluid parcel from the upper layer have a chance to dive down, the fluid parcel quickly give away\u00a0heat to the environment(the diffusivity of temperature is higher) and become even denser. As a result, the instability develops and the interplay between the flow and the scalars give rise to rich\u00a0behaviors.<\/p>\n