A mathematical model is established to describe convective heat transfer in magnetic microencapsulated phase change material slurry (MMPCMS) flows in a circular tube under an external magnetic field. Influences of magnetic field strength, volume fraction of magnetic phase change materials (MMPCM), mass flow rate, and heat flux on convective heat transfer are analyzed. It shows that convective heat transfer of slurries is obviously enhanced by external magnetic field. Since distributions of MMPCM volume fraction and slurry temperature are changed clue to magnetic force on MMPCM.

A hybrid method is proposed to study microcosmic characteristics of nanofluid mulfiphase flows in a lattice Boltzmann approach. Multicomponent lattice Boltzmann model on fine mesh is used in regions where physical parameters, such as density and velocity change tempestuously, otherwise a single component one on coarse mesh is used. In order to keep continuity of physical information (physical parameters) in overlapping regions, principle of mass and momentum conservation is used. It shows that in the model microcosmic characteristics of nanofluid flow can be obtained. Computational efficiency is improved observably compared with a multicomponent method.

A lattice Bohzmann model is established to describe liquid-vapor phase transitions using a model proposed by Shan instead of the R-K model. Evaporation from a higher density phase to a lower density phase is simulated. The model improves calculation efficiency and obtains good results. The model is also used to simulate phase transitions in porous media with a pore scale to demonstrate feasibility of the model for complicate phase transition problems.