Simulations of the Boiling Process on a Porous Heater by Lattice Boltzmann Method

In order to research the process of boiling occurring on a porous surface, a model of multiple blocks was developed. The mathematical basis of these blocks is the lattice Boltzmann method in combination with heat transfer equation. The reported complex allows one to obtain the boiling curves for various wall superheats and to find the optimal parameters of a porous heater in terms of heat transfer enhancement. The porous heater structure is specified as a skeleton of square metal heaters located in the lower part of the computational domain. The calculations were performed for the following parameters of the porous heater structure: different number and size of the metal heaters, different distances between them in horizontal and vertical directions, regular and asymmetric packing of the heaters. Using the developed numerical model, parametric studies of the boiling process on porous heaters with different parameters of the porous skeleton were carried out and phase pictures of such a process were obtained. It was shown that the heat transfer coefficient on a porous heater is 3–7 times greater than that on a smooth heater, and depends on the number of heater elements, their size, and location. The results showed a significant advantage of the porous heaters with greater critical heat flux at higher wall superheats compared to that on the smooth surface.