Publication

Abstract : Numerical modeling of growth of a single bubble in nucleate flow boiling is presented in this paper. The modeling is done using the open-source CFD software OpenFOAM. The bulk fluid velocities used in the current study are 0.076 m/s and 0.1 m/s. A flow domain is chosen such that the bulk fluid temperature is at its saturation and the walls are at a higher temperature than the bulk fluid temperature. OpenFOAM has inbuilt solvers for solving various problems. First of all, a base solver is selected which deals with two-phase flow problems. Continuity, momentum and energy equations are solved numerically and the interface is captured by volume-of-fluid (VOF) method. The interfacial forces such as drag and lift which act on the bubble are also included. Thus a new solver namely bubbleEvapTempFoam is created and compiled for the current investigation. Initially a bubble is set up with a given diameter using the setFieldsDict dictionary. The boundary conditions such as pressure, velocity of fluid, velocity of vapor, temperature and void fraction are provided in the 0 dictionary. These conditions are applied at the internal bulk fluid and the boundaries such as inlet, outlet and walls. Output at various instances are viewed by using the post processing utility paraView. Bubble diameter as a function of time are estimated from the void fraction contours and is plotted. Bubble growth for different initial bubble diameters are also studied. The results are compared with data from previous literatures