Numerical analysis of the bubble detachment diameter in nucleate boiling

Abstract

E-mail: isabellamas@udc.esAbstract. The present paper presents a tri-dimensional CFD (Computational Fluid Dynamics) model to investigate the fluid flow around bubbles attached to heated walls. Transient solutions of the governing field equations in a domain containing the bubbles and the surrounding liquid have been obtained. The nucleation, growing and detachment processes have been analyzed. Concerning the software, the open source OpenFOAM has been used. Special attention has been given to the bubble detachment diameter. Two mechanisms have been considered as physically related to the detachment: surface tension and buoyancy. As expected, it has been verified that the bubble detachment diameter depends on the contact angle, operating pressure and properties of the fluid. Several fluids have been considered (water, R134a, ammonia and R123), as well as several operating pressures (between 0.1 and 10 bar) and contact angles (between 10 and 80º). It has been concluded that the detachment diameter depends strongly on the contact angle and fluid properties and slightly on the pressure. A correlation for the bubble detachment diameter has been developed based on the obtained numerical results. Data from this expression compare reasonably well with those from other correlations from the literature.

A numerical evaluation of the contribution of different heat transfer mechanisms in nucleate boiling

“…As this is an open software, it allows a complete flexibility in the programming of the governing equations. Regarding the validation of the numerical model, it has been satisfactory compared with experimental results obtained on previous works, Lamas et al [15,16].…”

Nucleate Pool Boiling on A Plain Surface

“…The results were given in pixels and then converted to millimeters. flow around bubbles by analyzing nucleation, growing and detachment processes [10]. In the study, open source software OpenFOAM was used.…”