Numerical investigation of nucleate pool boiling heat transfer

Abstract

Multi-dimensional numerical simulation of the atmospheric saturated pool boiling is performed. The applied modelling and numerical methods enable a full representation of the liquid and vapour two-phase mixture behaviour on the heated surface, with included prediction of the swell level and heated wall temperature field. In this way the integral behaviour of nucleate pool boiling is simulated. The micro conditions of bubble generation at the heated wall surface are modelled by the bubble nucleation site density, the liquid wetting contact angle and the bubble grow time. The bubble nucleation sites are randomly located within zones of equal size, where the number of zones equals the nucleation site density. The conjugate heat transfer from the heated wall to the liquid is taken into account in wetted heated wall areas around bubble nucleation sites. The boiling curve relation between the heat flux and the heated wall surface temperature in excess of the saturation temperature is predicted for the pool boiling conditions reported in the literature and a good agreement is achieved with experimentally measured data. The influence of the nucleation site density on the boiling curve characteristic is confirmed. In addition, the influence of the heat flux intensity on the spatial effects of vapour generation and two-phase flow are shown, such as the increase of the swell level position and the reduced wetting of the heated wall surface by the heat flux increase.

Boiling heat transfer modelling: A review and future prospectus

“…Finally, we outline the model for pool boiling on the horizontal heating surface developed in our research group. The model was established by Stosic and Stevanovic [31] and improved by Pezo and Stevanovic [32] and Stojanovic et al [33]. Different to the aforementioned approaches, which using empirical correlations for nucleation site density, n, determine the integral vapour generation per unit surface and unit time, in our approach the locations of individual nucleation sites are specified by use of the following algorithm.…”

Nucleate pool boiling heat transfer: Review of models and bubble dynamics parameters

“…Among the other efforts of near field model Pasamehmetoglu [16] described the phenomena by dry out of micro-layer (liquid layer of very small thickness below the growing bubble) and macrolayer. He et al [17], Stojanovic et al [18] and Pezo and Stevanović [19], numerically predicted the total boiling curve. They considered 3-D transient heat conduction through the heated wall to investigate the spatial variation of wall temperature.…”

“…Using the level set method as one of the widely-used interface tracking algorithms, the interface between phases is resolved and tracked. Stojanović et al [18] and Pezo and Stevanović [19] performed a multidimensional numerical simulation of the atmospheric saturated pool boiling, taking into account the micro conditions at the heated wall surface. The applied modelling and numerical methods enable a full representation of the liquid and vapor two-phase mixture behavior on the heated surface, with included prediction of the swell level and heated wall temperature field.…”

Bubble Dynamics and Nucleate Pool Boiling of Natural Convection

“…The numerical methodology and developed modelling disclosed that the combined application of the basic deterministic conservation laws for the continuous two-phase flow field, and the stochastic characteristics of the vapor generation at the heated wall might simulate complex pool boiling conditions [25,26]. The major roles of nanoparticles affected by nanofluid boiling heat transfer, including the bulk effect associated with suspended nanoparticles of the fluid and their thermal properties (thermal conductivity, viscosity, heat capacity and density), shall be well understood; the surface effect associated with deposit nanoparticles, which have modified the characteristics of heating surface (wettability, homogeneity, roughness and solid surface tension, etc.…”