A theoretical model for nucleate boiling of nanofluids considering the nanoparticle Brownian motion in liquid microlayer

Simulation of pool boiling of nanofluids by using Eulerian multiphase model

“…In this work, we examined this parameter to validate our model. The active nucleation sites density predicted by the present HFP model obtained from fitting the experimental data of [37] and used by [17,18]. It was inserted as UDF in the boiling parameters list of the present model, and the results show good agreement with experimental results of the literature as depicted in Fig.…”

“…The geometry was chosen as the experimental boiling chamber of [40] for the purpose of validation, and to ensure that it will not tolerate any edge effects on the vicinity of the heating wall to avoid the bubble capillary forces from the sides wall. As mentioned in Li et al [17,18] work, the time of transient initial stage was usually short and the nucleate pool boiling using nanofluids was mostly characterized by a quasi-steady state; hence, in this work the nucleate boiling was carried out at steady state…”

“…Due to near molecular mixing between the dilute concentration of nanoparticles and the base fluid, a nanofluid hydro dynamically behaves as it is pure base fluid, and therefore, single-phase modeling of nanofluid is reasonable to assume. On another hand, it was also believed that the vapor-phase is not dense enough to hold the nanoparticles within so, we assumed that the thermal properties of the vapor phase were not influenced by stable nanoparticles, as suggested by [16][17][18]26].…”

“…The heat and mass transfer during the nucleate pool boiling of pure liquids has been commonly predicted by using the Rensselaer Polytechnic Institute model [32,33], which is called the RPI model. In this classic boiling model, the total heat flux ̇q total from the surface is governed by three heat transfer mechanisms: the heat flux due to the natural convection that represented by the energy transfer from the formation bubbles to the bulk liquid ̇q conv , the heat flux due to the latent heat of vaporization ̇q evap , and the heat flux due to quenching ̇q quen , which is the process of the periodic averaged transient energy transfer related to liquid filling the wall vicinity after bubble separation [15][16][17][18].…”

“…It is widely known that the boiling of pure liquids complex and the presence of ultrafine particles increase this degree of complexity due to the interaction between exist phases, their interfaces and the heating surface [15]. Some new investigations show that many factors were affecting the pool boiling of nanofluids such as particle size, concentration, heating surface structure and bubbles dynamic; hence, studying such mechanisms theoretically need further investigations to build an accurate predictive model [16][17][18]. One of the most critical sub-phenomena involved in pool boiling of nanofluids is bubble dynamics during the nucleate regime; therefore, studying the bubble parameters with the presence of those ultrafine particles could result in an accurate predictive model for such mechanism.…”