Influence of near-wall modelling on boiling flow simulation

Heat transfer model for quenching by submerging

“…The rest of the closure relationships in order to get a well-posed problem were taken from [12]- [22]. In addition, the k − turbulence model for the liquid phase (taking into account the presence of disperse vapor) was used to describe the Reynolds stress tensor T T .…”

“…• by means of a heat transfer coefficient (h) depending on the global temperatures of the piece and cooling fluid, as it is presented in [2] - [5] or, • calculating the heat flux emitted by the piece (q w ) using the heat flux partition model, which is a function of global values of piece and fluid temperatures and fluid velocity, in a similar way as [17] - [22].…”

“…That specific phenomenon will be included in further studies. The heat transfered during boiling was described in a similar way than it is presented in [15]- [17], [19]- [22]. It is important to remark that due to the fact that our cooling fluid is oil, the functions presented for water were replaced for expressions based on physical properties of the fluid, rather than fitting constants [21].…”

Multi-Scale Modeling and Analysis of Convective Boiling: Towards the Prediction of CHF in Rod Bundles

“…(13). As a surface tension model, the Continuum Surface Force (CSF) model [43] is employed, for simplicity.…”

“…The present authors also believe that the occurrence of the thermal crisis must naturally result from a mechanistic description of the boiling processes. As boiling, as well as a number of other issues of interest to nuclear thermal-hydraulics, is controlled by the competition of numerous phenomena at various length and time scales, a multi-scale approach has been recognized as the only effective way to tackle the problem [10][11][12][13]. The strong industrial interest in better prediction methods for CHF is the driving force for the current project MSMA (Multi-Scale Modeling and Analysis of boiling), conducted jointly by the Paul Scherrer Institute (PSI) and the Swiss Nuclear Utilities (Swissnuclear).…”