Fixed-grid Numerical Modeling of Frost Formation

A finite volume method to solve the frost growth using dynamic meshes

“…Despite the efforts to simulate the frost-free air coupled problem, there is still a lack of consensus in which empirical correlations capture better the frost formation. Furthermore, solutions with CFD approaches use static grids [7,8,13,14,15,16], which lead to a non-accurate tracking of the interface.…”

Fixed grid numerical modelling of frost growth and densification

“…The study shows good agreement of the accumulated frost among the three meshes. Furthermore, the mesh comparison carried out in [23] also showed that the rate of ice deposition is almost unchanged when changing from meshes with cell sizes of {1, 1}mm to {0.1, 0.1}mm. As a consequence, and recalling that the main purpose of the present study is to introduce and emphasize a new methodology capable to simulate the frost growth, the present 2D-study shows the results acquired with a uniform structured mesh of 220 x 10 cells, with ∆x = 0.5mm and ∆y = 0.4mm.…”

“…Moreover, due to the fact that the largest eigenvalue among the convective and diffusive terms of the full set of equations (Eqs. 2 -4) corresponds to the diffusive term of the energy equation, it is hereby treated implicitly, resulting in an increase of the time step, and a reduction of the computational costs, compared to the ones reached in [23]. As a consequence, the limitation of the explicit time step is then given by the eigenvalue of the convective term of the momentum equation.…”

“…Furthermore, a uniform inlet velocity boundary condition is used. This boundary condition is preferred over the parabolic profile formerly used in [23], as the increased experimental thickness values close to the inlet suggest the existence of enhanced gradients in that region.…”

“…The present paper sets a single-domain approach method, as an improvement to [23]. The new model, which consists of a single set of equations, accounts for the formation and sublimation of frost by means of a momentum equation for flow through the frost layer (based on the previous works of Galione et al [24,25], in the line of the works of Hsu and Cheng [26] and Voller and Prakash [27]), as well as a water vapour transport and energy equations that determine the state of a cell, and thus, the phase change.…”