Engineering Physics Annotation << Back Estimation of the Numerical Diffusion of the Finite VolumeMethod in Condensation Modeling Using a Single-RateMultiphase Model of a Liquid With a Free Surface Kozelkov A.S., Puzan А.Yu. The article presents the results of a study of the numerical diffusion of the fi nite volume method in modeling condensation using a single-speed multiphase model of the liquid, taking into account the free surface. Studies are carried out on the basis of the problem of condensation of a single vapor bubble, for which both experimental data on the dynamics of changes in the size of the bubble and calculated data are available. For modeling, the Simple method is used, supplemented by the VOF model, implemented on the basis of fi nite-volume sampling for unstructured design grids. The Tanasawa model is considered as a condensation model, in which the evaporated or condensed mass linearly depends on the difference between the local temperature and the saturation temperature up to a certain empirical coeffi cient. As a result of the numerical solution of the problem of condensation of a single bubble, the maximum value of the Courant number was determined for various sampling schemes of the volume fraction transfer equation and types of calculated meshes, which is necessary for correct calculation of the shape and diameter of the condensed bubble. Keywords: fl uid dynamics, Navier-Stokes equations, condensation, VOF, free surface, mass transfer, steam. DOI: 10.25791/infizik.11.2024.1439 Pp. 41-54.