Огляд чисельних методів для моделювання сепарації потоку за температурою у закручених течіях рідини

The main objective of this paper is to present a generalized review of the methods used for the numerical analysis of the total temperature flow separation process in Ranque-Hilsch vortex tubes using computational fluid dynamics (CFD). The main attention is paid to the studies supported by experimental data and evaluated by the authors as being in good agreement with the experimental results. This publication provides a brief introduction to the subject matter, followed by a short retrospective of previous efforts and related challenges. The general trends in the numerical analysis of vortex tubes are presented. The conclusions are developed on the basis of the most recent and previously published results of numerical studies. Researchers studying flows in vortex tubes typically use axisymmetric models in both three- and two-dimensional dimensions. However, the authors have repeatedly concluded that none of the available turbulence models can accurately represent the complex fluid dynamics inside a vortex tube. Despite this, the standard k-ε turbulence model is often successfully used to simulate turbulent phenomena and can be considered a basic model for evaluating the characteristics of vortex tubes. Although this model is not without its drawbacks, it can be used to obtain a fairly accurate generalized picture of the distribution of key parameters with satisfactory accuracy and without the need for additional model calibration. Most of the considered turbulence models underestimate (to varying degrees in each individual case) the level of total temperature separation in a Ranque-Hilsch vortex tube. The accuracy of temperature separation calculations can be improved by using more complex models, such as LES vortex-resolving models. However, these models are not an everyday tool for design engineers due to their demanding computational resources and the time required for calculations.For complete and reliable modeling of flow in a vortex tube, a more accurate (than existing) turbulence model is still needed today.