Eventos Anais de eventos
12th Spring School on Transition and Turbulence
THE TURBULENCE DAMPING EFFECT ON THE SLUG FLOW MODELING
Harlley Henrique Parno , SC , Brazil
Co-Authors: Harlley Henrique Parno, Bruna Iten Bittelbrunn, Carla Nayara Michels dos Santos, Sarah Laysa Becker, Christine Boos, Celso Murilo dos Santos, Wladir Pedro Martignoni, Henry França Meier
Presenter: Harlley Henrique Parno
The slug flow is one of the most complex flow patterns due to the unstable behavior of the phase distribution. This pattern occurs in a wide range of flow rates and is therefore observed in different industrial processes. The prediction and understanding of the hydrodynamic parameters of this flow regime has significant engineering value. In this context, Computational Fluid Dynamics (CFD) has been shown to be an efficient tool for the prediction of this type of flow. However, to ensure the accuracy of the numerical solution, adequate modeling in the transfer of interfacial properties is necessary One of the most important transfers that take place at the interface is the transfer of moment between phases. Therefore, it is necessary to use a robust approach to model the gas-liquid interface region. The aim of this study is to evaluate the effect of adding the damping of turbulent diffusion at the interface on the modeling of flow. For this, different cases of simulations were elaborated for a pipe with 2 meters in length and 26 mm inner diameter. In all cases the multiphase approach used was the Volume of Fluid (VOF) with the Geo-Reconstruct scheme. The interface between the fluids are modeled with constant surface tension equal 0.0728 N/m. The discontinuities present at the interface was treated in a “continuous surface stress” (CSS) manner. The turbulence was modeled using k-SST with and without the turbulence damping. The independence of the numerical solution in relation to the grid was evaluated by the Grid Convergence Index (GCI) method in which four levels of grid were used. Preliminary results show that in cases run with the turbulence damping a better representation of the flow pattern morphology is obtained. Regarding the quantitative parameters, the prominent frequency of the Power Spectro Density (PSD) and the amplitude of the pressure signal is under-predicted when the turbulence damping is not used.
Slug Flow, Interfacial Modeling, turbulence damping