Search results for " Two.phase flow"

showing 3 items of 3 documents

CFD simulations of dense sloid-liquid suspensions in baffled stirred tanks: Prediction of suspension curves

2011

Mixing of solid particles into liquids within contactors mechanically agitated by stirrers is a topic of primary importance for several industrial applications. A great research effort has been devoted to the assessment of the minimum impeller speed (Njs) able to guarantee the suspension of all particles. Conversely, only little attention has been paid so far to the evaluation of the amount of solid particles that are suspended at impeller speeds lower than Njs. In some cases the loss in available interfacial area between particles and liquid could be reasonably counterbalanced by a decreased mechanical power, making it of interest to evaluate the percentage of suspended solids at different…

EngineeringDrag coefficientEulerian-Eulerian Solid-liquid suspension Partial suspension Drag force Stirred tank Suspension curve Two.phase flow Turbulence modelTurbulencebusiness.industryGeneral Chemical EngineeringSettore ING-IND/25 - Impianti ChimiciMixing (process engineering)Mechanical engineeringGeneral ChemistryMechanicsComputational fluid dynamicsIndustrial and Manufacturing EngineeringImpellerDragEnvironmental ChemistryTwo-phase flowbusinessSuspension (vehicle)
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CFD simulations of dense solid–liquid suspensions in baffled stirred tanks: Prediction of the minimum impeller speed for complete suspension

2012

Abstract In the literature on mechanically agitated solid–liquid systems, several methods are described to estimate the minimum impeller speed Njs at which all particles are suspended, but few studies have been devoted so far to their critical comparative assessment [67] . In the present paper, several alternative Njs prediction methods are applied to CFD results obtained for selected test cases covering a broad range of suspension conditions and impeller speeds. Results are compared with one another and with classic empirical correlations [88] . The aim of the work is to assess the adequacy of different methods for predicting Njs and, more generally, to contribute to a viable CFD-based str…

Settore ING-IND/26 - Teoria Dello Sviluppo Dei Processi ChimiciWork (thermodynamics)Engineeringbusiness.industrySettore ING-IND/25 - Impianti ChimiciGeneral Chemical EngineeringMixing (process engineering)Mechanical engineeringGeneral ChemistryMechanicsStirred tank Multi-fluid model Computational fluid dynamics Solid–liquid two-phase flow Complete suspension speed Sufficient suspension speed Unsuspended solids criterionComputational fluid dynamicsIndustrial and Manufacturing EngineeringControl volumeImpellerEnvironmental ChemistrySuspension (vehicle)Reynolds-averaged Navier–Stokes equationsbusinessContactorChemical Engineering Journal
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RELAP5 simulation of two-phase flow experiments in vertical helical tubes

2010

In the framework of the studies concerning the thermalfluid dynamic phenomena in helicoidal pipes of the innovative nuclear reactor IRIS steam generators, the Department of Nuclear Engineering of the University of Palermo in collaboration with the Politecnico di Torino Department of Energetics has been engaged in a work aimed to adapt, by implementing new suitable models, RELAP5/mod3.2.2β code to simulate the thermalfluid-dynamics and geometries such as the ones involved in helicoidal pipes. In fact this code is based on one-dimensional thermal-hydraulic relationships and presents limitations to model complicated geometry such as helicoidal pipes. Therefore the code was improved with additi…

relaphelical tubes two-phase flowSettore ING-IND/19 - Impianti Nucleari
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