Home About us Contact
|
Home About us Contact | ||
|
|
||
Vane Geometry (vane + geometry)
Selected AbstractsOSCILLATING VANE GEOMETRY FOR SOFT SOLID GELS AND FOAMSJOURNAL OF TEXTURE STUDIES, Issue 6 2002C. SERVAIS ABSTRACT Several relationships between the torque and the stress exist for the vane geometry, but only a few equations have been proposed for the relationship between angular displacement and strain. In this study, an expression based on the infinite gap approximation for concentric cylinders is used and well-defined reference data are compared to oscillating vane data to validate the assumptions used. Gelatin gels are used for their property to stick to the wall and carrageenan gels are used to show that wall slip does not occur with oscillating vanes in serrated cup geometries. Shaving foams are used as a model low density, time and shear stable foam, which resists irreversible damage when loaded between serrated parallel plates. Results show that the assumptions used for the determination of stress and strain with the vane provide material viscoelastic properties that are not significantly different from reference values as obtained with concentric cylinders and parallel plates. [source] Experimental study of the hydraulic operation of an annular centrifugal contactor with various mixing vane geometriesAICHE JOURNAL, Issue 8 2010Kent E. Wardle Abstract The annular centrifugal contactor is a combination mixer/centrifuge that has been developed for solvent extraction processes for recycling used nuclear reactor fuel. The experimental observations presented were part of a simulation-focused research effort aimed at providing a more complete understanding of the fluid flow within these contactors to enable further advancements in design and operation of future units and greater confidence for use of such contactors in a variety of other solvent extraction applications. Laser doppler velocimetry (LDV), particle image velocimetry (PIV), pressure measurements, and high-speed video imaging for a range of flow rates and rotor speeds were performed to characterize the flow of water in the annular mixing region of the contactor using three different mixing vane geometries. It was found that the geometry of the mixing vanes has a significant impact on the annular liquid height and general flow in the contactor mixing zone. © 2009 American Institute of Chemical Engineers AIChE J, 2010 [source] Analysis of the effect of mixing vane geometry on the flow in an annular centrifugal contactorAICHE JOURNAL, Issue 9 2009Kent E. Wardle Abstract The annular centrifugal contactor is a compact mixer/centrifuge developed for solvent extraction processes for recycling used nuclear fuel. This research effort couples computational fluid dynamics (CFD) modeling with a variety of experimental observations to provide a valid detailed analysis of the flow within the centrifugal contactor. CFD modeling of the free surface flow in the annular mixing zone using the volume-of-fluid method combined with large eddy simulation of turbulence was found to have very good agreement with the experimental measurements. A detailed comparative analysis of the flow and mixing with different housing vane geometries (four straight vanes, eight straight vanes, and curved vanes) was performed. Two additional variations on the eight straight vane geometry were also simulated. This analysis determined that at the simulated moderate flow rate the four straight mixing vane geometry has greater mixing and fluid residence time as compared to the other mixing vane configurations. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] Starch-lipid composites in plain set yogurtINTERNATIONAL JOURNAL OF FOOD SCIENCE & TECHNOLOGY, Issue 1 2009Mukti Singh Summary Starch-lipid composites (SLC) were used to replace milk solids in yogurt mixes. The effects of the SLC on the yogurt fermentations and rheology were studied. The rate of fermentation was evaluated by the change of pH during the fermentation of yogurt. The syneresis of yogurt was observed over 3 weeks of storage. Small amplitude oscillatory shear flow measurements of the storage modulus, the loss modulus, and the loss tangent were obtained using a vane geometry. Yogurt mixes with milk solids partially replaced by SLC fermented at a similar rate than as with no milk solids replaced. Initial viscosity was higher for yogurt mixes with higher levels of SLC. The higher initial viscosity did not affect the gel structure. The addition of SLC above a level of 3% strengthened the gel and resulted in no syneresis for yogurt samples stored for 3 weeks at 4 °C. [source] Analysis of the effect of mixing vane geometry on the flow in an annular centrifugal contactorAICHE JOURNAL, Issue 9 2009Kent E. Wardle Abstract The annular centrifugal contactor is a compact mixer/centrifuge developed for solvent extraction processes for recycling used nuclear fuel. This research effort couples computational fluid dynamics (CFD) modeling with a variety of experimental observations to provide a valid detailed analysis of the flow within the centrifugal contactor. CFD modeling of the free surface flow in the annular mixing zone using the volume-of-fluid method combined with large eddy simulation of turbulence was found to have very good agreement with the experimental measurements. A detailed comparative analysis of the flow and mixing with different housing vane geometries (four straight vanes, eight straight vanes, and curved vanes) was performed. Two additional variations on the eight straight vane geometry were also simulated. This analysis determined that at the simulated moderate flow rate the four straight mixing vane geometry has greater mixing and fluid residence time as compared to the other mixing vane configurations. © 2009 American Institute of Chemical Engineers AIChE J, 2009 [source] OSCILLATING VANE GEOMETRY FOR SOFT SOLID GELS AND FOAMSJOURNAL OF TEXTURE STUDIES, Issue 6 2002C. SERVAIS ABSTRACT Several relationships between the torque and the stress exist for the vane geometry, but only a few equations have been proposed for the relationship between angular displacement and strain. In this study, an expression based on the infinite gap approximation for concentric cylinders is used and well-defined reference data are compared to oscillating vane data to validate the assumptions used. Gelatin gels are used for their property to stick to the wall and carrageenan gels are used to show that wall slip does not occur with oscillating vanes in serrated cup geometries. Shaving foams are used as a model low density, time and shear stable foam, which resists irreversible damage when loaded between serrated parallel plates. Results show that the assumptions used for the determination of stress and strain with the vane provide material viscoelastic properties that are not significantly different from reference values as obtained with concentric cylinders and parallel plates. [source] LDA Velocity Measurements of High-Viscosity Fluids in Mixing Vessel with Vane Geometry ImpellerTHE CANADIAN JOURNAL OF CHEMICAL ENGINEERING, Issue 6 2007Lidija Slemenik Perse Abstract The object of this work was to measure the velocity field in non-Newtonian fluids inside mixing vessel. The six-bladed vane rotor used for mixing was designed from rotating vane geometry of a sensor system, commonly used for rheometrical measurements of complex fluids (Barnes and Nguyen, J. Non-Newtonian Fluid Mech. 98, 1-14 (2001); Schramm, 1994). During mixing, the viscosity was determined by measuring the torque at different impeller speeds, and compared to rheologically obtained shear dependent viscosity. The velocity field was determined by LDA measurements at twelve places inside mixing vessel. It was observed that axial and radial component of the velocity were insignificant at all measurement points. On the other hand, the results showed the periodic nature of tangential component of the velocity, which was confirmed with computer-aided visualization method. Ce travail avait pour objectif de mesurer le champ de vitesse dans des fluides non newtoniens dans un réservoir de mélange. Le rotor à six pales utilisé pour le mélange a été conçu d'après la géométrie des ailettes rotatives d'un système de senseurs, communément utilisés dans les mesures rhéométriques de fluides complexes (Barnes and Nguyen, J. Non-Newtonian Fluid Mech. 98, 1-14 (2001); Schramm, 1994). Lors du mélange, on a déterminé la viscosité en mesurant le couple à différentes vitesses de turbine, puis on l'a comparée à la viscosité de cisaillement obtenue rhéologiquement. Le champ de vitesse a été déterminé par des mesures LDA à douze positions dans le réservoir de mélange. On a observé que la composante axiale et radiale de la vitesse était négligeable pour tous les points de mesure. Par ailleurs, les résultats montrent la nature périodique de la composante tangentielle de la vitesse, ce qui est confirmé par une méthode de visualisation assistée par ordinateur. [source] | ||||||||||||||||||||||