kth_logo.gif

Artikel

The interaction among two fixed spherical particles in an oscillatory flow

Författare: Prahl Wittberg, L., Revstedt, J., Fuchs, L.F.
Dokumenttyp: Konferens
Tillstånd: Publicerad
Tidskrift: 5th Conf. on Bluff Body Wakes and Vortex-Induced Vibrations, Dec 12-15, 2007, Bahia, Brazil
Volym:   
År: 2007

Abstract

Simulations of the flow around a pair of spherical particles subjected to either a uniform or a pulsating inflow are performed. The purpose is to study the effects a time dependent velocity profile as well as the inclusion of an additional particle will have on force and flow characteristics. For Reynolds number of 100 applying both a uniform and a pulsating inflow, the distance between the particles is varied from 1.5-6.0D and the separation angle is 0-90° using 1.5D and 15° increments, respectively. Moreover, for pulsating inflow, Reynolds numbers of 300 and 600 are studied to capture the instability characteristics for particles placed in tandem formation, using the same distance range as for Re = 100. Furthermore, the Strouhal number of the sinusoidal inlet flow is varied between 0.05 and 0.2 for Re = 100, 300 and 600. The Volume of Solid (VOS) method, an approach based on the Volume of Fluid (VOF) method, is used in order to describe the particles. In order to validate VOS, the approach is compared with both experimental and numerical data found in literature regarding the drag force on a single particle for a wide range of Reynolds numbers. The results show a strong dependency on inflow frequency. For Reynolds number of 100, the drag force is similar for both inflows tested with strong dependency on relative particle position, a feature not as significant for the higher Reynolds numbers.