## Abstract

Numerical simulations of 3D flow past two identical

spheres which are held fixed relative to each other at different

separation distances and angles (which describe the deviation from the centre

line of the trailing particle) are carried out. Particle Re = 300 is used

to investigate the dependency of drag and lift coefficients on the separation

distances and the angles. The simulations are performed on a Cartesian grid using the

Volume of Solid (VOS) method to represent the spherical particles. Comparison with

experimental and numerical data shows that method can accurately resolve the

flow field around the spheres and the forces they are subjected to.

Results are focused on the behaviour of forces (drag and lift) affected by the presence

of another particle. The drag of the reference and secondary sphere is greatly

affected when they are placed in tandem arrangement at a gap of 2.5 - 3d and 1.5d respectively. Similarly the

lift of the reference sphere is greatly affected in the arrangement when

the spheres are placed in the symmetry plane at gap of 1.5d and angle of

45 degrees. The effect of both forces decrease as the gap is increased in all

arrangements. The flow becomes unsteady and periodic at a separation distance of

3d for the tandem case. Irregular vortex shedding is observed at large

separation distances 6 - 9d. The results for forces coefficients and the vortex shedding show great

resemblance for the cases when the spheres are placed in symmetry plane and

plane perpendicular to it at same gaps and angles. The characteristics of the flow, wake and the vortical structures are investigated in detail in the present study.

spheres which are held fixed relative to each other at different

separation distances and angles (which describe the deviation from the centre

line of the trailing particle) are carried out. Particle Re = 300 is used

to investigate the dependency of drag and lift coefficients on the separation

distances and the angles. The simulations are performed on a Cartesian grid using the

Volume of Solid (VOS) method to represent the spherical particles. Comparison with

experimental and numerical data shows that method can accurately resolve the

flow field around the spheres and the forces they are subjected to.

Results are focused on the behaviour of forces (drag and lift) affected by the presence

of another particle. The drag of the reference and secondary sphere is greatly

affected when they are placed in tandem arrangement at a gap of 2.5 - 3d and 1.5d respectively. Similarly the

lift of the reference sphere is greatly affected in the arrangement when

the spheres are placed in the symmetry plane at gap of 1.5d and angle of

45 degrees. The effect of both forces decrease as the gap is increased in all

arrangements. The flow becomes unsteady and periodic at a separation distance of

3d for the tandem case. Irregular vortex shedding is observed at large

separation distances 6 - 9d. The results for forces coefficients and the vortex shedding show great

resemblance for the cases when the spheres are placed in symmetry plane and

plane perpendicular to it at same gaps and angles. The characteristics of the flow, wake and the vortical structures are investigated in detail in the present study.

Original language | English |
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Title of host publication | Proceedings of the 6th International Conference on Multiphase Flow |

Editors | Martin Sommerfeld |

Publication status | Published - 2007 |

Event | 6th International Conference on Multiphase Flow, 2007 - Leipzig, Leipzig, Germany Duration: 2007 Jul 8 → 2007 Jul 13 Conference number: 6 |

### Conference

Conference | 6th International Conference on Multiphase Flow, 2007 |
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Abbreviated title | ICMF 2007 |

Country/Territory | Germany |

City | Leipzig |

Period | 2007/07/08 → 2007/07/13 |

## Subject classification (UKÄ)

- Fluid Mechanics and Acoustics