NUMERICAL SIMULATION FOR WALL EFFECT ON A SPHERICAL PARTICLE SETTLING IN CIRCULAR AND NON-CIRCULAR DUCTS FILLED WITH NEWTONIAN FLUID

Abstract

The objective of this research is to study the wall effect on a spherical particle settling in circular tube and square tube cross section area and compared between them. The effect of bounded wall on drag coefficient expressed by taken a sphere settling along the axis of tubes .The governing equations and the boundary conditions for two types of tubes numerically solved by using Ansys fluent 15 software over a wide range for conditions ,sphere to tube diameter ratio: B(0.1-0.6),Reynolds number:(10-110).One type of shape rigid solid particle was used :sphere settling in two types of container one circular and other non-circular cross section taken square cross section as non-circular tube .Equivalent diameter was used for an equal area circular cylinder to evaluate diameter for square container in this study taken equal area and diameter ratio for circular and square cross section area tube .One type of fluid was used in this study :Newtonian fluid such as water .The results shown that the drag coefficient decrease with increasing Reynolds number because the flow in laminar slip region ,the drag coefficient increase with increasing in the diameter ratio because the present of the bounded wall lead to increase in drag force .The square cross section area tube having drag force greater than circular cross section area tube.