I - PRESENTATION
 
 
 
 

We can do several assumptions:

• the flow is stationnary and axisymmetric
• the bubble stays motionless and spheric

We suppose mass transfert across bubble-air interface is null. Therefore, the corresponding boundary condition is :
 
 

Moreover, the viscosity of water is much more important than the viscosity of air, it involves :
 
 

This means the shear stress vanishes on the air - water interface.
 
 
 

The definition of the two following numbers allows  to classify the different types of diphasic flows :
 
 

For a flow of liquid around a gas particle,  we have :

(indeed, it is equal to 0.017)
 
 
 

II - THEORICAL RESULTS
 
 

In order to verify (or not) validity of FLUENT computation, we  use some theorical results.
 
 

We can define Reynold's number with  following characteristics :
 
 

• Re <<1 : Stocke's solution:

Hence, we deduce :
 

         with the approximation : 
 
 
 

• Re = or < 1 : Weak inertial effects:

• Re>1 : Major inertial effects - potential flow :

Comment: Contrary to a flow around a  solid sphere, a flow around a spheric bubble don't remove for any Re. We hope this result will be verified.
 
 

III- PHYSICAL PARAMETERS