Fall velocity for a large Reynolds number

When the Reynolds number is large, the viscous term is negligible in [3.9]. The Euler number is of the order of 1, since we are in the situation described by [3.10]. The pressure scale is  

Since the Reynolds number is large, the pressure force (equation [3.18]) outweighs the viscous force (equation [3.17]). The hydrodynamic force is  

The equilibrium between the forces exerted on the ball (equation [3.13]) now leads to Newton s law  

5 This category of flows, called creeping flows , is abundantly documented, in particular for lubrication problems. Chapter 16 discusses creeping flows around a small particle. 

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