Mean Velocity of Nonisotropic Particles Falling in a Fluid

Mean Velocity of Nonisotropic Particles Falling in a Fluid 

The mean flow rate velocity (U) of a particle, which is obtained in a large number of experiments when an arbitrarily oriented particle falls in a fluid, is determined for the Stokes flow by the formula [179]  

The average drag force acting on an arbitrarily oriented particle falling in fluid is given by 

Formulas (2.6.35)-(2.6.37) are important in view of some problems of Brownian motion. 

In the special case of a spherical particle, one must set V - 7ra3 and K = 6ira in (2.6.35). 

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