Diffusion Interaction of Two Particles or Drops

At high Peclet numbers, the diffusion flux to the surface of the first solid particle can be found by solving the conventional diffusion boundary layer equation the presence of the second solid particle influences only by changing the velocity 

Order of magnitude of dimensionless (related to the radius of drops or solid particles) characteristic sizes of regions of diffusion wake in translational Stokes flow at high Peclet number 

Diffusion wake regions Dimensionless distance from the interface, y = r—l Dimensionless distance from the flow axis, h 

Mass exchange of the second solid particle is more complicated. The main role is played by the interaction of the diffusion boundary layer of the second particle with the diffusion wake of the first particle. 

The passage to the limit in this formula is carried out under a constant distance between the solid particles, and the Peclet number is determined on the basis of the characteristic size of the solid particle. 

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