segregation equations дфа д + V. (au) + -(9₁ز $b) (2.27) at дл афо at = д дфа oz (Dodda). дz + V. (سu) + дz a (9bت Øb) дл д = дл ( døb Db дл :) (2.28) In each of these equations, the first term on the left-hand side describes the rate of change of the concentration with time, the second describes the transport of ' due to the bulk flow field, the third is due to segregation (with a typical ab structure) and the term on the right- hand side accounts for diffusive remixing of the particles. The segregation and diffusion rates are defined as Bab]. (2.29a,b S WS ne рож = 9 [² 9a qa = q a* e- qb = 9 [ 2² - - pa* pa* Da - = pb* ρ + ρ pa* D, pax P [+] рож pb* Bba ba], P Db = рож D, (2.30a,b ) and account for both particle-size and particle-density segregation, with density segregation driven by the intrinsic density difference pb* - pa* and size segregation driven by the terms involving Bab and Bba . It is very important to note, however, that ( 2.27 ) and ( 2.28 do not sum to zero, as one might expect. The root cause of this is that the bulk velocity field u is no longer incompressible. Bab= 1 Bŕd³ where C + (h-2) (05& B=0·3744 C = 0.2712 J = $ ' de + øds 1/2 ds6mm, de 19mm h512cm {=250,8m=0.2657 I and. S are a and b in equ (2.27) and 6.28 steady sol's with diffusion and size segregation