OP-II-3

PP-I-1HYDRODYNAMICS OF TAYLOR FLOW OF GAS-LIQUID SYSTEMSIN MICRO CHANNELS: THEORY AND EXPERIMENTAbiev R.Sh., Lavretsov I.V.St. Petersburg State Technological Institute (Technical University),St. Petersburg, Russia, abiev_r@mail.ruIn last two decades micro technologies and micro equipment are the objects ofgreat interest, in the first place for mixing, heat transfer, extraction, as chemicalreactors for organic and inorganic reactions, as well as lab on a chip for chemical orbiological analysis. Most apparatuses for such processes consist of one or manymicro channels with hydraulic diameter in range 0.3 - 2 mm. It has been revealed thatthe most effective flow mode for mass transfer is Taylor flow (slug or plug flow). Themass transfer rate depends on some hydrodynamic parameters like capillarynumber, bubble velocity and length, liquid slug length etc.In our papers [1-3] a mathematical model (1)-(7), including Aussilous-Quereequation (7), for the gas–liquid slug flow in a capillary is developed (indices "1" and"2" correspond to liquid and gas).⎛ ∂ρ⎜⎝ ∂t∂ρ ∂+∂tτ∂uu∂u∂uuxx θ x x ⎞ ∂2+ ur+ + ux= −∂rr∂θ( ρur) ∂( ρu) ∂( ρu)rr∂r+⎛ ∂u⎝ ∂θr∂θ∂u∂+x r2= μ0 2⎜+ ⎟ =r= r x⎞⎠∂xx∂x⎟⎠∂x( p − ρgxx) + μ∇ ux, (1)= 0 , (2)0 , (3) u 0 , (4)1 =r =Ru1 = ur = R 2 , (5)r =b R bτ1 = τr = R 2 , (6)r =b R bδ 1.34⋅Ca=R 1+3.35⋅Ca2 / 3. (7)2 / 3Using the mathematical model (1)-(7) the velocity profiles in the bubble, film, andliquid slugs are calculated. The experimentally found bifurcational behavior of the slipvelocity of bubbles relative to the two-phase mixture reported in the literature isdescribed and supported by the theory. The boundaries of the existence of bypassand circulation modes of slug flow past bubbles are theoretically substantiated. The218