Selected literatures introduction about gas-liquid flow in microchannels

1. Selected literatures introduction about gas-liquid flow in microchannels Reporter: Zhang Weihua Supervisor: Professor XinFeng

2. Contents

3. Fundamentals Flow patterns Mixer geometry Pressure drop

4. Fundamentals Flow patterns Jean-François Manceau et al. New regime of droplet generation in a T-shape microfluidic junction (2013)

6. Fundamentals Mixer geometry K.D.P. Nigam et al. Slug flowin curved microreactors: Hydrodynamic study (2007)

7. Fundamentals Pressure drop

8. Bretherton Bretherton’s analysis is valid for very small liquid film thickness df and in absence of significant inertial and gravitational forces, i.e. Cab →0 and And results in: Aussillous and Quéré: J.C.Schouten et al. Pressure drop of gas–liquid Taylor flow in round micro-capillaries for low to intermediate Reynolds numbers (2009)

9. Kreutzer Kreutzer et al. consider the liquid flow in the slugs to be a fully developed Hagen–Poiseuille flow

10. Mass balance-based Model Fig. 1 Schematic of Taylor flow showing the definitions of the unit cell, gas bubble length Lb and the liquid slug length Ls. The lengths of the nose Lnose and tail Ltailsections of the gas bubble are also indicated

11. Pressure drop Model Accounting for a non-negligible liquid film thickness: The frictional pressure loss in one liquid slug: The pressure drop over a unit cell: The pressure drop over a unit length of channel:

12. Rewritten by: Substituting, then get: And: For a stagnant liquid film: Then:

13. Experimental:

15. Maldistribution Elevated pressure MicrochannelNetwork

16. Maldistribution Elevated pressure Chen Guangwe et al. Gas-liquid two-phase flow in microchannel at elevated pressure(2013)

22. Maldistribution Microchannel Network M. Saber,J.M.Commenge. Microreactor numbering-up in multi-scale networks for industrial-scale applications: Impact of flow maldistribution on the reactor performances. (2007)

23. The frictional pressure drop through the two-scale device: The flow Maldistribution and Standard/Yield deviation defined as: With:

24. Robustness

25. Normalized pressure drop:

26. Microdroplets T-controlled bubble condensation method Luo GS et al. Generation of monodispersedmicrodropletsby temperature controlled bubble condensation processes (2013)

27. Figure 2. Main components of the temperature controlled microfluidic system. (a) The mini-evaporator fabricated from a stainless steel pipe (b) The air bath (bottom-up) fabricated with anodized aluminum. A glass window is placed on the metal shell to observe the inside. (c) The capillary embedded coflowing generators (d) The cooling unit with 2 m long cooling pipe.

30. Simulation Fan LS et al. Experiment and lattice Boltzmann simulation of two-phase gas–liquid flows in microchannels (2007)

31. The simulation was performed on the D2Q9 lattice The number density and momentum of each component: The equilibrium value of the velocity: Where:

32. The interaction force on component σ: The macroscopic variables:

40. Research Orientation