Dispersion coefficient for laminar flow in curved tubes

Abstract

The axial dispersion coefficient in a fluid in laminar flow in a tube is generally smaller in a curved tube than in a straight tube, because of the enhancement of lateral transport by secondary flows. In this paper the extent of this reduction is computed using Horn's modification of Aris's method of moments. Dimensional analysis suggests that the most convenient form in which to represent the results is that obtained empirically by Trivedi and Vasudeva. The results presented here cover the whole laminar flow regime, and show the region of applicability of previously computed dispersion coefficients to be limited. The computed dispersion coefficients agree well with previously reported experimental results for small Schmidt numbers; however, discrepancies are present at large Schmidt numbers. Possible causes are discussed.

In Situ Reaction Monitoring of Unstable Lithiated Intermediates through Inline FTIR Spectroscopy

“…MR2 MR3 Tab. 1 compares the three microreactors with respect to the Re 1) , Dn, and Bo numbers (both for straight [33,34] and coiled capillary tubes [35]). These dimensionless parameters depend on the flow rate and are provided for several residence times.…”

Utilization of milli-scale coiled flow inverter in combination with phase separator for continuous flow liquid–liquid extraction processes

“…At higher Dean numbers mixing performance is enhanced [66]. A considerable amount of work has been reported in literature on dispersion in helical coiled tubes for single-phase flow and axial dispersion was found to be considerably lower than that in a straight tube [67][68][69][70][71][72][73][74][75][76][77][78]. Two-phase flow in helical coils has also been studied [79][80][81][82][83][84].…”

Modeling and Simulation of Micro Reactors: Sections 2.6–2.9

“…This aspect was investigated by Daskopoulos and Lenhoff [155] for ducts of circular cross-section. It is therefore helpful to know how hydrodynamic dispersion is modified in a curved channel geometry.…”