Mixing and Bimolecular Reaction Kinetics in a Plane Poisseulle Flow

Content Provider	Semantic Scholar
Author	Anmala, Jagadeesh Kapoor, Vivek
Abstract	Mixing and a nonlinear bimolecular chemical reaction (reactant A + reactant B → product; reaction rate r = κc1c2) in laminar shear flow are investigated. It is found that asymptotically the dominant balance between the rates of production and dissipation of the mean-squared concentration fluctuations (σ 2 c1 , σ 2 c2) and crosscovariance of concentration fluctuations (c1c2) occurs under nonreactive and reactive conditions. Longitudinal dispersion of the cross-sectional averages (C1, C2), and variances and the cross-covariance of reactant concentrations can be asymptotically quantified by the classic Taylor dispersion coefficient (D) even under reactive conditions. The characteristic time-scale (τ ) over which molecular diffusion dissipates concentration variance and the cross-covariance of reactant concentrations is also shown to be the same under nonreactive and reactive conditions. A variational estimate of τ is shown to be close to the values inferred from detailed numerical simulation. The production-dissipation balance implies that the cross-sectional averaged reaction rate follows r = κef f C1C2 and κef f ≈ κ [ 1 + 2Dτ ∂ ln C1 / ∂x ) ( ∂ ln C2 / ∂x )] . The effective reaction rate parameter (κef f ) is higher than that of well-mixed batch test reaction rate constant (κ) for initially overlapping species and κef f is smaller than κ for initially non-overlapping species.
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Alternate Webpage(s)	https://page-one.springer.com/pdf/preview/10.1007/s10494-011-9369-5
Language	English
Access Restriction	Open
Content Type	Text
Resource Type	Article