A numerical modelling of gas exchange mechanisms between air and turbulent water with an aquarium chemical reaction

JOURNAL OF COMPUTATIONAL PHYSICS

卷:256

Article

Nagaosa, Ryuichi S.

关键词: Two-compartment model;    Direct numerical simulation;    Turbulent flow;    Gas exchange;    Gas-liquid interface;    Aquarium chemical reaction;    Schmidt number;   

DOI  :  10.1016/j.jcp.2013.08.027

来源: Elsevier

【 摘 要 】

This paper proposes a new numerical modelling to examine environmental chemodynamics of a gaseous material exchanged between the air and turbulent water phases across a gasliquid interface, followed by an aquarium chemical reaction. This study uses an extended concept of a two-compartment model, and assumes two physicochemical substeps to approximate the gas exchange processes. The first substep is the gas-liquid equilibrium between the air and water phases, A(g) reversible arrow A(aq), with Henry's law constant H. The second is a first-order irreversible chemical reaction in turbulent water, A(aq) + H2O -> B(aq) + H+ with a chemical reaction rate kappa(A). A direct numerical simulation (DNS) technique has been employed to obtain details of the gas exchange mechanisms and the chemical reaction in the water compartment, while zero velocity and uniform concentration of A is considered in the air compartment. The study uses the different Schmidt numbers between 1 and 8, and six nondimensional chemical reaction rates between 10(-infinity)(approximate to 0) to 10(1) at a fixed Reynolds number. It focuses on the effects of the Schmidt number and the chemical reaction rate on fundamental mechanisms of the gas exchange processes across the interface. (C) 2013 The Author. Published by Elsevier Inc. All rights reserved.

【 授权许可】

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