会议专题

On the early development of dispersion in flow through a tube with wall reactions

This is a study on numerical simulation of the convection-diffusion transport of a chemical species in steady ow through a small-diameter tube, which is lined with a very thin layer made up of retentive and absorptive materials. The species may be subject to a first-order kinetic reversible phase exchange with the wall material and irreversible absorption at the tube wall. Owing to the velocity shear across the tube section, the chemical species may spread out axially along the tube at a rate much larger than that given by the molecular diffusion; this process is known as dispersion. While the long-time dispersion behavior, well described by the Taylor model, has been extensively studied in the literature, the early development of the dispersion process is by contrast much less investigated. By early development, we mean a span of time, after the release of the chemical into the ow, that is shorter than or comparable to the diffusion time scale across the tube section. To understand the early development of the dispersion, the governing equations along with the reactive boundary conditions are solved numerically using the Flux Corrected Transport Algorithm (FCTA). The computation has enabled us to investigate the combined effects on the early development of the dispersion coefficient due to the reversible and irreversible wall reactions.

early development of dispersion dispersion coefficient wall reactions FCTA

M.W.Lau C.O.Ng

Department of Mechanical Engineering, The University of Hong Kong, Pokfulam Road, Hong Kong,China

国际会议

The Fifth International Conference on Fluid Mechanics(第五届国际流体力学会议)

上海

英文

2007-08-15(万方平台首次上网日期,不代表论文的发表时间)