Dispersion of solute in straining flows and boundary layers

TL;DR

This paper analytically investigates solute dispersion in steady laminar axisymmetric flows with axial inflow and radial outflow, focusing on large-time behavior and eigenvalue dependence.

Contribution

It provides an analytical study of solute dispersion in specific flow configurations, highlighting large-time dispersion characteristics and eigenvalue effects.

Findings

Concentration decays exponentially over time.

Eigenvalues depend on flow parameters.

Large-time dispersion behavior characterized analytically.

Abstract

Solute dispersion due to an instantaneously released source in steady, laminar, axisymmetric flows with an axial inflow and radial outflow is investigated analytically. Attention is given to large-time characteristics of dispersion, where the concentration reduces in proportion to $e^{-2\lambda \tau}$, where $\lambda$ is an eigenvalue that depends on the axial inflow and $\tau$ is the time measured in units of axial-diffusion times. Prospects of some other flows are also considered.