Author(s)

M. Kanoh & T. Kuroki

Abstract

In an earlier study to numerically represent the phenomenon described below, we proposed the density diffusion caused by the liquid density ρ, the gravity acceleration g, and the time increment Δt. During field studies, an attempt was made to ameliorate the concentration of oxygen in the lower layer of a few water reservoirs by using a machine that supplies dissolved oxygen (DO), which led to reports of a phenomenon in which the distance reached by the DO-rich water was more than 300 metres despite the very low velocity of the water flow In this report, we investigate the numerical criteria for calculating the density diffusion in a water reservoir by using two-dimensional convective-diffusion equations. Using the signs of the space division h(=Δs), the time increment k(=Δt), the diffusion parameter Γ (= D*k/(h)2), and the Curant number Cr (= V*k/h), we discuss the order estimate for calculating the density diffusion.

Keywords