The interaction of mechanically generated turbulence and interfacial films with a liquid phase controlled gaslliquid transport process

Abstract

The liquid phase rate-controlled transport of C 0 2 across a gas/liquid interface into water was studied using a non-invasive laser-induced fluorescence (LIF) technique. Turbulence in the liquid layer was generated by a vertically-oscillating grid. The CO,/water interface was cleaned by removal of surface water with additive-free lens paper, or 100% rayon cloth followed by surface vacuuming with a glass Pasteur pipette. The liquid phase mass transfer coefficient k, was measured under conditions of varying turbulence intensity and scale for each surface cleaning procedure. Transport rates were also measured for an uncleaned surface and in the presence of a deliberately created organic monolayer. All of the results were used to test the surface renewal models of Fortescue and Pearson and Lamont and Scott. A model for wind-dominated gasiliquid transfer developed by Cohen was used to relate the present data to k, measurements for gas exchange in wind tunnels. This comparison indicates that wind tunnel results may be related to stirred-tank experiments using the turbulent dissipation rate c. and a surface renewal model.

Laboratory Heat Flux Estimates of Seawater Foam for Low Wind Speeds

“…Natural, filtered seawater was used in the tank for all tests, and sodium hypochlorite was periodically used to control bacterial growth and contamination. Prior to the start of measurements on a given day, the water surface was cleaned of dust and surfactants through suctioning and physical wiping of the surface with lint-free optical paper [38]. A layer of saltwater foam approximately 1.7 cm thick was generated by forcing compressed laboratory air at a rate of 0.4 l s −1 that had been filtered to remove water and oil through a submerged diffuser in the tank.…”

Effects of Salinity on Surface Lifetime of Large Individual Bubbles

“…Table 2 summarizes the experimental conditions. A salinity range of 2-40 psu was chosen to span values observed from lakes to estuaries to the open ocean. Salinity differences were achieved using laboratory-grade sodium chloride (NaCl) without additional cleaning procedures [21]. The salinity of the water was varied in steps of δS ∼ = 4-6.5 psu by adding an appropriate amount of salt to the water volumes used in each experiment.…”

Estimation of turbulence-dissipation rates and gas-transfer velocities in a surf pool: Analysis of the results from WABEX-93

“…In support of Equation 2, Asher and Pankow (1986) found that for carbon dioxide (COJ scaled Iineariy with e". They also found B to be in the range 0.65 to 1.2, depending on cleanliness of the water surface.…”