Indexing gas transfer in self-aerated flows

An indexing relationship, used to index and directly compare measurements, is developed for liquid phase-controlled gas transfer in self-aerated flows from theoretical considerations. The indexing relation is shown to describe temperature effects as well as existing equations that use fitted coefficients. The relation may be used to index adsorption and volatilization rates of any compound exhibiting liquid phase controlled gas transfer and may be used to compare the gas transfer measurements of different compounds. It is proposed that the relationship be used to index liquid phase controlled gas transfer measurements in self-aerated flows to a common reference temperature, 20° C, and to a gas, oxygen, most often used in gas transfer experiments. The indexing relationship is also shown to be valid for any bubbly flow where the gas transfer is predominantly across the bubble interface, such as occurs with aeration bubblers.