OXYGEN-TRANSFER SIMILITUDE FOR VENTED HYDROTURBINE

A similitude relationship for the oxygen transfer that occurs in a ven ted hydroturbine is developed with reference to scaling between a homo logous turbine model and a full-size turbine installation (prototype). Three basic parameters are identified as important for the scaling of oxygen transfer: the liquid film coefficient, the specific surface ar ea, and the contact time. The similitude relation is then developed wi th existing theories on turbine hydrodynamics, bubble hydrodynamics, a nd interfacial mass transfer. The only model-prototype data set curren tly available is used to empirically fit one coefficient and to test t he theory Model-prototype similitude for oxygen transfer is primarily a function of gas-void ratio, rotational speed, and runner diameter wi th diffusivity, surface tension, and density playing a lesser role.