Destratification Induced by Bubble Plumes

Destratification is an alternative for improving the overall quality, particularly dissolved oxygen content, of a stratified reservoir. Pneumatic systems have been used most often for providing the energy needed to destratify a water body. However, there are no means to evaluate the long-term operation of a destratification system. Under contract, the St. Anthony Falls Hydraulic Laboratory, University of Minnesota, developed a subroutine entitled BUBBLES that simulates the destratification of a lake or reservoir by an air bubble diffuser. This subroutine was added to CE-THERM-RI and used to account for mixing that occurs in a lake or reservoir caused by a pneumatic destratification system. CE-THERM-Rl contains the thermal analysis portion of CE-QUAL-R1 and is used to simulate the water and heat budgets of a water body. This report describes the development of BUBBLES and its incorporation into CE-THERM-R1. In BUBBLES, the reservoir is divided into a near field and a far field. 'Me near-field model includes the bubble plume and the flow in its vicinity. The far-field model treats the rest of the reservoir and considers the flow from the plume toward the lake and from the lake toward the plume. The far-field model is coupled with CE-THERM-RL to simulate water and heat budgets of the water body. Bubble plume, Pneumatic, Destratification, Reservoir, Diffuser, Water quality, Lake.