Density destratification by a single bubble plume in long horizontal fluid layers and in a dam lake

Bubble plumes in density stratified liquids induce a narrowly closed convective circulation around them. This localized dynamic process limits the application of bubble plumes to ventilate large aquatic systems experiencing water quality issues, such as reservoirs, lakes, and coastal waters. However, choosing a suitable bubbling condition, i.e. bubble size and gas flow rate, bubble plumes can drive long-range horizontal density currents and ultimately cause the global destratification of the water body. We experimentally investigate how a bubble plume creates a density current that supports the destratification of a strongly two-layer stratified 2 m-long flume. The result leads to the establishment of a mathematical model for predicting the suitable range of the gas flow rate and the time required for the entire destratification of a reservoir. Furthermore, a real-scale experiment in a stratified dam lake of 600 m in horizontal longest length allowed us to confirm the robustness of the model and demonstrate its applicability to aquatic environments.