Two-phase computational fluid dynamics assessment of bubble plume in air-diffuser destratification

Area of Science:

• Fluid Dynamics
• Environmental Engineering

Background:

• Bubble plumes are crucial for destratification in stratified fluids.
• Optimizing air-diffuser systems requires understanding complex hydrodynamic behaviors.

Purpose of the Study:

• To develop and validate a two-phase computational fluid dynamics (CFD) model for bubble plume behavior.
• To investigate hydrodynamic flow patterns and energy efficiency in stratified fluids.

Main Methods:

• Developed a two-phase (air-water) CFD model to simulate bubble plume dynamics.
• Validated the model using laboratory experiments in thermally stratified freshwater.
• Analyzed flow patterns and energy conversion efficiency across varying plume numbers.

Main Results:

• The CFD model accurately simulates hydrodynamic behavior and turbulent flow patterns for plume numbers 30-600.
• Energy conversion efficiency increases with plume number, differing from previous findings.
• Observed distinct flow types not aligned with existing plume number regimes, attributed to bubble size.

Conclusions:

• The CFD model offers detailed insights into bubble plume hydrodynamics, surpassing 1D models.
• Bubble size significantly influences flow regimes and energy efficiency in stratified destratification.
• Findings provide a basis for optimizing air-diffuser system design and performance.