Improved Atomization via a Mechanical Atomizer with Optimal Geometric Parameters and an Air-Assisted Component

Area of Science:

• Mechanical Engineering
• Fluid Dynamics
• Combustion Science

Background:

• Liquid atomization is crucial for efficient energy conversion in systems like microturbines.
• Reducing energy consumption in atomization processes is a key technological goal.
• Existing atomizers face challenges with low inlet pressure and wide power supply ranges.

Purpose of the Study:

• To investigate the atomization characteristics of a novel mechanical atomizer with optimized geometry and a preliminary swirl stage.
• To evaluate the performance enhancement achieved by incorporating an air-assisted swirl chamber.
• To determine the influence of atomizer parameters on droplet size reduction.

Main Methods:

• Design and testing of a mechanical atomizer with optimized geometric parameters.
• Integration and testing of an air-assisted swirl chamber at the atomizer exit.
• Measurement of droplet diameters (D and D32) under varying water and air supply pressures.
• Analysis of the air-liquid ratio (ALR) effect on atomization.

Main Results:

• The optimized mechanical atomizer achieved droplet diameters of 80-40 µm at 2-5 bar water pressure.
• The addition of an air swirl chamber reduced droplet sizes significantly.
• At an ALR of 1, water pressure of 2.5-3 bar, and air pressure of 0.35-1 bar, D32 drops of 20-30 µm were achieved.
• Mechanical atomizer parameters showed a greater impact on droplet size than air swirl chamber characteristics.

Conclusions:

• The novel air-assisted atomizer design offers superior spray performance and reduced droplet sizes.
• Optimized mechanical atomizer geometry is critical for effective atomization, even with air assistance.
• The study recommends specific operating parameters (ALR ≈ 1, air supply pressure up to 1 bar) for efficient air-assisted atomization.