MULTIPHASE FLOW
Multiphase flow
Multiphase flows in which more than two phases exist are encountered in a wide range fields of mechanical, chemical, civil, nuclear, biological, environmental and aerospace engineering, and our main purpose is to understand their physics and provide valuable insights to industrial problems; Processing System (e.g., liquid chemical reactor, bioreactor, air-lift system), and Biological and Environmental System (e.g., blood flow, respiratory system, weather change). Understanding their physics is very important because of the significant impact on the safety and efficiency of the thermal-fluid systems listed above.
1. Semiconductor Wafer Cleaning Processes
(1) Liquid film analysis through optical calibration
Experimental setup
Raw image of liquid film on a rotating wafer
Liquid film thickness
(2) Analyzing droplet generation mechanisms in semiconductor cleaning processes
Dynamic schematic of edge-generated droplet impact on wall
Angle(θ) distribution(PDF) of edge-generated droplets
Angle(θ) distribution(PDF) of post-collision droplets
2. Spreading dynamics of droplet with rotation
Experimental setup
Visualizing and processing the rotation of a droplet in the air
Spreading Progression of a Rotating droplet over time
3. Dual-nozzle Atomization
Experimental setup
Liquid atomization process
The classification of flow regimes
4. Characteristics of LSFO(Low Sulfur Fuel Oil)
Hundred of meter scale oil spreading simulation
Tens of km scale oil spreading simulation
Viscometer
Experimental equipment
Wind induced oil spreading image at the free surface
Time history image of oil spreading (wind speed=3.5m/s, water temp.=25℃ )
5. Global water droplet removal
Equation of motion (for moving droplet)
Moving droplet shadowgraphy & setup
Background airflow (temporally and spatially accelerated)
6. Water entry of spheres
The water entry phenomena of roughened spheres (non-cavity-forming case)
The water entry phenomena of roughened spheres (cavity-forming case)
The cavity and splash outlines of roughened spheres (The black line has rougher surfaces)
6-1. Laser-induced cavity control behind a body of water entry
Experimental setup for laser irradiation on the sphere
Change of cavity bubble according to surface temperature (Shallow seal)
Change of cavity bubble according to surface temperature
Change of cavity bubble according to surface temperature (Deep seal)
Change of cavity bubble according to surface temperature
7. Gas-solid fluidization
Experimental setup for two-dimensional gas-solid fluidized-bed
Contour of the time average gas and solid phase bubbling-bed(left); turbulent bed(middle); fast-fluidization(right)
Pressure fluctuation near the inlet while increasing the gas flux
8. Oil/water separation
The two-dimensional simulation of the oil/water separator (ANSYS, CFX)
New oil-water separation design
The time sequence of oil/water separation process