Visualization

 

We utilize visualization techniques to understand fluid mechanics problems. Also, we work on developing flow visualization techniques as well.

 

 
Tomographic Particle Image Velocimetry

 

To measure 3D-3C velocity vector components, four CCD cameras are used to observe one target. All cameras are installed under the microscope. There is a only one objective. This setup is very unique to measure micro flows.

Kim et al., "Full 3D-3Cvelocity measurement inside a liquid immersion droplet," Exp. Fluids 51(2), 395 (2011)
Kim et al., "Comparison of Tomo-PIV and 3D-PTV for microfluidic flows," Meas. Sci. Technol. 24(2), 024007 (2013)
 
Schlieren Method

 

We use a Schlieren method to visualize a flow field without using tracer particles. The left hand size example presents the turbulent buoyant flow above the hot plate. This method can be used to investigate flow physics where the density or refractive index difference exists.
 
Polarized Light Microscopy

 

This measurement method can be widely used to look a hidden structure, e.g. internal structure of materials and stresses on the complex liquids. For example, on the left, one image is for the regular bright-field image and the other is for the polarized light image. The objects are liquid crystals.