Abstract
Velocity fields of a spot vortex flow that happens spontaneously in the turbulent flow in a bubbling vessel are measured by using an improved defocus method. A new method is developed by improving the defocus method that can measure three-dimensional position of particles using a single camera.
Performance of the new method is expanded in measurement range and in applicability to dense distribution of particles by introducing a color separation technique to the method. The spatial resolution of the method is less than 0.5mm in z-direction at the measurement distance of 380 mm.
