Abstract
Gravity current is a very important phenomenon for the marine environment.
In order to understand overall structure of them, it is necessary to perform simultaneous measurement of front part and outer part around the nose. The aims of this paper were performing highly precise measurement of giving density information with color information.
As the experimental technique, neutral buoyancy particles of two colors were prepared for the fluid of each density and dispersed into each density fluid. Particle images are visualized by a laser sheet light source, and particles image are acquired with a high-speed video camera. The values in RGB color space are obtained from the picture and they are changed into the values in HSV color space. The images are separated to two colors is created by hue value threshold.
Velocity distributions are obtained from those pictures, using PIV technique of Hiraku et al.
As a result, it is shown that simultaneous velocity measurements of the front part and outer part using the each particle in each density are succeeded. Overall 2-dimensional velocity distribution has been understood.
