Abstract
A method to obtain two dimentional distribution of Richardson number is proposed. The distribution of density is visualized by dye (methylene blue). a photograph of dye distribution is taken with a plane light source placed on the opposite side of the experimental channel. Standard solutions of dye are placed on the channel for calibration. The distribution of velocity is visualized by hydrogen bubble method. photographed with a slit-light from the bottom of the channel. Photographs of dye and hydrogen bubbl es are taken alternatively.
These photographs are processed by a video camera. an AD converter. an image memory and apersonal computer to yield 512×480×8 bit intensity data. The intensity data are processed by a universal computer to calculate the distributions of density. velocity and Richardson number. A rising velocity of hydrogen bubbles is corrected by iterative calculations, a spline interpolation is applied to the horizontal direction, the equation of continuity is used to obtain the vertical component of velocity.
An application of this method on density current is shown.
