Moving Speed of Bottom Drift Net

Abstract

An experiment on a bottom drift net was conducted in a 25m long circulating water channel.It was observed that the relative speed of the net against the current speed increased and the net height lowered with increasing current spedd. The result suggested that the flow in the water channel was not uniform but due to a considerably thick bottom boundary layer. It was ascertained that the approximate formula on the moving speed of a net which had been derived in their previous reports by the author and his collaborator on the hypothesis that the current was uniform coincided with the experimental result, subject to the flow speed averaged uo to the net height from the bottom.