人工粗度の実験的研究 ―イボ型粗度―

Abstract

回定床開水路模型実験水路への適用を目的として, 著者は数年来人工粗度の抵抗特性を実験的に究明することに努め, 粗度要素が線状をなして水路を横切る棲型粗度および溝型粗度について一応の結論を得たが1)・2), さらに, これらとともに人工粗度の代表的形式の一つである点状の粗度要素をもつイボ型粗度について, 若干の実験結果を得たので, ここに報告する。

This paper is a part of the series of the experimental study on the resistance characterof some artificial roughnesses for the purpose of application to open channel models withfixed bed. The experiments were conducted in the 20cm wide and 144m long steel flume with1/500 slope. Roughness elements consisting of vinyl piece, 5mm x 5mm x 6mm, were placed onthe bed of the flume at various longitudinal and transverse spacings. The data are analyzedreferring to the strip roughness described in the previous reports' " - A logarithmic resist-ance formula is developed in which the resistance factor is related to the bight and spacingof the roughness element. The experimental results are compared with those of the investi-gation in W.E.S..