Author(s)

H. Tanaka & A. Sana

Abstract

The importance of an existing criterion, to distinguish between ordinary and quasi-steady wave boundary layers, has been elucidated by considering two typical field examples. It has been shown that only longer period of oscillation is not sufficient to induce quasi-steady properties, the ratio of boundary layer thickness to the distance from the bottom to free-stream must be used instead, in order to distinguish a quasi-steady wave boundary layer from an ordinary one. 1 Introduction In coastal bottom boundary layers, the oscillatory frictional resistance has been studied by a large number of researchers using various approaches (see e.g. Sleath [1]). All these studies are based on the assumption of small thickness of the boundary layer as co

Keywords