Depth-limited oscillatory boundary layers on a rough bottom

Hitoshi Tanaka, Ahmad Sana, Ikuo Kawamura, Hiroto Yamaji

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

An experimental study is carried out to investigate the transformation of oscillatory boundary layer from ordinary to depth-limited one by using an oscillating tunnel with triangular roughness pasted on the top and bottom surfaces. The velocity is measured by one-component LDV. It is proved that only longer period of oscillation is not sufficient to induce depth-limited properties. Instead, the ratio of boundary layer thickness to the distance from the bottom to the free surface must be used in order to distinguish a depth-limited oscillatory boundary layer from an ordinary one. The experimental data for mean velocity, phase difference, fluctuating velocity, friction coefficient and boundary layer thickness are presented in order to elaborate the structure of depth-limited oscillatory boundary layers on a rough bottom. On the basis of the present experiments, a modification has been made in an existing criterion to distinguish between ordinary and depth-limited wave boundary layers. A typical field situation is discussed to show the usefulness of the proposed criterion.

Original languageEnglish
Pages (from-to)85-105
Number of pages21
JournalCoastal Engineering Journal
Volume41
Issue number1-4
Publication statusPublished - 1999

Fingerprint

Rough
Boundary Layer
Boundary layers
Phase Difference
Phase velocity
Friction Coefficient
Tunnel
Roughness
Free Surface
Triangular
Experimental Study
Tunnels
Surface roughness
Experimental Data
Oscillation
Friction
Sufficient
Experiment
Experiments

Keywords

  • Bottom friction
  • Depth-limited oscillatory boundary layer
  • Friction coefficient
  • Long waves

ASJC Scopus subject areas

  • Civil and Structural Engineering
  • Ocean Engineering

Cite this

Tanaka, H., Sana, A., Kawamura, I., & Yamaji, H. (1999). Depth-limited oscillatory boundary layers on a rough bottom. Coastal Engineering Journal, 41(1-4), 85-105.

Depth-limited oscillatory boundary layers on a rough bottom. / Tanaka, Hitoshi; Sana, Ahmad; Kawamura, Ikuo; Yamaji, Hiroto.

In: Coastal Engineering Journal, Vol. 41, No. 1-4, 1999, p. 85-105.

Research output: Contribution to journalArticle

Tanaka, H, Sana, A, Kawamura, I & Yamaji, H 1999, 'Depth-limited oscillatory boundary layers on a rough bottom', Coastal Engineering Journal, vol. 41, no. 1-4, pp. 85-105.
Tanaka, Hitoshi ; Sana, Ahmad ; Kawamura, Ikuo ; Yamaji, Hiroto. / Depth-limited oscillatory boundary layers on a rough bottom. In: Coastal Engineering Journal. 1999 ; Vol. 41, No. 1-4. pp. 85-105.
@article{f8637838288046e5a17ad7c2ec8b4c79,
title = "Depth-limited oscillatory boundary layers on a rough bottom",
abstract = "An experimental study is carried out to investigate the transformation of oscillatory boundary layer from ordinary to depth-limited one by using an oscillating tunnel with triangular roughness pasted on the top and bottom surfaces. The velocity is measured by one-component LDV. It is proved that only longer period of oscillation is not sufficient to induce depth-limited properties. Instead, the ratio of boundary layer thickness to the distance from the bottom to the free surface must be used in order to distinguish a depth-limited oscillatory boundary layer from an ordinary one. The experimental data for mean velocity, phase difference, fluctuating velocity, friction coefficient and boundary layer thickness are presented in order to elaborate the structure of depth-limited oscillatory boundary layers on a rough bottom. On the basis of the present experiments, a modification has been made in an existing criterion to distinguish between ordinary and depth-limited wave boundary layers. A typical field situation is discussed to show the usefulness of the proposed criterion.",
keywords = "Bottom friction, Depth-limited oscillatory boundary layer, Friction coefficient, Long waves",
author = "Hitoshi Tanaka and Ahmad Sana and Ikuo Kawamura and Hiroto Yamaji",
year = "1999",
language = "English",
volume = "41",
pages = "85--105",
journal = "Coastal Engineering in Japan",
issn = "0578-5634",
publisher = "World Scientific Publishing Co. Pte Ltd",
number = "1-4",

}

TY - JOUR

T1 - Depth-limited oscillatory boundary layers on a rough bottom

AU - Tanaka, Hitoshi

AU - Sana, Ahmad

AU - Kawamura, Ikuo

AU - Yamaji, Hiroto

PY - 1999

Y1 - 1999

N2 - An experimental study is carried out to investigate the transformation of oscillatory boundary layer from ordinary to depth-limited one by using an oscillating tunnel with triangular roughness pasted on the top and bottom surfaces. The velocity is measured by one-component LDV. It is proved that only longer period of oscillation is not sufficient to induce depth-limited properties. Instead, the ratio of boundary layer thickness to the distance from the bottom to the free surface must be used in order to distinguish a depth-limited oscillatory boundary layer from an ordinary one. The experimental data for mean velocity, phase difference, fluctuating velocity, friction coefficient and boundary layer thickness are presented in order to elaborate the structure of depth-limited oscillatory boundary layers on a rough bottom. On the basis of the present experiments, a modification has been made in an existing criterion to distinguish between ordinary and depth-limited wave boundary layers. A typical field situation is discussed to show the usefulness of the proposed criterion.

AB - An experimental study is carried out to investigate the transformation of oscillatory boundary layer from ordinary to depth-limited one by using an oscillating tunnel with triangular roughness pasted on the top and bottom surfaces. The velocity is measured by one-component LDV. It is proved that only longer period of oscillation is not sufficient to induce depth-limited properties. Instead, the ratio of boundary layer thickness to the distance from the bottom to the free surface must be used in order to distinguish a depth-limited oscillatory boundary layer from an ordinary one. The experimental data for mean velocity, phase difference, fluctuating velocity, friction coefficient and boundary layer thickness are presented in order to elaborate the structure of depth-limited oscillatory boundary layers on a rough bottom. On the basis of the present experiments, a modification has been made in an existing criterion to distinguish between ordinary and depth-limited wave boundary layers. A typical field situation is discussed to show the usefulness of the proposed criterion.

KW - Bottom friction

KW - Depth-limited oscillatory boundary layer

KW - Friction coefficient

KW - Long waves

UR - http://www.scopus.com/inward/record.url?scp=0010735420&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0010735420&partnerID=8YFLogxK

M3 - Article

VL - 41

SP - 85

EP - 105

JO - Coastal Engineering in Japan

JF - Coastal Engineering in Japan

SN - 0578-5634

IS - 1-4

ER -