Geometry and migration characteristics of bedforms under waves and currents. Part 2: Ripples superimposed on sandwaves

Yovanni A. Cataño-Lopera, Marcelo H. García

Research output: Contribution to journalArticle

Abstract

This paper presents results of a series of detailed measurements of geometric and migrating characteristics of ripples superimposed upon sandwaves under the action of combined waves and currents. Velocity measurements within the fluid, surface wave characteristics and 3D mapping of the bottom were recorded with an Acoustic Doppler Velocimeter (ADV), an acoustic water level sensor and a 32 composite element array of sub-aquatic acoustic sensors, respectively. Bottom records were statistically analyzed to obtain height, length and migration rates of ripples. Experiments examined ripple heights and wavelengths for the mobility factors (as defined in Eq. (4)) and the Reynolds wave number within the ranges 10 < ψ < 88 and 16 × 103 < Rew < 5 × 105, respectively. Measured values were compared with laboratory and field data together with semi-empirical and analytical formulae from the literature. Good correlation was obtained when plotting measured ripple length and length in dimensionless form as a function of the Reynolds wave number Rew. Under a given hydraulic condition, it was observed that ripples with different geometric characteristics may coexist at different locations over the sandwave. Ripple steepness is presented as a function of the Shields parameter although characterized with rather large scatter. Finally, average ripple migration speed is presented as a function of the Shields parameter and the mobility number.

Original languageEnglish (US)
Pages (from-to)781-792
Number of pages12
JournalCoastal Engineering
Volume53
Issue number9
DOIs
StatePublished - Jul 1 2006

Fingerprint

Acoustics
Geometry
Velocimeters
Sensors
Water levels
Velocity measurement
Surface waves
Hydraulics
Wavelength
Fluids
Composite materials
Experiments

Keywords

  • Bedforms
  • Ripples
  • Sediment transport
  • Statistical analysis
  • Waves plus currents

ASJC Scopus subject areas

  • Environmental Engineering
  • Ocean Engineering

Cite this

Geometry and migration characteristics of bedforms under waves and currents. Part 2 : Ripples superimposed on sandwaves. / Cataño-Lopera, Yovanni A.; García, Marcelo H.

In: Coastal Engineering, Vol. 53, No. 9, 01.07.2006, p. 781-792.

Research output: Contribution to journalArticle

@article{e343362850904184972db561882425a2,
title = "Geometry and migration characteristics of bedforms under waves and currents. Part 2: Ripples superimposed on sandwaves",
abstract = "This paper presents results of a series of detailed measurements of geometric and migrating characteristics of ripples superimposed upon sandwaves under the action of combined waves and currents. Velocity measurements within the fluid, surface wave characteristics and 3D mapping of the bottom were recorded with an Acoustic Doppler Velocimeter (ADV), an acoustic water level sensor and a 32 composite element array of sub-aquatic acoustic sensors, respectively. Bottom records were statistically analyzed to obtain height, length and migration rates of ripples. Experiments examined ripple heights and wavelengths for the mobility factors (as defined in Eq. (4)) and the Reynolds wave number within the ranges 10 < ψ < 88 and 16 × 103 < Rew < 5 × 105, respectively. Measured values were compared with laboratory and field data together with semi-empirical and analytical formulae from the literature. Good correlation was obtained when plotting measured ripple length and length in dimensionless form as a function of the Reynolds wave number Rew. Under a given hydraulic condition, it was observed that ripples with different geometric characteristics may coexist at different locations over the sandwave. Ripple steepness is presented as a function of the Shields parameter although characterized with rather large scatter. Finally, average ripple migration speed is presented as a function of the Shields parameter and the mobility number.",
keywords = "Bedforms, Ripples, Sediment transport, Statistical analysis, Waves plus currents",
author = "Cata{\~n}o-Lopera, {Yovanni A.} and Garc{\'i}a, {Marcelo H.}",
year = "2006",
month = "7",
day = "1",
doi = "10.1016/j.coastaleng.2006.03.008",
language = "English (US)",
volume = "53",
pages = "781--792",
journal = "Coastal Engineering",
issn = "0378-3839",
publisher = "Elsevier",
number = "9",

}

TY - JOUR

T1 - Geometry and migration characteristics of bedforms under waves and currents. Part 2

T2 - Ripples superimposed on sandwaves

AU - Cataño-Lopera, Yovanni A.

AU - García, Marcelo H.

PY - 2006/7/1

Y1 - 2006/7/1

N2 - This paper presents results of a series of detailed measurements of geometric and migrating characteristics of ripples superimposed upon sandwaves under the action of combined waves and currents. Velocity measurements within the fluid, surface wave characteristics and 3D mapping of the bottom were recorded with an Acoustic Doppler Velocimeter (ADV), an acoustic water level sensor and a 32 composite element array of sub-aquatic acoustic sensors, respectively. Bottom records were statistically analyzed to obtain height, length and migration rates of ripples. Experiments examined ripple heights and wavelengths for the mobility factors (as defined in Eq. (4)) and the Reynolds wave number within the ranges 10 < ψ < 88 and 16 × 103 < Rew < 5 × 105, respectively. Measured values were compared with laboratory and field data together with semi-empirical and analytical formulae from the literature. Good correlation was obtained when plotting measured ripple length and length in dimensionless form as a function of the Reynolds wave number Rew. Under a given hydraulic condition, it was observed that ripples with different geometric characteristics may coexist at different locations over the sandwave. Ripple steepness is presented as a function of the Shields parameter although characterized with rather large scatter. Finally, average ripple migration speed is presented as a function of the Shields parameter and the mobility number.

AB - This paper presents results of a series of detailed measurements of geometric and migrating characteristics of ripples superimposed upon sandwaves under the action of combined waves and currents. Velocity measurements within the fluid, surface wave characteristics and 3D mapping of the bottom were recorded with an Acoustic Doppler Velocimeter (ADV), an acoustic water level sensor and a 32 composite element array of sub-aquatic acoustic sensors, respectively. Bottom records were statistically analyzed to obtain height, length and migration rates of ripples. Experiments examined ripple heights and wavelengths for the mobility factors (as defined in Eq. (4)) and the Reynolds wave number within the ranges 10 < ψ < 88 and 16 × 103 < Rew < 5 × 105, respectively. Measured values were compared with laboratory and field data together with semi-empirical and analytical formulae from the literature. Good correlation was obtained when plotting measured ripple length and length in dimensionless form as a function of the Reynolds wave number Rew. Under a given hydraulic condition, it was observed that ripples with different geometric characteristics may coexist at different locations over the sandwave. Ripple steepness is presented as a function of the Shields parameter although characterized with rather large scatter. Finally, average ripple migration speed is presented as a function of the Shields parameter and the mobility number.

KW - Bedforms

KW - Ripples

KW - Sediment transport

KW - Statistical analysis

KW - Waves plus currents

UR - http://www.scopus.com/inward/record.url?scp=33746237661&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=33746237661&partnerID=8YFLogxK

U2 - 10.1016/j.coastaleng.2006.03.008

DO - 10.1016/j.coastaleng.2006.03.008

M3 - Article

AN - SCOPUS:33746237661

VL - 53

SP - 781

EP - 792

JO - Coastal Engineering

JF - Coastal Engineering

SN - 0378-3839

IS - 9

ER -