A review of acoustic measurement of small-scale sediment processes

Thorne, Peter D.; Hanes, Daniel M.

doi:10.1016/s0278-4343(01)00101-7

Cited by 385 publications

(395 citation statements)

References 69 publications

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“…Thus, the one-dimensional vertical profiles of suspended sediment concentration (backscatter) and mean particle sizes could be calculated from sediment cross-section scattering of the individual sound frequencies following the methodology of (and Thorne and Hanes (2002); Thosteson and Hanes (1998)), as presented in the MATSCAT toolkit (Buscombe, 2012 …”

Section: Experimental Setup and Wave Conditionsmentioning

confidence: 99%

Wave-induced coherent turbulence structures and sediment resuspension in the nearshore of a prototype-scale sandy barrier beach

Kassem

Thompson

Amos

et al. 2015

Continental Shelf Research

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Abstract:The suspension of sediments by oscillatory flows is a complex case of fluid-particle interaction. The aim of this study is to provide insight into the spatial (time) and scale (frequency) relationships between wave-generated boundary layer turbulence and eventdriven sediment transport beneath irregular shoaling and breaking waves in the nearshore of a prototype sandy barrier beach, using data collected through the Barrier Dynamics Experiment II (BARDEX II). Statistical, quadrant and spectral analyses reveal the anisotropic and intermittent nature of Reynolds' stresses (momentum exchange) in the wave boundary layer, in all three orthogonal planes of motion. The fractional contribution of coherent turbulence structures appears to be dictated by the structural form of eddies beneath plunging and spilling breakers, which in turn define the net sediment mobilisation towards or away from the barrier, and hence ensuing erosion and accretion trends. A standing transverse wave is also observed in the flume, contributing to the substantial skewness of spanwise turbulence. Observed low frequency suspensions are closely linked to the mean flow (wave) properties. Wavelet analysis reveals that the entrainment and maintenance of sediment in suspension through a cluster of bursting sequence is associated with the passage of intermittent slowly-evolving large structures, which can modulate the frequency of smaller motions. Outside the boundary layer, small scale, higher frequency turbulence drives the suspension. The extent to which these spatially varied perturbation clusters persist is associated with suspension events in the high frequency scales, decaying as the turbulent motion ceases to supply momentum, with an observed hysteresis effect. The suspension of sediment in turbulent flows is a complex case of fluid-particle interaction, governed by shear stresses (momentum exchanges) at the bed and within the benthic boundary layer (BBL). Defining the physical processes which dictate the resuspension of sediments in coastal and estuarine settings is fundamental for accurate predictions of bed morphology evolution (Van Rijn et al., 2007), and has profound implications for the biogeochemical processes that shape their local ecology (Thompson et al., 2011). It is also a prerequisite to quantifying erosion and deposition trends, and hence guiding engineering applications such as beach nourishment, defence schemes against erosion and flooding, maintenance of marine infrastructure and waterways, and aggregate dredging. There is a genuine need for better, robust models of suspended sediment transport in the coastal zone (Aagaard and Jensen, 2013). In a vision paper on future research needs in coastal dynamics, Van Rijn et al. (2013) highlighted the pressing need for research to support such models, focusing in particular on sand transport in the shoreface (non-breaking waves), surf and swash zones; employing field and controlled laboratory experiments.The mobilisation of sediments in the nearshore and shoreface is dominated b...

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Section: Experimental Setup and Wave Conditionsmentioning

confidence: 99%

Wave-induced coherent turbulence structures and sediment resuspension in the nearshore of a prototype-scale sandy barrier beach

Kassem

Thompson

Amos

et al. 2015

Continental Shelf Research

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“…Thorne and Hanes [16] presented details of ADV response on suspended sediments, and thus, details are not repeated here. Within the linear range, the responses for kaolinite and YRE sediment are close.…”

Section: Resultsmentioning

confidence: 99%

Comparisons of Different Instruments for Measuring Suspended Cohesive Sediment Concentrations

Shao

Maa

2017

Water

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Abstract:Laboratory experiments were conducted to compare the performances of four different instruments for measuring suspended cohesive sediment concentrations (SSCs). Among these instruments, two were different models of optical backscatter sensor (i.e., OBS3+ and OBS5+), one was an acoustic Doppler velocimeter (MicroADV), and the last was a laser infrared optical sensor developed at Hohai University, China (HHU-LIOS). Sediments collected from the Yangtze River Estuary and a commercially available kaolinite were selected to check the responses of these four instruments. They were placed in an aqueous solution, and the SSCs were changed within a range from about 10 mg/L to 30 g/L to demonstrate the effective measuring ranges for each instrument. For the kaolinite suspension, the results showed that the HHU-LIOS has a much larger linear response range (0.1 to 13 g/L) when compared with other devices (the MicroADV: 0.1 to 1.35 g/L; the OBS3+: 0.1 to 5 g/L; and the OBS5+: 0.1 to 1 g/L). For the sediment sample from the Yangtze River Estuary, the results showed that the HHU-LIOS has a much wider usable range (from 0.1 to 25 g/L), compared with those for the others. It also showed that a combination of using a HHU-LIOS for the quadratic increasing range up to 25 g/L and the OBS5+ for the clear decreasing output are able to measure the SSCs of the estuarine mud up to 50 g/L.

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“…In this section, one specific acoustic model based on backscattering and attenuation -that of Thorne and Hanes (2002) and Hurther et al (2011) -is outlined, since it is used as the basis of this study, and the reader is referred to a related paper (Rice et al, 2014) for a more thorough description. The received root-mean-square (RMS) voltage, V, excited in the ultrasonic transducers by backscattered energy is related to the mass concentration of suspended particles, M, and varies with distance from the transducer, r, as follows (Thorne and Hanes, 2002):…”

Section: Concentration Inversion Methods In Suspensions Of Solid Partmentioning

confidence: 99%

“…The third objective is to assess the suitability to general engineering applications of a model relating the acoustic backscatter signal received by an active emitter-receiver transducer to the physical and acoustic properties of suspended solid particles (Thorne and Hanes, 2002). The backscattering and attenuation coefficients that are required for implementation of the model have been measured previously only for quartz sand-type particles, i.e.…”

Section: Introductionmentioning

confidence: 99%

“…A number of concentration inversion methods exist (Hanes, 2012;Hanes et al, 1988;Lee and Hanes, 1995;Thorne and Hardcastle, 1997;Thosteson and Hanes, 1998) many of which were reviewed in detail by Thorne and Hanes (2002) and Thorne et al (2011). The issue of numerical instability is an important and well known one in both implicit and explicit inversion methods, as it can cause computed particle concentrations to deviate very significantly from the true values to an extent that increases with distance from the transducer(s).…”

Section: Introductionmentioning

confidence: 99%

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Measurement of particle concentration in horizontal, multiphase pipe flow using acoustic methods: Limiting concentration and the effect of attenuation

Rice¹,

Fairweather²,

Peakall

et al. 2015

Chemical Engineering Science

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Measurement of particle concentration in horizontal, multiphase pipe flow using acoustic methods: limiting concentration and the effect of attenuation AbstractAn acoustic dual-frequency concentration inversion method, in which the backscattered acoustic signal received by transducers operating in the megahertz range is used to determine the concentration profile in suspensions of solid particles in a carrier fluid and which was originally developed for environmental applications, is applied to arbitrary suspensions of general engineering interest. Two spherical glass and two non-spherical plastic particle types with a range of size distributions and densities are used. Particle concentration profiles in horizontal turbulent pipe flow at Reynolds numbers of 25 000 and 50 000 -below and above the critical deposition velocity, respectively -and nominal concentrations of 0.5, 1 and 3 % by volume are presented for the four particle species, using measured backscattering and attenuation coefficients. In particular, the effects of particle size, density and flow rate on the transport and settling behaviour of suspensions are elucidated. The results demonstrate the potential of this method for measuring the degree of segregation in real suspensions and slurries across a range of challenging application areas, such as the nuclear and minerals processing industries. The limitations of the method are explored in detail through an analysis of the acoustic penetration depth and the application-specific maximum measurable concentration, both of which can be used to determine the most appropriate acoustic frequencies and measurement Highlights Marine model for measuring suspended solid fraction adapted for general use. Glass and plastic particles tested at several fractions in horizontal pipe flow.  Clear differences observed between species and settling and non-settling flows. Limiting concentration and penetration depth derived to inform future experiments. Method has potential for use in several engineering applications.

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A review of acoustic measurement of small-scale sediment processes

Cited by 385 publications

References 69 publications

Wave-induced coherent turbulence structures and sediment resuspension in the nearshore of a prototype-scale sandy barrier beach

Wave-induced coherent turbulence structures and sediment resuspension in the nearshore of a prototype-scale sandy barrier beach

Comparisons of Different Instruments for Measuring Suspended Cohesive Sediment Concentrations

Measurement of particle concentration in horizontal, multiphase pipe flow using acoustic methods: Limiting concentration and the effect of attenuation

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