Role of turbulence fluctuations on uncertainties of acoustic Doppler current profiler discharge measurements

This work presents a systematic analysis quantifying the role of the presence of turbulence fluctuations on uncertainties (random errors) of acoustic Doppler current profiler (ADCP) discharge measurements from moving platforms. Data sets of three-dimensional flow velocities with high temporal and sp...

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Detalhes bibliográficos
Autores: Tarrab, Leticia, Garcia Rodriguez, Carlos Marcelo, Cantero, Mariano Ignacio, Oberg, Kevin
Tipo de documento: artigo
Estado:Versão publicada
Data de publicação:2012
País:Argentina
Recursos:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositório:CONICET Digital (CONICET)
Idioma:inglês
OAI Identifier:oai:ri.conicet.gov.ar:11336/197913
Acesso em linha:http://hdl.handle.net/11336/197913
Access Level:Acceso aberto
Palavra-chave:WATER
TURBULENCE
ADCP
https://purl.org/becyt/ford/2.1
https://purl.org/becyt/ford/2
Descrição
Resumo:This work presents a systematic analysis quantifying the role of the presence of turbulence fluctuations on uncertainties (random errors) of acoustic Doppler current profiler (ADCP) discharge measurements from moving platforms. Data sets of three-dimensional flow velocities with high temporal and spatial resolution were generated from direct numerical simulation (DNS) of turbulent open channel flow. Dimensionless functions relating parameters quantifying the uncertainty in discharge measurements due to flow turbulence (relative variance and relative maximum random error) to sampling configuration were developed from the DNS simulations and then validated with field-scale discharge measurements. The validated functions were used to evaluate the role of the presence of flow turbulence fluctuations on uncertainties in ADCP discharge measurements. The results of this work indicate that random errors due to the flow turbulence are significant when: (a) a low number of transects is used for a discharge measurement, and (b) measurements are made in shallow rivers using high boat velocity (short time for the boat to cross a flow turbulence structure).