Determinação do limite de aplicação entre os métodos dinâmico e estacionário em medições de vazão utilizando ADCP

• Ano de defesa: 2016
• Autor(a) principal: Breno Guerreiro da Motta
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal de Minas Gerais; UFMG
• Palavras-chave em Português: meio Ambiente e recursos hídricos; Saneamento; Recursos hídricos Desenvolvimento; Engenharia sanitária; Processo estacionário
• Link de acesso: http://hdl.handle.net/1843/BUBD-AAFEBD

Rivers flow measurements are currently done by the use of equipments like current meters or acoustic, such as the Acoustic Doppler Current Profilers - ADCP, which are gradually replacing the current meters due to their ease of use, less measurement time and having no moving parts. Measurements can be performed by the dynamic method, being the most usual for ADCP, in which they are moved from one river bank to the another, continuous collecting speed data and areas, or the stationary method, in which the river is divided into vertical and flow measurement takes place collecting speed data at these and, using correlations with subareas of the cross section, the flow is calculated. This study aimed to compare flow measurements performed with the two different dataacquiring methods with ADCP, comparing the results with measurements with current meters, in order to determine physical and hydraulic conditions of measurement sites that allow you to select the most appropriate method. Additionally, this work also contains an assessment of the necessary time span for acquiring data at each vertical so that an average speed is properly obtained. An Sonteks M9 ADCP were used initially in 14 flow measurement sites for determining the time span for acquiring data in each vertical and, after, in 25 sites in which the flow measurements were made with both ADCP methods and a Gurley Price current meter. It is noteworthy that the stations were selected in order to present a heterogeneous sample of physical and hydraulic conditions, with speeds ranging from 0,06m/s to 0,69m/sand average depths from 0,60m to 2,68m. The results indicated that the flow measurements performed with any method presented a maximum difference of 4,80% between themselves and the variations were well distributed between positive and negative, being associated with random errors. It was not possible to determine flow speed or other physical conditions that indicate the selection of a particular method.