Desenvolvimento de um simulador virtual de vazamento para testar correlacionadores acústicos comerciais

Detalhes bibliográficos
Ano de defesa: 2014
Autor(a) principal: Lima, Fábio Kroll de [UNESP]
Orientador(a): Não Informado pela instituição
Banca de defesa: Não Informado pela instituição
Tipo de documento: Dissertação
Tipo de acesso: Acesso aberto
Idioma: por
Instituição de defesa: Universidade Estadual Paulista (Unesp)
Programa de Pós-Graduação: Não Informado pela instituição
Departamento: Não Informado pela instituição
País: Não Informado pela instituição
Palavras-chave em Português:
Link de acesso: http://hdl.handle.net/11449/123716
http://www.athena.biblioteca.unesp.br/exlibris/bd/cathedra/21-05-2015/000830129.pdf
Resumo: Leak in pipes is one of the main concerns of water companies due to the scarcity and availability of potable water sources, especially in big cities. The cross-correlation technique has been used in the past 30 years to locate leaks in metallic pipes. Although the cross- correlation method works very well for metallic pipes, it does not have the same effectiveness in plastic pipes. This is mainly due to the high attenuation between the pipe wall and the fluid, which suppress rapidly the leak noise. Hence, leak noise does not travel long distance in such pipes. Moreover, the frequency range over which the leak energy is located, is at low frequency. Hence, the leak signal is easily affected by background noise. To avoid these problems, a band-pass filter is used to suppress undesirable noise before conducting the correlation. The selection of the band-pass filter limits is the key to have a reliable time delay estimate between two leak signals, which is used to calculate the position of a suspected leak. This work concerns the investigation and design of a leak simulator, here named Virtual Pipe Rig, using an analytical leak model together with mechanical actuators (shakers). The analytical model is responsible for generating leak signals used to drive the mechanical actuators, which are responsible for simulating the measure positions. This virtual pipe rig can be used to assess commercial correlators and training purposes. The main advantage of this method is the entire control of the experiment, so that the characteristic of the simulated leak signal is known beforehand