Modelo para determinação da perda de carga contínua em tubos elásticos / Model for determining the continuous head losses in elastic pipe
AUTOR(ES)
Osvaldo Rettore Neto
FONTE
IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia
DATA DE PUBLICAÇÃO
05/08/2011
RESUMO
Total head losses are accounted in the irrigation hydraulic projects, that would be the continuous losses and the local head losses, aiming to maximize the uniformity of water distribution, characterizing an adequate pump set to the irrigation system e thus, minimizing the project implantation and annual costs. With informatics support, complex calculation problems are solved with ease, therefore it is possible to apply more complex models for head loss calculation in the irrigation system, resulting in values closer to the reality, with greater details. The head loss represents the water energy dissipation as heat, along the piping, due to the resistance to the flow offered by the fluid viscosity and by the particles inertia. It is variable according to the size of the rugosities of the pipe wall, piping diameter and the water velocity. plastic industry and its derivates, with engineering support, have improved the quality of the materials for the pipe manufacturing, mainly polyethylene. The usage of plastic material pipes for irrigation, of lowest cost, has risen in the latest years. The flexibility of these pipes leads to the internal diameter increase with pressure increase, fact already observed in research and that are not taken into account by mathematics equating used to determine the head loss. This paper proposes a model where it takes into account the elastic module (E) of the pipe to determine the diameter alteration in elastic pipes due to the pressure, affecting the determination of continuous head loss. Elastic Module proposed associated to Universal Equation, showed average performance rate of 0,9% being considered a extremely good estimative of reality.
ASSUNTO(S)
diameter variation elastic pipe elasticidade das estruturas elasticity modulus. head losses irrigação modelos matemáticos perda de carga tubos flexíveis.
Documentos Relacionados
- Quantificação do erro na determinação da perda contínua de carga em tubos elásticos
- Perda localizada de carga em gotejadores integrados em tubos de polietileno
- Metodologia para determinação da perda de carga localizada em emissores não coaxiais integrados a tubos de polietileno
- Perda localizada de carga em conectores utilizados em microirrigação
- Índice geométrico na determinação da perda de carga localizada em conexão de emissores sobre tubos de polietileno de pequenos diâmetros