Influence of visco-elasticity on pressure wave velocity in polyethylene MDPE pipe

• Autorzy: Mitosek M. , Chorzelski M.
• Języki publikacji: EN

Abstrakty

EN

Many of the pipe materials, like polyethylene (MDPE, HDPE) or polypro-pylene (PP), turn out to be visco-elastic. The materials in particular, prove to have strongly time-dependent strain properties. As the propa-gation velocity of pressure waves primarily depends on the fluid bulk modulus and the elasticity of the pipe wall, the above material property has considered the influence in unsteady pipe flow (e.g. in water ham-mer). The pressure velocity in visco-elastic pipes depends on the pres-sure oscillation frequency. The applicability of the method of MOC char-acteristics is limited in the sense that purely elastic strain behaviour has to be assumed. In order to take into account the special properties of visco-elastic pipes, the parameters of the Kelvin-Voigt elements, as well as a complex Young's modulus (dynamic modulus of elasticity) are used to described the pressure velocity. The use of the complex wave velocity seems to be especially useful. However, the velocity should be meas-ured during unsteady water flow. The experiments carried out show that pressure disturbance velocity in MDPE pipe strongly depends on the length of the pipe-line. The velocity increases noticeably when the length of the pipe decreases.

Słowa kluczowe

EN

water hammer; pressure wave velocity; viscoelasticity; polyethylene MDPE pipe

• Wydawca: Institute of Hydro-Engineering of Polish Academy of Sciences
• Czasopismo: Archives of Hydro-Engineering and Environmental Mechanics
• Rocznik: 2003
• Tom: Vol. 50, nr 2
• Strony: 127--140
• Opis fizyczny: Bibliogr. 20 poz., il.

Twórcy

autor

Mitosek M.

• Warsaw University of Technology, Institute of Water Supply and Water Engineering, Nowowiejska 20, 00--653 Warsaw, Poland

autor

Chorzelski M.

• Warsaw University of Technology, Institute of Water Supply and Water Engineering, Nowowiejska 20, 00--653 Warsaw, Poland

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