IAHR, founded in 1935, is a worldwide independent member-based organisation of engineers and water specialists working in fields related to the hydro-environmental sciences and their practical application. Activities range from river and maritime hydraulics to water resources development and eco-hydraulics, through to ice engineering, hydroinformatics, and hydraulic machinery.
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You are here : eLibrary : IAHR World Congress Proceedings : 36th Congress - The Hague (2015) ALL CONTENT : Water engineering : Wave-blockage interaction in pipes
Wave-blockage interaction in pipes
Partial blockages are common in engineered as well as natural pressurized conduit systems that transport liquids.
Blockages in water supply systems often result in wastage of energy and financial resources, reduction in carrying capacity, increased potential for contamination. Transient-based defect detection methods (TBDDM) are highly promising because they are long range, non-intrusive, efficient and cost-effective. There are a number of past researches that focus on developing techniques and algorithm that use TBDDM to detect blockages, but there is little focus on understanding the physics of wave-blockage interaction. This paper analytically investigates the wave-blockage interaction for a single and multiple blockages with varying length scales. A harmonic wave with wavelength λ is injected into an unbounded pipe of area A containing N blockages. Each blockage is modeled as a pipe segment of length li and area Ai, where i=1,2,N. The theoretical results are corroborated with the numerical results. As expected, λ and the
intact pipe diameter are found to be the natural length scales in the longitudinal and radial direction, respectively. For blockages with small radial extent (i.e., Ai/A ~ 1), strong interaction between the injected wave and all blockages only occurs if the probing wavelength is such that the minimum li / λ>>1/40. Any probing wave and blockage whose length scales do not satisfy this criteria do not interact (i.e., a wave passes through without interaction with any blockage whose length is significantly smaller than λ). For blockages with Ai / A<<1, strong interaction between the injected wave and all blockages occurs provided that minimum (li / λ)(A/Ai) is of order 1.
File Size : 426,017 bytes
File Type : Adobe Acrobat Document
Chapter : IAHR World Congress Proceedings
Category : 36th Congress - The Hague (2015) ALL CONTENT
Article : Water engineering
Date Published : 30/09/2015
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