EQUIVALENT ROUGHNESS OF PRESSURE AND PRESSURE-FREE CONDUITS
Pages 181-187
In the article, the coauthors have proven that equivalent roughness k is preferable to Manning-Pavlovsky roughness n due to its capability to describe the friction loss more accurately.Here, the authors make an attempt to analyze relationship between equivalent roughness k and Manning-Pavlovsky roughness n . The authors have proven that in the event of unavailability of exact choice of n, substantial errors in the value of equivalent roughness are possible. Experimental identification of the equivalent roughness value must meet specific requirements, including the flow uniformity within the tested section of the water supply network and the need to identify the equivalent roughness value within the area of square resistance. Besides, the authors have proven that Nikuradse’s and Zegzhda’s formulas are only applicable in specific experimental testing conditions pre-set by the above researchers, and they cannot be used in other cases.
DOI: 10.22227/1997-0935.2013.4.181-187
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