@article { author = {Azimi, R. and Kouchakzadeh, Salah and Bayat, E.}, title = {Variation of Manhole Minor Head Loss Coefficient in Sub-surface Drainage Network and its Influence on Water Surface Profile}, journal = {Journal of Hydraulics}, volume = {4}, number = {1}, pages = {41-51}, year = {2009}, publisher = {Iranian Hydraulic Association}, issn = {2345-4237}, eissn = {2645-8063}, doi = {10.30482/jhyd.2009.85512}, abstract = {Manholes are commonly used in subsurface drainage networks while the hydraulic characteristics ofthis structure for design purposes and for determining the discharge capacity of the network have notinvestigated yet. In this research a prototype scale experimental setup was prepared using drainagecorrugated pipes in order to determine the minor head loss coefficient of the manhole and toinvestigate its influence on the water surface profile. Data was gathered for a wide range of pipelongitudinal slopes and main pipe to lateral pipe discharge ratios. The data indicated that when thedischarge ratio tends to unity the head loss coefficient decreases to a constant value. AccordinglyI anaverage value was proposed for practical design purposes. The impact of applying such average valueon the water surface profile directly upstream of the manhole was investigated and reported herein.The results indicated that applying such average value predicts the water surface elevation within amaximum error of ±15%. Higher errors belong to lower discharge values which are not of practicalimportance. ThereforeI the application of proposed average head loss coefficient is recommended fordesign procedures.}, keywords = {}, title_fa = {تغییرات ضریب افت موضعی منهول در شبکه زهکش زیرزمینی و اثر آن بر نیمرخ جریان}, abstract_fa = {}, keywords_fa = {}, url = {https://jhyd.iha.ir/article_85512.html}, eprint = {https://jhyd.iha.ir/article_85512_a94d3e0324fe8781d32199bca4456973.pdf} }