FORMULA ON ENERGY LOSSES AT TWO-WAY CIRCULAR DROP MANHOLE

• Published in: Doboku Gakkai Ronbunshuu G Vol. 62; no. 1; pp. 162 - 170
• Main Authors: ARAO, Shinji, KUSUDA, Tetsuya
• Format: Journal Article
• Language: Japanese
• Published: Japan Society of Civil Engineers 2006
• Subjects: drop manhole; formula; head loss; urban drainage
• ISSN: 1880-6082
• DOI: 10.2208/jscejg.62.162

Several flood-analysis models have been already developed in construction consulting companies, universities and public research organizations. Some flood-analysis models, such as MOUSE, Info Works and SWMM have been generally used by Japanese construction consulting companies. Each formula describing the energy loss at the manhole in a storm sewer is, however, different from each software application, and consequently the results of simulation of prediction on inundation, flood area and water depth on the ground surface in urban areas are also different. A more exact estimation of the energy loss at a manhole is necessaly in flood analysis. This paper proposes a new formula for energy loss coefficients that considers structural and hydraulic elements, such as manhole size, pipe size, drop between upstream and downstream pipes, connecting angle of pipes, and water depth for a two-way circular drop manhole. In the proposed formula, calculated values of energy loss at the manhole are within an error of ±30% of the measured values in accuracy except some structural conditions for the manhole and connecting pipes.