Question

A circular storm water sewer 1.5 m in diameter and effective roughness size 0.6 mm is laid to a slope of 1:500. Determine the maximum discharge which the sewer will convey under uniform open channel conditions. If a steady inflow from the surface runoff exceeds the maximum open channel capacity by 20%, show that the sewer will become pressurized and calculate the hydraulic gradient necessary to convey the new flow. (ans. 3.6 m3/s and 0.00324) without using the mannings formula (solve it without mannings)

Answer 1