ENERGY LOSS CHARACTERISTIC OF FOUR-WAY CIRCULAR MANHOLES AT CROSSROADS

Abstract

 The authors have formalized the energy loss coefficient for two-way and three-way circular manholes where one or two inlet pipes are connected to an outlet pipe. However, there are many variables to consider in a four-way circular manhole at a crossroad, which makes formulation difficult. Therefore, the authors first formulated a model for a four-way circular manhole under the condition that the flow rates of two opposed lateral inflow pipes were the same. In this paper, we clarified energy loss characteristics of a four-way circular manhole by changing the planar arrangement of three inflow pipes with different pipe diameters, and further varying inflow rates to the three inflow pipes. When the flow rate in the straight pipe was small, the energy loss coefficient for the lateral inflow pipes changed more than that for the straight pipe with the change of lateral flow rates.