EXPERIMENTAL INVESTIGATION ON DRAINAGE FUNCTION OF DRAIN PIPES CONNECTED TO MANHOLE

Abstract

Experimental investigation on hydraulics in pipe flows connected to manhole yields that a stable flow in manhole is significant for the improvement of drainage faculty. The connection with a drop between inlet and outlet pipes at manhole and the installation of a control plate in manhole were proposed. In this case, the connection angle between inflow and outlet pipes at manhole was adjusted as 120 degrees. Also, the slope of the outlet pipe was settled as about 1/5 (Model II). For the inlet horizontal pipe flow, the discharge coefficient for Model II-2(including control plate) could be increased from 0.62 to 0.73 in comparison with that for Model II-1. Further, if the connection angle is changed from 120 to 180 degrees (Model III), the flow passing the inlet pipe entered mainly to the outlet pipe at the manhole, and the discharge coefficient could be increased from 0.62 to 0.777.