Civil Engieering, Razi University
The efficiency and economical performance of sewer systems is an essential issue in urban drainage. The need for sewers to carry sediment has been recognized for many years. One of the main problems in designing sewerage systems is the sediment deposition. Sedimentation in sewers occurs regularly according to the alternating natural flow. The present study investigates the hydraulic characteristics of flow in channels with a circular cross section with different bed slope and their effects on sediment transport capacity by use of 3D numerical simulation of flow field with ANSYS-CFX software. It studies hydraulic features of the flow passing through a circular channel in a two or three phase conditions. Self-cleansing velocity and volumetric sediment concentration in various Froude numbers were compared by lab outcomes to validate the results of numerical model. Results of numerical simulation indicate a proper adaptation of numerical and experimental models. Longitudinal velocity counters obtained by numerical simulation are compared in two or three phase flows.