Hydraulic performance of egg-section wastewater pipes under unsteady flow conditions

Pipelines can be used for various purposes and are used for the transport of oil, natural gas, generally liquid substances, oil, natural gas, liquid and gas transmission, and especially for the transport of drinking water and sewage. Pipelines produced in various materials operate in many sectors depending on the purpose of use. Waste-water pipelines are the facilities that collect the used water in the settlements, transfer it to appropriate treatment facilities, and discharge it from these facilities to suitable areas after primary and secondary treatment. In this study, the activities aimed at increasing the flow performance of eggsection pipelines in wastewater systems are discussed. In hydraulic performance evaluations, three different phases of flow, uniform or non-uniform flow conditions, analytical and numerical modeling were carried out. As a result of these models, the hydraulic performance of the wastewater pipelines was evaluated and the flow models based on different hydraulic calculations were compared. According to the results of the study, PVtop (total performance value) shows higher hydraulic performance than pressurized flows due to the high fluid velocity values in free surface flows. According to the sediment concentration R correlation calculations, the best hydraulic performance is Case 1, Case 2 and Case 3 are close to each other, and Case 4 has been seen to have lower performance. In this case, it was concluded that the R correlation performances of the pressure pipelines were low and high in the free surface pipe control sections. Due to the cross-sectional differences, different flow characteristics were determined in the pipe control volumes. It has been determined that the steel pipes show better hydraulic performance than concrete pipes, on high slopes, on flat sediment bases, and on wavy sediment bases, according to the passage time of fluids in different sizes of cross-sections. Keywords: Verification and Validation of STAR CCM+, Egg-Shape Wastewater Flow, Volume of Fluid, Hydraulic Performance of Wastewater Pipes, Unsteady Flow of Wastewaters