Browsing by Author "Demir, Vedat"

Now showing 1 - 2 of 2
  • No Thumbnail Available
    Item
    Determination of the Hydraulic Properties of a Flat Type Drip Emitter using Computational Fluid Dynamics
    (Ankara Üniversitesi, 2020-06-04) Demir, Vedat; Yürdem, Hüseyin; Yazgı, Arzu; Günhan, Tuncay; Ziraat Fakültesi
    The objective of this study was to determine the hydraulic properties of a flat type emitter using Computational Fluid Dynamics with different turbulence models and model options. In addition, it is aimed to investigate the effects of the emitter hydraulic properties on the design when the same emitter is used in drip irrigation pipes with different wall thicknesses. The lowest mean percentage deviation between the measured flow rates and the calculated flow rates with turbulence models was found as 0.70% and 0.74% in the SST k- and Stress-Omega RSM turbulence model for the wall thickness of 0.25 mm pipe, respectively. Also, the mean percentage deviation for the laminar turbulence model was found to be -1.01%. The minimum MAE (0.021 L h-1) and RMSE (0.028 L h-1) values were found in the SST k- low-Re corr. turbulence model and the minimum MAPE (1.068%) was found in the laminar turbulence model.
  • No Thumbnail Available
    Item
    Measurement and Prediction of Total Friction Losses in Drip Irrigation Laterals with Cylindrical Integrated in-line Drip Emitters using CFD Analysis Method
    (Ankara Üniversitesi, 2019-10-05) Demir, Vedat; Yürdem, Hüseyin; Yazgı, Arzu; Günhan, Tuncay; Ziraat Fakültesi
    The objective of this study was to predict total friction losses in drip irrigation laterals with cylindrical integrated inline emitters at different spacing using Computational Fluid Dynamics (CFD) simulation method. Two types of drip irrigation laterals with different technical specifications were used in the study. In the laboratory, the total friction losses were measured in the laterals for different velocities. In CFD analysis, standard k-ε, RNG k-ε, realizable k-ε, Reynolds Stress (RSM) with Linear Pressure-Strain (LPS) turbulence models and standard wall function, non-equilibrium wall function, enhanced wall treatment were considered. CFD simulation results were compared with experimental total friction losses in laterals. The highest prediction was obtained by RSM turbulence model with LPS using standard wall function with the lowest values of MAPE (2.96%) and RMSE (369 Pa).