Değişken Enkesitli Açık Kanal Akımının Deneysel ve Sayısal Modellemesi

Abstract

In this study, the open channel flow, interacts with the trapezoidal structure which forms constitutes the narrowing and expansion in the open channel is investigated experimentally and numerically. In experimental studies, velocity field and free surface profile are measured with acoustic doppler velocimeter (ADV) and limnimeter, respectively. Standard k-ε, Renormalization Group k-ε, Realizable k-ε, Standard k-ω, Shear Stress Transport, Reynolds Stress Model, Detached Eddy Simulation and Large Eddy Simulation models are used to determine the velocity field and free surface profile.. Figure A. Three-dimensional computational grid Purpose: Fluid-structure interaction problems and multiphysics problems in general are often too complex to solve analytically and so they have to be analyzed by means of experiments or numerical simulation In this study, the flow that interacts with the trapezoidal head structure, which constitutes the narrowing and expansion section in the open channel, has been investigated experimentally and numerically. Theory and Methods: In experimental studies, the velocity field and flow profiles are measured using Acoustic Doppler Velocimeter (ADV) and limnimeter, respectively. In numerical modeling, different turbulence closure models have been tested for their success in estimating the velocity field and free surface profile. In the evaluation of the model performance to predict experimental results, Mean Square Error (MSE) and Mean Absolute Relative Error (MARE) parameters are used. Grid Convergence Index (GCI) method is used to determine the mesh density and the Volume of Fluids (VOF) method is used to determine the free surface profile. Results: As a result of the study, it is determined that DES model is more successful than used other models in determining velocity field and flow profile according to MSE and MARE. Conclusion: The size of the region where the negative velocity value formed after the contraction zone of the horizontal velocity component (u) value decreases as it moves from the bottom of the channel towards the surface. It was observed that the density of the numerical velocity vectors increased as it progressed from the bottom of the channel towards the free surface. In addition, it is seen from the results obtained that numerical calculation methods can be used successfully in solving such flow problems.