Numerical Simulation of Flow through a Laboratory Channel Gate using ANSYS Fluent

Abstract

Flow studies in control structures require the development of nonlinear differential equations that have no analytical solution but can be approximated by applying the finite volume method in mathematical models such as Fluent. This article presents a comparative analysis between a numerical model and a physical model of water flow in a laboratory channel using ANSYS Fluent. The scope of the study includes the development of a 2D model of the laboratory channel with a control section of a sliding flat rectangular gate and the mathematical development of the Navier-Stokes equations to model a biphasic flow of water and air throughout the computational domain, using appropriate boundary conditions. The methodology employed numerical simulation techniques using ANSYS Fluent, applying the finite volume method to solve the flow equations, and experimental techniques through direct measurements taken in the laboratory. The results demonstrate a 95.46% similarity between the mathematical modeling, direct measurements, and analytical calculations. Variables such as discharge coefficient, flow profiles, velocities at different points in the channel, and pressure distribution remained consistent throughout the computational domain. In conclusion, the advantages of the numerical model over the physical model are highlighted, emphasizing its efficiency and cost-effectiveness by allowing easy and simultaneous modifications in problem configurations, turbulence models, and boundary conditions. Additionally, the importance of the numerical model is highlighted by providing more accurate results than direct measurements made on the physical model, especially in turbulent areas and in the interaction of biphasic flow in the channel and gate. Finally, it is important to include a sensitivity analysis and mesh refinement in the mathematical model in such studies to avoid fluctuations near the gate where the section contracts.