Investigation of a novel ball valve design for enhanced flow control using computational fluid dynamics
Abstract
Computational Fluid Dynamics (CFD), a branch of fluid mechanics, uses numerical analysis and mathematical algorithms to simulate fluid flow, including the chaotic and unpredictable behavior within a valve; with a high degree of accuracy, provided the computational setup is well-constructed and validated against experimental data.
In this thesis, a Computational Fluid Dynamics analysis is performed, which study a novel ball valve design with enhanced flow control capabilities. The simulations are conducted using OpenFOAM v2206, and the governing equations were coupled using Reynolds Averaged Navier-Stokes (RANS) equations, which is used to simulate the turbulent flow; For the turbulence model the k-omega Shear Stress Transport (SST) model was chosen, as it is able to capture the flow separation within the valve. Since there is no experimental data available for the novel ball valve design, the computational setup was verified by running the simulations using a standard ball valve geometry, and the results are compared with available data and previous studies.
Once the computational setup provided satisfactory results, further simulations were conducted which contained the geometry for the new control ball valve design. The control ball valve did produced flow coefficients which showed enhanced flow control capabilities, but not as fine of a control that might have been expected. Indicated by velocity contour plots, the valve will have increased erosion on the seat ring downstream of the valve if the valve is used at a opening $\alpha$ angle of less than 60 degrees. Turbulence kinetic energy plots also showed that the flowing fluid will experience a greater mixing and energy loss, when compared with a standard ball valve. Pressure contour plots of the valve also indicated that there are high pressure gradients occurring throughout the control ball valve.