A CFD STUDY TO ANALYZE THE AERODYNAMIC TORQUE, LIFT, AND DRAG FORCES FOR A BUTTERFLY VALVE IN THE MID-STROKE POSITION

摘要

The ability to accurately predict the aerodynamic torque and lift and drag forces on a two-dimensional model of a 0.18 aspect ratio biconvex circular-arc disc operating in a compressible flow using Fluent 6.0 was investigated. Grid-convergence and time-convergence/stability were analyzed first, followed by a qualitative study of the Spalart-Allmaras, k-ε, and k-ω turbulence models with their enhancement features and model variants. Fluent was used to predict the pressure profile on the disc surface for disc positions 30°, 45°, and 60° (where 0° is the fully closed position), and over a range of pressure ratios. The pressure ratios were selected to determine the capability of Fluent to accurately predict the flow field and resulting torque in flows ranging from nearly incompressible to highly compressible. Fluent predictions for the pressure profiles on the disc were compared to test data so that the lift and drag forces and aerodynamic torque could be determined responsibly. Acceptable comparisons were noted.