Affiliations: School of Mechanical and Aerospace Engineering,
College of Engineering, Sunchon National University, Suncheon, Jeonnam 540-742,
Korea. E-mail: ksc@sunchon.ac.kr | Department of Mechanical Engineering, School of
Manufacturing Engineering, Seoul National University of Technology, Seoul
139-743, Korea
Abstract: The flow fields in a butterfly valve, consisting of a circular
cylinder and a circular plate with a circular shaft, are numerically
investigated with changing the valve angle, i.e., 15°,
45°, 75° and 90° (full-open). The
corresponding Reynolds numbers are chosen as 10^4, 4 × 10^4, 7
× 10^4, and 10^5. The pressure drops between the entrance and the
exit of the valve are 0.904, 0.575, 0.382 and 0.199, respectively at the above
four valve positions. The moment coefficients calculated for the valve shaft
are mostly due to the unbalanced pressure distribution on the both sides of the
valve plate and −0.365, −0.082, −0.033 and 0, respectively, for each valve
angle. The pressure distribution on the valve cylinder and the topological
streamline patterns qualitatively show the flow field exceedingly agitated by
the valve plate and its shaft.
Keywords: Butterfly valve, Blockage ratio, Pressure drop, Moment coefficient
