The motion characteristics and numerical simulation method were developed to obtain input-output characteristics of a large-diameter butterfly valve. Under given operating conditions

velocity

pressure

torque and pressure drop were calculated to obtain the flow field of butterfly valve. Then

using some characteristic parameters such as velocity profile

pressure distribution

turbulence kinetic energy and turbulence intensity

the model of butterfly valve was established by fitting method and compared with experimental data. Results illustrated that flow field characteristic differed at different opening degrees

and when the opening degree was equal to or greater than 5365%

the flow velocity of the butterfly valve fluid at the inlet and outlet was relatively full

the flow performance was relatively good and the flow state was stable. The mathematical model of butterfly valve modified by the experimental data has high degree of confidence

making it feasible to analyze the motion characteristics of butterfly valve.