| Valve is an important control element in pipeline system, whose function is connecting andcutting the flowing fluid. Due to the transient variation of valve degree in the opening orclosing process, it is easily to cause the production of swirl, secondary flow, cavitation andother complex flow conditions. The emergence and development of these complex flowconditions will lead to the operational failure of the valve. Thus, the main goal of this study isto investigate the transient flow characteristics of valve, and to provide theoretic support for thesecure operation of valve. The object of this study is set as ball valve, and the opening processis studied by experiments and numerical simulations. The impact of opening degree andopening speed on steady and transient internal flow characteristics are analyzed separately.Details are as follows:(1) The steady state and transient flow resistance experiments in different opening anddifferent opening speed was conducted, the steady flow resistance characteristics in differentopening and the flow and the pressure variation with time under different opening speed wereobtained. Then the results will be compared and analyzed.(2) The models were completed by the three-dimensional model software UG, and themodels were meshed by the Gambit. Based on the results, we use the Fluent to make the ballthree-dimensional numerical simulation of steady-state and transient under different openingspeed.(3) Analysis the effects of different opening and the opening speed of the ball inside thedifferent flow characteristics and flow resistance characteristics, then predictive the flowresistance characteristics performance. |
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