Objectives To address the operational instability, vibration, and abnormal noise issues in a specific steam turbine unit, this study proposes a method for modifying the internal flow characteristics of control valves through an internally-cut valve core structure.

Methods Initially, a full-scale high-precision modeling method was employed to establish the complete flow passage geometry of the control valve. Subsequently, two types of internally-cut valve cores were designed based on supersonic expansion suppression principles. A multi-scale hybrid mesh strategy incorporating various boundary layer types was implemented, with convergence acceleration achieved through multiple iterative computations.

Results Experimental validation demonstrated less than 5% discrepancy between test measurements and simulation results for key parameters across different valve core configurations, confirming the accuracy and reliability of the numerical methodology. The optimized steam flow characteristics in both the throttling region and the valve core bottom area of the novel design effectively mitigate energy losses and vibration noise caused by asymmetric flow patterns. Furthermore, the innovative structure reduces fluid dynamic forces on the valve core base by 20%-30%, significantly suppressing broadband flow-induced vibrations in both the control valve and turbine unit.

Conclusions The valve core configuration exerts substantial influence on flow field characteristics. The internally-cut valve core design proposed in this research provides valuable insights for optimizing flow field distribution, offering technical references for performance enhancement of similar steam turbine control systems.