What are vortices and turbulence in butterfly valve hydrodynamic effects

The vortices and turbulence generated by butterfly valves during operation are two important phenomena in fluid dynamics. They directly affect the performance of the valve, the energy efficiency and vibration stability of the system.

Vortex

Causes:

Vortex refers to the rotating flow structure formed when the fluid flows through the butterfly valve. This vortex usually forms on both sides of the butterfly plate, forming one or more vortices. The formation of vortex is mainly affected by the flow field around the valve, especially when the butterfly plate is closed or partially closed.

Influencing factors:

Disc shape: Different shapes of discs will cause different forms of vortices. Typically, the edges and back of the butterfly plate are critical areas for vortex formation.

Flow speed: High-speed fluids are more likely to form vortices, so flow speed is a key factor in the generation of vortices.

Butterfly valve opening: When the valve is partially closed, it is usually easier for vortices to form. In the closed state, the formation of vortices may be more significant.

Impact and issues:

Energy loss: Eddy currents can cause local losses of energy, resulting in a decrease in system efficiency.

Vibration: The presence of eddy currents can cause vibrations in the system, negatively affecting the structure of valves and pipes.

Turbulence

Causes:

Turbulence refers to the chaotic, rotating and irregular flow state that occurs when fluid passes through a butterfly valve. Turbulence usually occurs when the flow rate is high, the valve is partially closed, or the disc surface has irregular geometric structures.

Influencing factors:

Flow speed: High-speed fluids are more likely to form turbulence. Turbulence usually occurs within a certain range of Reynolds numbers, which are directly related to flow velocity.

Disc Shape: Irregular geometry on the surface of the disc may contribute to the occurrence of turbulence.

Valve opening: A partially closed butterfly valve is more likely to cause turbulence.

Impact and issues:

Increased resistance: Turbulence increases the resistance of the system, causing pressure drop to increase and system efficiency to decrease.

Noise: Turbulence is often accompanied by noise, which can adversely affect the work environment.

Ways to reduce eddies and turbulence:

Optimize butterfly plate design:

The aerodynamically optimized butterfly plate design can reduce the interaction between the butterfly plate and the fluid and reduce the occurrence of vortices.

Control flow rate:

Reducing the flow rate of the fluid can reduce the generation of eddies and turbulence. This can be achieved by adjusting the opening of the valve or adding appropriate buffering devices to the system.

Smooth surface treatment:

Maintaining the smoothness of the butterfly plate surface and reducing the presence of irregular geometric structures helps reduce the occurrence of turbulence.

Optimize system design:

By optimizing the layout of pipes and valves and avoiding overly curved flow paths, you can help reduce the effects of turbulence.