Experimental and numerical study on the quasi-periodic pulsation characteristics of cavitation flow in a control valve

Background: Cavitation poses a significant challenge for high-pressure drop control valves, as it can lead to considerable damage, including noise and vibration. The unsteady pulsation characteristics of cavitation flow, which are essential for comprehending flow-induced noise and vibration, remain inadequately understood. Methods: This study investigates the unsteady quasi-periodic pulsation characteristics of cavitation flow in a control valve through experimental visualization and numerical modeling using the Large Eddy Simulation (LES) model. Significant Findings: The results reveal that a key feature of throttling cavitation flow is the continuous shedding of hollow circular cavity structures in a quasi-periodic manner from the throttling section to the downstream region. A strong interaction exists between the evolution of the main vortex structures and the cavity structures. The unsteady characteristics of the flow parameters are significantly influenced by the quasi-periodic evolution of the large-scale cavity-vortex structure. The primary factor affecting the fluctuating characteristics of throttling cavitation flow is the quasi-periodic transfer of mechanical energy induced by the evolution of large-scale cavityvortex structures. Under more severe cavitation conditions, the unsteady pulsation characteristics of velocity and pressure become more pronounced.