Numerical modeling of hydrodynamic vibrations in the flow passage of centrifugal pumps

The numerical modeling method enables researchers to study hydrodynamic processes through pump flow passage testing which serves as evidence to support modifications in existing centrifugal pump design methods. Hydrodynamic vibration critically impacts centrifugal pump reliability and performance under off-design conditions. This study presents a numerical model coupling rotor dynamics with hydraulic characteristics to analyze vibration's effect on flow rate and head. The approach integrates mechanical motion equations with vibration-dependent hydraulic loss models and harmonic-response solutions. We propose a physical mechanism where vibration arises from transit-inertial flow interactions in impeller passages, periodically disturbed by the volute tongue. The model predicts predominant vibration at blade-passing frequency, strongest transversely. Validation used vibration data from NM-type oil pipeline pumps at reduced flow. Results show flow rate departures increase hydrodynamic instability, elevating vibration and reducing hydraulic performance. This model enables vibration diagnostics and pump design optimization.