The interaction between fluid and a down-pumping pitched blade turbine fixed with a flexible shaft in the stirred vessel, as a typical fluid structure interaction phenomenon, was simulated by coupling the Computationa...The interaction between fluid and a down-pumping pitched blade turbine fixed with a flexible shaft in the stirred vessel, as a typical fluid structure interaction phenomenon, was simulated by coupling the Computational Fluid Dynamics and Computational Structural Dynamics. Based on the verification of the simulated impeller torque and dimensionless shaft bending moment with experimental result, the dimensionless shaft bending moment and various loads acting on impeller(including lateral force, axial force and bending moment) were discussed in detail. By separating and extracting the fluid and structural components from those loads, the results show that the shaft bending moment mainly results from the lateral force on impeller although the axial force on impeller is much larger. The impeller mass imbalance increases the shaft bending moment and the lateral force on impeller, but has little influence on the axial force and bending moment acting on impeller. The dominant frequencies of impeller forces are macro-frequency, speed frequency and blade passing frequency, and are associated with the impeller mass imbalance.展开更多
The pump is one of the most important energy consuming devices in an energy system. The axial force on a centrifugal pump is an important factor for improving the operation stability and the service life. Based on the...The pump is one of the most important energy consuming devices in an energy system. The axial force on a centrifugal pump is an important factor for improving the operation stability and the service life. Based on the Bernoulli’s equation, the formulas of the axial clearance are derived theoretically. The relationship between the impeller axial force, the clearance leakage flow rate and the axial clearance is obtained. The motion differential equation of the axial-auto-balanced impeller is established by the number axis modeling method. The asymptotic stability of the impeller is evaluated by the Lyapunov stability analysis. The transient simulation of the axial-auto-balanced impeller is carried out by the method of the computational fluid dynamics (CFD) with the dynamic mesh technology. The time required for the impeller to reach the stable state under different conditions is calculated. The effective values of the axial force are determined. This research is useful to improve the operation stability of the pump.展开更多
基金Supported by the National Natural Science Foundation of China (21376016).
文摘The interaction between fluid and a down-pumping pitched blade turbine fixed with a flexible shaft in the stirred vessel, as a typical fluid structure interaction phenomenon, was simulated by coupling the Computational Fluid Dynamics and Computational Structural Dynamics. Based on the verification of the simulated impeller torque and dimensionless shaft bending moment with experimental result, the dimensionless shaft bending moment and various loads acting on impeller(including lateral force, axial force and bending moment) were discussed in detail. By separating and extracting the fluid and structural components from those loads, the results show that the shaft bending moment mainly results from the lateral force on impeller although the axial force on impeller is much larger. The impeller mass imbalance increases the shaft bending moment and the lateral force on impeller, but has little influence on the axial force and bending moment acting on impeller. The dominant frequencies of impeller forces are macro-frequency, speed frequency and blade passing frequency, and are associated with the impeller mass imbalance.
基金the National Natural Science Foundation ofChina(Grant Nos.51909131,52079142 and 51836010)。
文摘The pump is one of the most important energy consuming devices in an energy system. The axial force on a centrifugal pump is an important factor for improving the operation stability and the service life. Based on the Bernoulli’s equation, the formulas of the axial clearance are derived theoretically. The relationship between the impeller axial force, the clearance leakage flow rate and the axial clearance is obtained. The motion differential equation of the axial-auto-balanced impeller is established by the number axis modeling method. The asymptotic stability of the impeller is evaluated by the Lyapunov stability analysis. The transient simulation of the axial-auto-balanced impeller is carried out by the method of the computational fluid dynamics (CFD) with the dynamic mesh technology. The time required for the impeller to reach the stable state under different conditions is calculated. The effective values of the axial force are determined. This research is useful to improve the operation stability of the pump.
