The demand for a centrifugal pump with open impellers for conveying dense fine particles in solid-liquid two-phase flow has increased significantly in actual engineering. The wear of dense fine particles on the centrifugal pump is also exceedingly prominent, which affects the engineering efficiency and economic benefits. The two-phase flow in the open centrifugal pump is three-dimensional and unsteady; the movement of high-volume concentration particles in the centrifugal pump and its mutual influence on the two-phase flow, which results in the calculation of wear, are very intricate. To study the wear characteristics of the centrifugal pump with open impeller with high-volume concentration particles more accurately, numerical simulation and experimental comparison are carried out for the impeller wear of dense fine particles transported by the centrifugal pump with open impellers. Considering the relationship between particles and walls, we used the Fluent 18.0 built-in rebound function and wear model. The RNG k- ε model and the DDPM model were adopted in the numerical simulation, and the numerical solution for centrifugal pump wear was performed under flow rate (9.6 m 3 ·h −1 , 12.8 m 3 ·h −1 , 16 m 3 ·h −1 , and 19.2 m 3 ·h −1 ), different particle sizes (0.048 mm, 0.106 mm, 0.15 mm, 0.27 mm, and 0.425 mm), and different particle volume concentrations (10%, 15%, 20%, 25%, and 30%), respectively. By comparing the serious wear positions of the impeller, the experimental results correspond well with the numerical simulation, which can be used to predict and study the wear characteristics of the impeller. The results show that the most serious area of blade wear is the middle part of the pressure surface, followed by the middle part of the upper part of the blade. The wear of the impeller is greatly affected by relevant parameters, such as pump flow rate, particle diameter, and particle volume concentration. These results can provide some basis for the wear-resistant design of dense fine particle impeller.

The nonlinear vibration behaviors of stiffened cylindrical shells under electromagnetic excitations, transverse excitations, and in-plane excitations are studied for the first time in this paper. Given the first-order shear deformation theory and Hamilton principle, the nonlinear partial differential governing equations of motion are derived with considering the von Karman geometric nonlinearity. By employing the Galerkin discretization procedure, the partial differential equations are diverted to a set of coupled nonlinear ordinary differential equations of motion. Based on the case of 1 : 2 internal resonance and principal resonance-1/2 subharmonic parametric resonance, the multiscale method of perturbation analysis is employed to precisely acquire the four-dimensional nonlinear averaged equations. From the resonant response analysis and nonlinear dynamic simulation, we discovered that the unstable regions of stiffened cylindrical shells can be narrowed by decreasing the external excitation or increasing the magnetic intensity, and their working frequency range can be expanded by reducing the in-plane excitation. Moreover, the different nonlinear dynamic responses of the stiffened cylindrical shell are acquired by controlling stiffener number, stiffener size, and aspect ratio. The presented approach in this paper can provide an efficient analytical framework for nonlinear dynamics theories of stiffened cylindrical shells and will shed light on complex structure design in vibration test engineering.

Sloshing is associated with the structural safety of liquid storage vessel. Installing the baffles inside the containers would be beneficial for the mitigating the damage due to the severe sloshing. In this study, an innovative type of double-side curved baffle was proposed to evaluate its effect on reducing sloshing in a rectangular tank under surge and pitch excitation. For comparison with conventional baffles, effects of the vertical baffle and the T-type baffle on mitigating sloshing were also studied experimentally and numerically by analyzing the free surface wave elevation as well as the hydrodynamic pressure on the tank wall. The effective stress at the double-side curved baffle along the height direction of the baffle is much smaller than that at the T-type baffle although they have the same mitigation effect on sloshing wave heights. The sloshing-induced effective stress on the double-side curved baffles was analyzed by varying their radian. Findings show that the effective stress on the baffle tends to decrease with the increase in the radian. The velocity field was presented to observe effect of the baffles on sloshing with the aid of ADINA and laboratory experiments conducted on a hexapod motion platform.