It is highly desirable to improve the anti-slipping stability of the crimping structure for a reliable connection. This study innovatively presents a biomimetic strategy for designing a high-performance crimping structure for industrial hose assembly based on evidence that the special infundibulum dentis structure on the occlusal surface of ruminant molars has the potential of anti-slippage and can also reduce the risk of stress concentration. Utilizing reverse engineering technology, the three-dimensional (3D) digital model of the bovine molar was built as a representative prototype, and then corresponding characteristics of the infundibulum dentis were extracted with a fitting method for the bionic design of the crimping structure. Numerical simulations and experimental results both indicate that the bionic crimping structure has high resistance to slippage of hose body compared with the traditional type, and further, the formation mechanism of bionic anti-slipping performance was discussed.
A methodology of rotating vibration energy harvesting with nonlinear magnetic forces is studied in this paper. A mathematical model of rotating piezoelectric vibration energy harvesters with nonlinear magnetic forces is built by the Lagrange’s equation and assumed-modes method. The nonlinear model is solved by numerical methods. Then the effects of distance between two magnets are studied. The results demonstrate that the performance of rotating piezoelectric vibration energy harvester with nonlinear magnetic force is better than traditional linear ones when the distance between two magnets is appropriate.
Abstract In the present paper, an improved multiphase weakly compressible smoothed particle hydrodynamics model for balancing the accuracy and stability of the long‐term simulations is proposed to model the forced liquid sloshing in a tank. The governing equations of the multiphase flow are discretized by considering the density discontinuity over the interface. To suppress the pressure oscillation, a previous density correction term suitable only for single‐phase problems is modified and incorporated into the discrete continuity equation to suit multiphase problems. The modified density reinitialization algorithm is implemented to calculate the pressure of the boundary particles, and the coupled dynamic solid boundary treatment (SBT) is employed to determine the rigid wall condition. For convenience, a numerical probe algorithm is also proposed to accurately measure the wave height. The present model exhibits a better numerical stability than the previous multiphase smoothed particle hydrodynamics model, and its results well confirm with the experimental data of the forced sloshing of liquid excited by swaying or rolling.
This paper presented the numerical investigation reports about the performance of transonic wind tunnel's second throat.Firstly,second throats were designed according to the general design rule.Then exact Mach number control was studied by numerical simulation when different second throat areas were analyzed by adjusting wall flaps and center body.The numerical results indicate that the control precision of Mach number is 0.001.At last,different models were studied based on the numerical results,and then the most efficient model was selected.
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