Papers by Author: Wen Quan Wang

Abstract: The paper studies the linear vibrating mechanical behaviors of double-walled carbon nanotubes (DWCNTs) with the initial axial stress under the temperature field. The DWCNTs are modeled as double elastic shells coupled together through vdW interaction between inner and outer nanotubes. Based on the model, the relation between the amplitudes and the frequencies of the tubes is achieved. The results show that the initial axial stress could crucially affect the existence of the natural and intertube frequencies. Meanwhile, it is also concluded that the temperature change is significant for natural frequency, but weakly affects intertube frequency and amplitude ratios.

Abstract: Based on an elastic beam model, potential flow theory and N-mode Galerkin discretization technique, the dynamical stability behaviors of fluid-conveyed double-walled carbon nanotubes (DWCNTs) considering geometry nonlinearity relating to the time as variation of the flow velocity are studied. The results show that the bifurcations happen in turn of pitchfork and Hopf types as the flow velocity increases. The vdW forces do not change the bifurcation types but make the critical velocities increase sharply. Furthermore, the vdW forces play a critical role in keeping the synchronization of the time histories of the amplitudes or the velocities of different layers of the CNTs-fluid system.

Abstract: In order to understand the rationality of the structural design for one hydropower underground house, based on reasonable selection of loading method for generator pier, and appropriate dealing with volute casing and draft tube water pressure. Take a typical underground house of anlagensektion to build the three-dimensional finite element model, and spectrum method was applied to analyze underground powerhouse anti-seismic characteristic. The seismic response characteristic of powerhouse just under seismic action and static load of normal operation jointly are investigated. The anti-seismic safety property of powerhouse is evaluated. It provides scientific basis for powerhouse dynamic design and operation control that station project.

Abstract: In the present study, the dynamic Vreman model based on the global equilibrium between the subgrid-scale dissipation and the viscous dissipation with a global model coefficient are applied to large eddy simulation of turbulent flow in complex geometries. Distributions of pressure, velocity and vorticity as well as some flow structure are gained, which is helpful to examine the performance of SGS model and understand the flow characters in complex geometries.

Abstract: The paper studies the nonlinear vibrating mechanical behaviors of double-walled carbon nanotubes (DWCNTs) with the initial axial stress under the temperature field. The DWCNTs are modeled as double elastic shells coupled together through vdW interaction between inner and outer nanotubes. Based on the model, the relation between the amplitudes and the frequencies of the tubes is achieved. The results show that the initial axial stress could crucially affect the topological forms of the amplitude-frequency curve, whereas it is insensitive to the amplitude ratios in DWCNTs. Meanwhile, it is also concluded that the temperature change is significant for natural frequency, but weakly affects intertube frequency and amplitude ratios as well as amplitude-frequency curve.