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Li Z.,Dalian University of Technology | Li Z.,State Key Laboratory of Structural Analysis for Industrial Equipment | Sun L.,Dalian University of Technology | Sun L.,State Key Laboratory of Structural Analysis for Industrial Equipment | And 3 more authors.
Archive of Applied Mechanics | Year: 2013

The growth and collapse of gaseous bubbles near a movable or deformable body are investigated numerically using the boundary element method and fluid-solid coupling technique. The fluid is treated as inviscid, incompressible and the flow irrotational. The unsteady Bernoulli equation is applied on the bubble surface as one of the boundary conditions of the Laplace's equation for the potential. Good agreements between the numerical and experimental results demonstrate the robustness and accuracy of the present method. The translation and rotation of the rigid body due to the bubble evolution are captured by solving the six-degrees-of-freedom equations of motion for the rigid body. The fluid-solid coupling is achieved by matching the normal component of the velocity and the pressure at the fluid-solid interface. Compared to a fixed rigid body, the expansion of the bubble is not affected too much but much faster collapsing velocities during the collapsing phase of bubble can be observed when considering the motion of the rigid body. The rigid body is pushed away as the bubble grows and moved toward the bubble as the bubble collapses. The motion of two bubbles near a movable cylinder is also simulated. The large rotation of the cylinder and obvious deformation and distortion for the bubble in close proximity to a curved wall are observed in our codes. Finally, the growth and collapse of bubble near a deformable ellipsoid shell are also simulated using the combination of boundary element method (BEM) and finite element method (FEM) techniques. The oscillations of the ellipsoid shell can be observed during the growth and collapse of bubble, which much differs from the results obtained by only considering effects of a rigidly movable body on the bubble evolution. © 2013 Springer-Verlag Berlin Heidelberg.

Zhang J.,Qingdao Technological University | Zhang J.,State Key Laboratory of Coastal and Offshore Engineering | Zhuo H.,Qingdao Technological University | Jiang Z.,Qingdao Technological University
Tumu Gongcheng Xuebao/China Civil Engineering Journal | Year: 2012

Rocking-wall structure is new structural system in recent years, can reduce the seismic effect and structural damage, make it be used after earthquake with less repair or no repair. The new-typed ocean platform structure based on rocking-wall is put forward. Taking the JZ20-2 platform structure as example, the new structural system was analyzed under Tianjin wave and jam ice force by the finite element software ANSYS. The transient dynamic response includes displacement and acceleration response under different rocking wall stiffness. The analysis results show that the new-typed ocean platform has better control effect, the rocking wall stiffness has a great influence on displacement and acceleration response. When the stiffness takes a certain value, the control effect is very obvious to platform vibration.

Wang H.,Hebei United University | Zhang Y.,Tangshan City Drainage Co. | You Z.,Hebei United University | You Z.,State Key Laboratory of Coastal and Offshore Engineering
Asian Journal of Chemistry | Year: 2015

Micro-polluted water was treated by electrochemical oxidation method in this work. When the plate distance was 1 cm and electrolysis time was 10 min, NaCl solution was added to the reaction equipment, which made the ratios of concentration of NH4 + and Cl- were 1:1, 1:2 and 1:3, respectively. The removal effects on nitrogenous compounds of the change of the chloride concentration in the water by electrochemical method were investigated. The results revealed that the higher the chloride concentration in the water, the higher the removal rate to nitrogenous compounds, along with the increase of cell voltage, the removal rates of nitrogenous compounds increased too. Considering the power consumption per ton wastewater and other factors, the optimal running conditions of this experiment were the cell voltage 6 V and the ratio of concentration of NH4 + and Cl- were 1:3. © 2015, Chemical Publishing Co. All rights reserved.

Tang H.,Dalian University of Technology | Tang H.,State Key Laboratory of Coastal and Offshore Engineering | Song C.,Dalian University of Technology
Advanced Materials Research | Year: 2011

In the present work, the Cosserat micro-polar continuum theory is introduced into the FEM numerical model, which is used to simulate the strain localization phenomena under static and dynamic loading conditions. The numerical studies on progressive failure phenomena, which occur in a panel, characterized by strain localization due to strain softening and its development, are numerically modelled by two types of Cosserat continuum finite elements, i.e. u8ω8 and u8ω4 elements. It is indicated that both two Cosserat continuum finite elements possess better performance in simulation of strain localization. Because of the presence of an internal length scale in Cosserat continuum model a perfect convergence is found upon mesh refinement. A finite, constant width of the localization zone is computed under static as well as under transient loading conditions. © (2011) Trans Tech Publications, Switzerland.

Sang S.,Ocean University of China | Sang S.,Key Laboratory of Advanced Ship Design and Manufacture Technology | Sang S.,State Key Laboratory of Coastal and Offshore Engineering | Zhou Y.,Ocean University of China | Jiang X.,Ocean University of China
Applied Mechanics and Materials | Year: 2012

This paper used AQWA software to research the nonlinear motion characteristic of heave-pitch coupling of classical Spar platform in regular waves. With classic Spar platform as an example, the wave amplitude and periodic changes' effect to the nonlinear motion behavior of coupled heave-pitch is researched. After calculation, the critical periods corresponding to the different incident wave amplitude are obtained, based which, gets the instability parameter domain of coupling resonance of platform in the wave period-amplitude plane. The results in this paper show that the heave-pitch coupled resonance of platform depends on the wave amplitude and the ratio of the natural period of heave and pitch, and the incident wave period. © (2012) Trans Tech Publications, Switzerland.

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