In this paper, the sand break into highway problem in desert, which is caused by the sand flow blown by wind, is studied. The mathematical models are introduced by considering the fixed, semi-fixed and free sand desert fields based on the fluid dynamics and the sand particle dynamics. Different kinds of numerical models are made by changing the desert highway height, wind flow direction and its uniformity. The weak coupling method is used due to spatial relationships between air flow field and the sand flow field. Finally, by coupling the airflow field and sand flow field with desert highway, the numerical simulations of sand forming process on desert highway are conducted. The numerical results shown, that the wind blown sand breaks into highway easier when wind direction perpendicular highway and if the highway height higher than the range size of the sand surface the wind blown sand break into highway is more difficult.

In this study, to conduct numerical simulation of desert physiognomy forming process in fixed, semi-fixed and free sand desert field by considering the sand flow process by wind, the numerical model based on the hydrodynamics and sand grains kinemics are proposed. For analyze the actual characteristic of sand movement phenomenon, the stream flow field and desert flow field are introduced and mathematical model for numerical analysis are established by considering the sand shape, size and mass in order to describe the fixed, semi-fixed and fully free sand desert physiographical process. Then according to the real fixed, semi-fixed and free sand flow field by coupling with stream flow field, several models are made and numerical simulations are conducted.

Meshing for finite element analysis accuracy plays a very important part in numerical simulation of Periodic Symmetric Struts Support (PSSS). Different accuracy can be obtained by different element sizes or types. Three element types and eight element sizes are used for comparing the accuracy of modal analysis in this paper. Comparing with the mutual relations of different accuracy, the scientific basis is provided for selecting the correct mesh size and improves the efficiency of numerical calculation in modal analysis.

In this paper, the Turing reaction-diffusion model coupled with Finite Element Method (FEM) is implemented first by considering the biomechanical model iBone (Imitation Bone). Then the shape optimization of Metal Welded Bellows Seal (MWBS) is conducted based on the biomechanical bone forming process by considering the osteoclasts and osteoblasts process. The MWBS mass and shape is changed by changing the initial boundary condition, then some reasonable results are obtained by keeping the required forming value, and the new S type wave of metal welded bellow of mechanical seal are obtained. Finally, the strength evaluations are conducted for new optimized S type model and original V and S type models by using the FEM software.

Wind caused the much sediment fluxes leading to both erosion and deposits in the sandy desertification area, and the much kind of beautiful sandy desert morphologies are formed. This is really crucial to the development of the dynamic behaviour of aeolian transport of sand particles. The sand desert morphologies are representing significant information archives for understanding the desertification problem. Dynamics and numerical modeling provides an essential tool for studying the aeolian transport of sand particle and morphology of sand desert such as ripple and dune. In this study, the mathematical models based on the dynamics are analyzed by considering the several keys as saltation, creep, suspension, avalanche and its threshold condition etc. for sand morphology forming processes. Then due to sand flow field real characteristics, the establishing process of stream flow field are analyzed, and the implication relationships as well as the coupling process between uniform stream flow field and the sand flow field are analyzed. Finally, the sand flow field models is discretized, and different kinds of sandy desert morphology are simulated by considering the sand particle size and mass in fixed, semi-fixed and free sand flow field area.

This article presents the gear modeling method in dynamic mechanical analysis using SPH (Smoothed Particle Hydrodynamics) analysis method. The parameter equations of the transition curve of gear root and the other parts of gear are decided. The 3D discrete particles model is established based on the parameter equations. The SPH pre-process program of global and local dividing is developed. The error between the divided discrete particles and theoretical profiles of the gear has been analyzed. The analysis results show that this modeling method is a relatively better method and the correct SPH discrete particles can be divided by this method.

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In this study, the stiffness and the flexibility of welded metal bellows of mechanical seal is studied numerically by changing the number of bellows membrane and the loading condition. The relationship between the number of membrane and the displacement, the stress and the flexibility are analyzed. For further improved the axial displacement, overall stiffness and the flexibility of the welded metal bellows membrane, the finite element analysis are conducted. The numerical results show that the maximum stress keeps constant value with increasing the number of bellows membrane under the same loading condition. The relationship between number of bellows membrane and stiffness as will as the flexibility are obtained. It is shown, stiffness is decreased and flexibility is increased with increasing of the number of the bellows membrane.