Applied Mechanics and Materials Vols. 687-691

Abstract: The pressed oil-extraction process is essentially a process of oil seepage through porous cake-shaped media. Permeability of seepage field changes along with the change of porous media caused by press pressure. The change of permeability affects fluid pressure and effective pressure of oil cake pores, which means that porosity is influenced. On the contrary, the change of porosity also has an impact on permeability. The interaction between the seepage and rheology fields is termed as fluid-solid coupling. If rheology of oil cakes is considered, the fluid-solid coupling seepage with the rheological properties is the essence of the pressed oil-extraction process. In the present study, we studied a permeability model based on the deformable and rheological properties of oilseed cakes and the effective stress. The seepage and rheology fields were analyzed by alternative application of the finite difference and finite element methods. The finite element calculation model of nonlinear rheology field was established by the time step-initial strain method. We used flax and cotton seeds as examples to perform numerical simulation and calculate the displacement and pore fluid pressure dissipation of flaxseed and cottonseed oil during the press process.

Abstract: This article probe into the depth of the flue gas heat recovery from the burning of natural gas. It explore the mechanism of the way to control the temperature of the flue gas from the burning of natural gas below the dew point temperature. It expounds the absorption way of sensible heat and latent heat from the vaporization in flue gas. After the study on the condensation heat transfer characteristics of the flue gas from the burning of natural gas, we can find that the dropwise condensation is more conducive to the heat exchange between flue gas and cooling water. And to find the method of dropwise condensation.

Abstract: Aiming at the random delays and packet dropouts in ZigBee network, a Generalized Predictive Control (GPC) algorithm is proposed. The control sequence combine with timestamp, feedback sequence and queuing mechanisms to design a predictive control strategy. The GPC algorithm derivation, system design and implementation method are given, and then the algorithm is validated in a networked control system simulation toolbox based on TrueTime. The proposed algorithm shows better performance than conventional PID algorithm for a DC servo motor in control system based on ZigBee technology.

Abstract: Six degrees of freedom in this paper, by using the ADAMS software to realize the industrial robots can make any saddle trajectory simulation, and trajectory parameters, and it is easy to control the generated trajectory of the saddle shape, size and spatial position,which will improve the efficiency of the industrial robot simulation. The method of complex space curve simulation is generic, and can test the coordinate axis displacement, so the executing agency for the actual factory to avoid movement interference has a certain significance.

Abstract: On the basis of analyzing anti-ship missile operational process, this paper expounds the factors set affecting the capture capability of anti-ship missile, systematically set up anti-ship missile capture capability evaluation model; By means of large-sample simulation experiment, this paper analyzes the effects of target designation accuracy on target speed capture probability. Simulation practice shows that the detailed simulation model establishment, large sample space design, and many times simulation experiments can realize missile searching probability simulation analysis under the condition of many factors interwoven impact, and can effectively support capture capability assessment under given conditions.

Abstract: A delayed predator-prey model with stage structure for predator and ratio dependent response function is considered. By calculating characteristic equations and analyzing characteristic roots, the sufficient conditions for local stability of all the equilibria and Hopf bifurcation are obtained. Moreover, We use an iteration technique and comparison arguments to derive the sufficient conditions of the global stability of the boundary and positive equilibrium.

Abstract: A dynamical system modeling method based on cell mapping is proposed in order to describe the system statistic property, and then a discrete optimal control table is constructed through each state cell excited by all input level recording the optimal cost value at the same time. Finally, a demonstration of the method is shown for the time optimal blast temperature set point control of a sintering machine.

Abstract: The reliability of the parallel mechanical leg (2ups+up) based on the repairable Markov model was studied. First the repairable Markov model was built up, and the matrix of the state transition rate was got. Then by solving the steady-state equation the steady state indexes such as the availability, the failure frequency, mean up-time, mean down-time, mean cycle time were obtained. Finally we gave the reliability and mean time to first failure by solving the differential equation group.

Abstract: The space debris of centimeter-size could pierce through the satellite shell and cause a first impact to the shell protection and a second impact to the internal structure. This paper focuses on the double hypervelocity impacts of the satellite propellant tank with baffle protection. The simplified 2D axisymmetric analysis model has been built and the double impact damaging effects were simulated based on the SPH algorithm. Three different speeds of the centimeter-size pill (10km/s, 7km/s and 5km/s) were selected and the simulation results turned out to be consistent with the empirical formula of the ground experiments, which proved the effectiveness of the simulation results. The average velocity changing curve showed that the residual energy of the fragment cloud decreased significantly after the second impact. As a result, the double-layer or multilayer protective structure is of great significance and should be prioritized for the satellite shell design.

Abstract: In this paper, different numerical methods on tidal current energy extraction of near-field and far-field hydrodynamic response are used to conduct simulation study. And the following aspects are used for simulation, including CFD model is used to establish three-dimensional numerical flume, layout plan of more tidal current energy electric generator with different spaces is designed, changes in near-field hydrodynamic are stimulated as well as the calculated results are compared and analyzed, in order to more clearly understand the influence of tidal current energy generator to the surrounding water flow, which has a certain guiding function for the optimization of tidal current energy generator group and protection for the marine environment and ecology.