Advanced Materials Research Vols. 482-484

Abstract: This paper mainly introduced the GPRS wireless data transmission technology constitutes a new type of gas monitoring system, which is suitable for modern intelligent residential family user gas monitoring, the gas leakage and abnormal gas monitoring and alarm control, but also for the gas company to provide reading, saving a lot of manpower, material and financial resources.

Abstract: In this paper, a numerical two-phase flow model combining with the Realizable k–ε turbulent model for compressible viscous fluid is presented for the computation of flow characteristics in an aeration tank; and the equations are solved with the finite volume method. The free fluid surface is simulated by the VOF method. A multigrid technique based on the full approximation storage (FAS) scheme is employed to accelerate the numerical convergence. The numerical results for velocity and turbulent kinetic energy distribution in the aeration tank are obtained. It is shown that the Computational Fluid Dynamics (CFD) is a valuable tool to analyze the interaction of flow field and aeration.

Abstract: Based on the aging of Chinese society and the analysis of physiological characteristics of the elderly, home nursing beds for the elderly status of the product research, analysis of product design shortcomings, from the ergonomic point of view of functionality, parameters, modeling, etc. study, and gives the elderly home nursing bed design.

Abstract: Embarked from the ductility theory, the bending moment amplitude modulation limiting value ductility expression which satisfies the bearing capacity requirements have been deduced，on the value of the bending moment amplitude modulation coefficient, the influence of the using stage crack width limiting value has been considered, and the suggesting formula of the bending moment amplitude modulation coefficient has been proposed. With the aid of APDL language in the ANSYS, the entire process force analysis to statically indeterminate prestressed concrete beam has been carried on, the finite element computed result and the experiment result has been confirmed, through the example drew correlation curve, confirmed with the experiment, the beam's ultimate bearing capacity has been discussed, and the plastic hinge's formation and the influence of moment redistribution to the ultimate bearing capacity has been analyzed.

Abstract: Aiming at the structural feature of starting water separator, a 3-D finite element model of temperature field is proposed. The starting water separator of a Ultra Supercritical Boiler(USB) has been numerically simulated by using of finite element soft ware Ansys. The boundary condition of the separator is determined. All of the working conditions are simulated. The results have the same distribution laws with the monitoring data of power plant. The maximum temperature difference between out wall and inner wall occurs in the temperature-rise period during the cold start-up, but the value between top wall and bottom wall is very lower. The simulation results can not only provide a basis for the thermal stress analysis and the life loss calculation but also provide rationalization proposal for the plant safe operation.

Abstract: The minimum fluidization behavior of four different binary particle systems with different Geldart classification is experimentally investigated by carrying out slow defluidization of an experimental cold device of I.D. 300 mm and height 3 m. The solid particles are four kinds of quartz sand particles with equal density, corresponding to Group A, B, C and D particles of Geldart classification, respectively. The fluidization processes can be divided into packing state, partial fluidization state and complete fluidization state. The difference in physical properties and mass fraction of the two constituent solid phases is found to strongly influence the fluidization behavior and the minimum fluidization velocity during the slow defluidization process. For binary particle systems, the minimum fluidization velocity decreases with increasing mass fraction of the component whose fluidization quality is better. Finally, the models of Noda et al. (1986), Cheung et al. (1974) and Chiba et al. (1979) are used to predict the minimum fluidization velocity of above binary particle systems.

Abstract: Packing pressure directly influences quality of the plastic part. It is an important stage of plastic injection molding. This paper introduces the packing process.CAE software Moldflow provided the possibility to simulate the flow process of the plastic air intake manifold at different pressure and to predict the position of air traps. Packing pressure is determined by comparing analysis results and avoided mold adjustment and mold repairing. Analytic result shows that packing pressure at 70MPa can make the maximum injection pressure, melt flow rate, the required maximum clamp force smaller. And at that time, The air traps situation is also better. Practice proves that it is perfect of the finished sample of the plastic air intake manifold on basis of simulation.

Abstract: Due to the tube is suffering deformation and damage by a series of factors, such as external force, chemical corrosion etc. The production of oil and the oil wells' service life is directly affected. As the number of casing damage is increasing year by year, the casing damage especially the casing inspection of key layer has become the focus of oilfield development process. The height of critical layer is usually about 5m, so the author puts forward that it's much more accurate to use the distributed FBG sensor as the short distance measurement method to guarantee the precision, and coupled with the traditional temperature compensation method of FBG strain monitoring. With a special installation process and the application of 40-Caliper logging tool to get the FBG' s azimuth, we get real-time strain data in the process of installing casing pipe. This paper analyzes the variation of value of the casing strain in each installation stage, the theoretical calculation results are basically the same with the data got by XMAC logging method. This proves the reliability of the distributed casing deformation monitoring system which is specifically used for the key layer of casing annulus.

Abstract: The key of engineering drawing interpretation is to dig the information of engineering drawing. Considering the features of decentralizing, hiding and blurring in drawing information, this paper presents geometry complexity of drawing information. Based on this, the graphic information and dimension information that compose the drawing information are organized in three layers: discrete information organizing, same view information organizing, different views information organizing.

Abstract: A high-resolution numerical model for dam-break flow in an L-shaped channel was presented based on using the two-step finite-volume component-wise TVD (total variation diminishing) scheme, by which second-order accuracy in both time and space is achieved. Numerical simulation for open L-shaped channel flow was implemented, and velocity and water surface were obtained.