Advanced Materials Research Vols. 945-949

Abstract: Based on the design of membrane bioreactor three-dimensional finite element model is established,Finite volume method was applied to sewage treatment in the process of membrane bioreactor internal flow field is unsteady flow numerical simulation and analysis. The results of numerical simulation can be seen at the bottom of the membrane module speed change is small, to purify sewage full contact with membrane module, the upper change is bigger, treated sewage can be quickly exhaust to the outside world. This study on flow field of the bioreactor of in-depth study, the new structure design and optimization has its far-reaching significance. Finite volume method was applied to sewage treatment in the process of membrane bioreactor internal flow field is unsteady flow numerical simulation and analysis. The results of numerical simulation can be seen at the bottom of the membrane module speed change is small, to purify sewage full contact with membrane module, the upper change is bigger, treated sewage can be quickly exhaust to the outside world. This study on flow field of the bioreactor of in-depth study, the new structure design and optimization has its far reaching significance.

Abstract: Numerical simulation in fractured media is challenging because of the complex microstructure and the coupled fluid flow in porous and fractured media. In this paper, we have extended the global multiscale finite element method (GMsFEM) to study the fluid flow in fractured media with a dual porosity model. By using the fine-scale solution at t=0 to determine the boundary conditions of the basis function, local and nonlocal informations are reflected in the basis functions. As a result, an accurate solution can be achieved in the coarse scale. Numerical example demonstrate that the solution of GMsFEM is highly consistent with the fine-scale solution of FEM. Furthermore, GMsFEM provides a great computational efficiency.

Abstract: The paper takes the twisted blades of fluorine plastic centrifugal pump as the research object. It used the flow field calculation software Fluent based on average N-S equations and standard k-ε turbulent model, and adopted the method of SIMPLEC algorithms, it conducted the numerical simulation on uncompressed flow of fluorine plastic centrifugal pump of twisted blades in different conditions. The results show that the relationship between the lift,shaft power,efficiency and flow, are compared with experimental ones, and it shows that the predicted performance coincides with the experimental one well, the simulation provides theoretical basis for the optimizing design.

Abstract: The major problem in ventilation systems designing is an empiric range of parameters of an air cavity and rustics between cladding panels which results in unventilated layers emergence. Whereas insufficient air interchange causes icing of as substructure elements which come out into a ventilated air cavity as facing outer layer in winter period, and reducing of heat-protective properties of the structure in whole. The aim of this survey is to elaborate the methods meant for calculating the parameters of hydraulic airflow in a ventilated air cavity which allow determining rational and optimal dimensions of hydraulically optimal air cavity in rainscreens of buildings and other constructions. As an outcome it has been specified that it is necessary to design a ventilated rainscreen cladding with a ventilated air cavity expanding from bottom to top with the purpose to reduce the losses.

Abstract: This article has analyzed the stress and the intensity interference theory, has mentioned the automobile spare part tradition safety coefficient design and between the modern probability design difference and the relation emphatically.

Abstract: The research on equipment combat resilience evaluation is an important part of equipment combat resilience. Based on analyzing the form and the function of the equipment combat resilience evaluation system, a set of intelligent and integrated evaluation system is designed and developed by using UML Object-oriented Modeling Language. The system can achieve economic, quick and effective evaluation results by applying the Set Pair Analysis .The theory result of the evaluation is consistent with the experiment result by an example of the combat resilience evaluation of certain fighter.

Abstract: EST use the uniform weights to evaluate the pipeline, making the evaluation results do not truly reflect the risk profile of pipeline, so base on the EST , introduce the entropy theory to improve it. Determine the weight factors of every risk factor by calculating the entropy value of every accident factor, clear out the influence of various factors on the pipeline, make risk scoring methods can be more reasonable, accurately reflect the risk of pipeline case. At last, north line pipeline are evaluated by applying the improving method.

Abstract: In order to overcome the problem that the maintenance date for NC machine parts was lacking, this paper proposed a maintainability prediction method based on comparing with basic unit. The biggest difference from traditional methods was that the traditional methods analyzed parts, but in this method, failure modes were analyzed and interval number was used to express expert opinions. The maintenance action for each failure mode was decomposed into several basic maintenance tasks. Comparatively speaking, the method had more adequate data and higher accuracy. Finally, the method was illustrated with an example. The analysis results showed that the method was feasible for the maintainability prediction of NC machine tools. It could solve the existing principal problems and provide a new idea for predicting maintenance in the field of NC machine tools.

Abstract: In order to solve the difficulties existing in course of complex system reliability modeling, a novel method was proposed in this paper. According to the analysis sequence, from FMEA to FTA to BN, a BN can be constructed by making full use of the helpful information in the results of FMEA and FTA. The reliability of complex system can be analyzed based on uncertainty-expression ability and bidirectional-reasoning ability of BN. For demonstrating the effectiveness of this method, aim at the failures of gears in wind turbine gearbox, a BN for system reliability analysis was constructed.

Abstract: This paper introduces a new method, named E-Bayesian estimation method, to estimate failure rate in zero-failure data. The definition of E-Bayesian estimation of the failure rate is given, based on the definition, the formulas of E-Bayesian estimation and hierarchical Bayesian estimation of the failure rate were provided, and properties of the E-Bayesian estimation, i. e. relations between E-Bayesian estimation and hierarchical Bayesian estimation, was discussed. Calculations were performed on practical problems, showing that the proposed new method is feasible and easy to operate.