Advanced Materials Research Vols. 291-294

Abstract: Structure strength and deformation of the preliminary hydraulic press design have been calculated by the finite element method, in which two working conditions have been considered, i.e. the centre-point load condition and the eccentric load condition. To solve the surplus structure strength globally and the localized stress concentration, the combined methodology of mathematical programming algorithm and the FEM has been utilized to redesign the hydraulic press. The optimization result shows that the mass of the press has been reduced greatly and the localized stress concentration has been eliminated. Besides that, the strength and stiffness in the optimized structure still meet the performance requirements.

Abstract: In this study, the soakage extraction method and the ultrasonic extraction method were used to extract active ingredients from Artemisia annua, Artemisia sieversiana, Artemisia mongolica，Artemisia scoparia, Artemisia lavandulaefolia and Artemisia japonica. Using the orthogonal experiment design, we studied the effects of four factors: extraction time, solid-liquid ratio, fineness and extraction times, on extracting active ingredients from Artemisia annua. We also optimized the extraction conditions of the ultrasonic wave method. The results showed that 95% ethanol solution was the best solvent for extracting components in these six species of Artemisia. The best extraction method was ultrasonic extraction method. The optimum extraction conditions of ultrasonic extraction were 1:20 of solid-liquid ratio, one time of extraction, 40 of degree of fineness and 40 minutes of extraction time.

Abstract: Engine bench scale test was performed to compare the existing flameproof diesel to the general diesel engine, monitor the change of power, torque and smoke in the fixed revolving speed, process the data, and then compare and analyze the flameproof diesel performance, put forward the improved blue print and conduct the experimental comparison. At last, data basis will be provided for the flame-proof diesel researching and designing.

Abstract: Earth observation satellite system (EOSS) is the main space platform collecting ground information. Optimization of EOSS is difficult, as it is a complex system referring a great deal of design variables and uncertain factors. Therefore, an optimization framework based on design of experiment and surrogate model is proposed. Design of experiment is used to generate simulation plan, which will greatly cut down cost of simulation. Then surrogate model is built to analyze simulation data and approximate real EOSS. Genetic algorithm and improved general pattern search method are adopted to solve the model. According to the framework, a case study is carried out. The final results illustrate the framework is useful and effective for the problem of EOSS optimization.

Abstract: In order to improve the riveting precision, the finite element method and topological optimization design based on the variable density method were employed to design the pedestal of horizontal rocket rivet fixture. Topological optimization model was set up based on static analysis of the original designed pedestal under various typical load cases. Topological optimization results of various load cases were compared with original pedestal. The result showed deficiencies of the original pedestal, and a new model was built based on topological optimization results. The analysis of topological model was carried out by applying the finite element method. The results show that the stiffness of pedestal was remarkably improved; the stress distribution was more homogenized and the displacement of the guide rail was decreased after optimization. This method could also provide reference and guidance for designing other complicated structures.

Abstract: Based on the Reynolds time-averaged N-S equations and standard k-ε two-equation turbulent mode, using multiple reference model and wall function method, the inner flow fields were simulated which is a part of three different kinds of impeller on stamping and welding multistage centrifugal pump by CFD software FLUENT. The characteristic of internal flow on multistage pump was analyzed base on the calculated results, so as to reveal how the flow regulation influences performance of pump. The result shows the internal flow condition in the distort-type impeller pump is more reasonable than the other two groups, there is not the flagrant whirlpool and the capability of cavitation-resistant is strong.

Abstract: This paper described how to apply the lag comparator of the two-state modulation circuit to the development of the current-controlled two-state modulation technology which, under the control of a micro-computer, is used to a new type of dynamic electronic load of power supply for the detector of the starting property and capability of the battery for aircraft. Based on the quantitative analysis of the lag comparator of the two-state modulation circuit, the inclusion is drawn that the system is an excellent dynamic electronic load and controlled current amplifier. The result and curves of the detection and imitation detection of batteries are given in the paper.

Abstract: In this paper, according to the base-adaptive detecting method of harmonic current for APF, there had contradiction between detecting accuracy and dynamic response. It had been proved that this system is a symmetrical notch-filter. Based on analysis above, this paper is proposed improved-adaptive detecting method. A low-pass filter has been in base-adaptive system. We first discussed the stability of improved system. Then theoretical analysis and simulation test shows the bandwidth had been reduced nearby reference frequency. Simulation had showed that the dynamic performance was in a period and the harmonic distortion rate was no more than 1.7%.

Abstract: A Circle-shape is an important figure in most small rule mechanical parts, and usually be measured to get the radius or used as a stand calibration mark. In this paper, a 2-D circle measurement system for small rule mechanical parts based on machine vision is designed and built. The basic components and work principle of the machine vision measurement system are introduced, and the measurement produce is designed and discussed. An available algorithm for circle contour detected and fitted is described. Using this algorithm, the measurement software flow and architecture are built and the software system realized in the Microsoft visual studio program platform. Certainly, the calibration of machine vision system is introduced also. Using the system and method introduced above, an experiment is designed to measure the outer ring radius of one certain model bearing. The measured data is processed and analyzed. Through the experiment and result, it can be found that the measurement system can get relatively high precision and the measurement method is relatively steady, and the system precision and speed can be suit for the demand of on-line and real-time circle measurement.

Abstract: A set of integrative irrigation fuzzy control system is designed to the question of the north field crops irrigation in this paper. In this system, the biogas digester, generating system, irrigation system, and control system are combined organically; the power needed is supplied by the biogas generator; the signals of soil moisture and air temperature are collected by the PLC; according to the control scheme that mainly controls soil moisture while air temperature is considered secondarily, a three-dimension fuzzy controller is designed to irrigate precisely; the local and remote communications are realized via the Ethernet and GPRS respectively; four monitoring modes (local operator monitor, SMS, website and C/S client) are designed in this system. The automatic irrigation system can save water, power and fertilizer at the same time.