Advanced Materials Research Vols. 308-310

Abstract: Based on the ideas of wall-guiding-spray and spatial dispersion, A new type of diesel engine double-wall-jet combustion system is designed. The effect of speed, load and injection condition on the double-wall-jet combustion system is researched by testing, on the double-wall-jet combustion system, the combustion modes for whole working condition is analyzed, the comparison of combustion and performance between the original machine with the new one is carried out. The results showed that: Instantaneous heat release rate of double-wall-jet combustion system shows a single peak. As the speed increases, the corresponding crank angle of ignition retards, the peak outbreak pressure increases and then decreases, the peak instantaneous heat release rate, the peak average temperature, the peak cylinder pressure rise ratio, and the cumulative heat release per unit mass of working gas is reduced. As the load increases, the corresponding crank angles of peak cylinder pressure and gravity center of heat release rate are postponed. With the load increasing, the ignition crank angle corresponds early at low speed, and the ignition point does not change significantly with the load at high speed. The effect of the injector hole diameter/number on the cylinder pressure and instantaneous heat release rate curve is not significant at high speed and large loads, but at low speed and large loads is significant. Cylinder pressure of 6-Φ21 injector is higher than 5-Φ25, the instantaneous heat release rate of 6-Φ21 injector has a trend of a single peak, the instantaneous heat release rate of 5-Φ25 injector has a trend of a double peak and the focus of the heat release rate postponed. With the advancing of injection timing, the ignition crank angle and combustion phase advances, the peak cylinder pressure increases. Injection pressure has little effect on the combustion characteristics. By comparison with the original machine, while maintaining the power performance of the same circumstances, the cylinder pressure and NOx emissions of double-wall-jet engine are reduced in degree, fuel consumption rate is not almost changed, and the same plane rather, smoke intensity is improved at low speed, smoke intensity at high speed smoke high-speed only deteriorates of 0.2-0.3 BSU.

Abstract: Based on the time history analysis method, some curve long-span rigid frame bridge with super high pier in Sichuan was taken as the studying case, and a studying of natural vibration characteristics and seismic response. Comparative study was emphasis carried on seismic performance between the partial curve bridge and the straight. In addition, the exhaustive research to about between crosswise relation to the structure overall rigidity contribution and to the structure and the seismic performance influence is conducted. The conclusion of the study shows that the seismic performance of the straight long-span rigid frame bridge with super high pier is surpassing the curve bridge. The curve linear has little influence to the base frequency of this kind of structure, and The rigidity is mainly effected by the bridge pier. If additionally builds the crosswise relation between the structure, the dynamic characteristic of the structure will be improved greatly. The height of this type bridge has great influence on the dynamical stability, the height is lower and the dynamical stability is better, which is more advantageous to the structure seismic behavior.

Abstract: The fault tree analysis is a widely used method for evaluation of systems reliability and safety. Dynamic fault tree (DFT) extend traditional FT by defining additional gates called dynamic gates to model these complex interactions. Markov models are used in solving dynamic gates. However, state space becomes too large for calculation with Markov models when the number of gate inputs increases. In addition, Markov model is applicable for only exponential failure and repair distributions. But in engineering, the failure mode is mostly obeyed to weibull distribution for mechanism and electronic units. Combined the weibull distribution and Markov model, this paper presents dynamic fault tree quantitative analysis method based on weibull distribution.

Abstract: Rolling steel surface defect inspection technology based on machine vision is more and more widely used. The latest progress of vision-based real-time inspection algorithm for rolling steel surface defect at home and abroad is introduced, and several key issues are analyzed. Finally, the current domestic research emphases and development trends are proposed.

Abstract: Turbocharger turbine shaft thrust bearing is the role of high-speed rotating turbine to withstand the axial force generated by the turbine shaft and a part of the axial position. Fixed on the intermediate thrust bearing on the two sides and both sides of the ring, respectively, relative sliding. Sliding contact surface produces a condition of dynamic pressure oil film structure and shape of the oil wedge. Bearing the sides of the structural design of the oil wedge slot and forming a design to solve the main content. Bearing thrust bearing stiffness and rotation in the process of stress state and the smooth line is to improve the bearing life. Rotating turbine shaft to ensure the accuracy of key factors. Method of lubricating oil to the oil and oil Xie in the shape and precision bearings to ensure the prerequisite conditions and service life.

Abstract: In order to fix on the inner connection of modification coefficient and bend strength, the static analysis of profile-shifted gear is made by applying Finite Element Method, then regression equation that revealed the relation between modification coefficient and bend strength is set up according to the Similarity Theory. Given bend stress of a standard gear, the bend stress of any profile-shifted gear with the same teeth can be calculated from the equation.

Abstract: This paper proposed a new method of non-contact energy transmission based on ultrasonic. Firstly describes the work principle of ultrasonic non-contact power transmission, and establishes the model of the system by way of the equivalent circuit, and the system was theoretically analyzed in detail. Then the interface circuit was proposed, and the maximum load power is analyzed. The experiment results show that the energy can be efficiently transmitted within effective distance, indicating that the method has some practical value.

Abstract: In this paper, a magnetic resonance coupled wireless transfer system is studied to establish the efficiency analysis model. By analyzing the influencing factors of system efficiency indicates that the system transfer power is mainly determined to the resonance frequency, and only near the resonance frequency has achieved a maximum value. With experimentally studying the load received power varied with frequency at the transfer distance from 80cm to 120cm, we believe that the magnetic resonance coupled wireless transfer system’s optimization can be realized by controlling the frequency.

Abstract: In this paper, a magnetic resonance coupled wireless power transfer system(MRCWPTS) with series capacitor compensation is studied in order to investigate resonance frequency, and then the system transfer model is presented. Research results show that system resonance frequency is likely to occur splitting and maybe appear two or three resonance frequencies(odd /even mode resonance frequency and nature resonance frequency) in close distance under small load, which increases the system instable, and makes the system difficult to control in resonance frequency. By analyzing of the system, the distance boundary condition when resonance frequency splitting is given, under this boundary the system avoid resonance frequency splitting well, then simulation and experiment results verify the theoretical analysis.

Abstract: Based on existing pipe network monitoring system and start with the concept of The Internet of Things[1], the remote monitoring and fault diagnosis system is designed.It can make the fault diagnosis expert experiences shareable, raise user ability, reduce the system maintenance costs,and improve the management level as well.