Performance evaluation on field synergy and composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter

In order to reveal the mechanics of composite regeneration by coupling cerium-based additive and microwave for a diesel particulate filter, a composite regeneration model by coupling cerium-based additive and microwave for a diesel particulate filter was established based on field synergy theory. Performance evaluation on field synergy and composite regeneration of the diesel particulate filter was conducted by using the vortex crushing combustion and field synergy mathematical models. The results show that the peak temperature of the particulate filter body reaches 1180-1190 K when the regeneration time is 175 s, and there are optimal coordination degree between the velocity vector and temperature gradient of the filter body and the maximum ratio0.56-0.60 of the best burning regeneration region is obtained. Accordingly, the largest regeneration combustion rate inside the particulate filter body and the highest regeneration efficiency at the moment are achieved.     

Effect of blade pitch angle on aerodynamic performance of straight-bladed vertical axis wind turbine

Wind energy is one of the most promising renewable energy sources, straight-bladed vertical axis wind turbine（S-VAWT） appears to be particularly promising for the shortage of fossil fuel reserves owing to its distinct advantages, but suffers from poor self-starting and low power coefficient. Variable-pitch method was recognized as an attractive solution to performance improvement, thus majority efforts had been devoted into blade pitch angle effect on aerodynamic performance. Taken into account the local flow field of S-VAWT, mathematical model was built to analyze the relationship between power outputs and pitch angle. Numerical simulations on static and dynamic performances of blade were carried out and optimized pitch angle along the rotor were presented. Comparative analyses of fixed pitch and variable-pitch S-VAWT were conducted, and a considerable improvement of the performance was obtained by the optimized blade pitch angle, in particular, a relative increase of the power coefficient by more than 19.3%. It is further demonstrated that the self-starting is greatly improved with the optimized blade pitch angle.     

Mechanism on simulation and experiment of pre-crack seam formation in stope roof

The pre-crack blast technology has been used to control the induction caving area in the roof. The key is to form the pre-crack seam and predict the effect of the seam. The H-J-C blast model was built in the roof. Based on the theories of dynamic strength and failure criterion of dynamic rock, the rock dynamic damage and the evolution of pre-crack seam were simulated by the tensile damage and shear failure of the model. According to the actual situation of No. 92 ore body test stope at Tongkeng Mine, the formation process of the pre-crack blast seam was simulated by Ansys/Ls-dyna software, the pre-crack seam was inspected by a system of digital panoramic borehole camera. The pre-crack seam was inspected by the system of digital panoramic borehole in the roof. The results of the numerical simulation and inspection show that in the line of centers of pre-hole, the minimum of the tensile stress reaches 20 MPa, which is much larger than 13.7 MPa of the dynamic tensile strength of rock. The minimum particle vibration velocity reaches 50 cm/s, which is greater than 30-40 cm/s of the allowable vibration velocity. It is demonstrated that the rock is destroyed near the center line and the pre-crack is successfully formed by the large diameters and large distances pre-crack holes in the roof.     

Sulfur poisoning mechanism of three way catalytic converter and its grey relational analysis

Combining a detailed catalytic surface reaction mechanism with noble metal and promoter elementary reactions, a new three-way catalytic converter（TWC） reaction mechanism is established. Based on the new mechanism, steady condition numerical simulation is carried out, and the change of light-off temperatures and conversion efficiency with various SO2 contents is obtained. By grey relational analysis（GRA）, the relational grade between conversion efficiency and SO2 content is obtained. And, the result shows that SO2 content has the most important influence on C3H6 and NOX conversion efficiency. This provides an important reference to the improvement of activity design of TWC, and may provide guidance for the condition design and optimization of TWC.     

Simulation of hydrogen diffusion in welded joint of X80 pipeline steel

Hydrogen diffusion coefficients of different regions in the welded joint of X80 pipeline steel were measured using the electro-chemical permeation technique. Using ABAQUS software, hydrogen diffusion in X80 pipeline steel welded joint was studied in consideration of the inhomogeneity of the welding zone, and temperature-dependent thermo-physical and mechanical properties of the metals. A three dimensional finite element model was developed and a coupled thermo-mechanical-diffusion analysis was performed. Hydrogen concentration distribution across the welded joint was obtained. It is found that the postweld residual hydrogen exhibits a non-uniform distribution across the welded joint. A maximum equivalent stress occurs in the immediate vicinity of the weld metal. The heat affected zone has the highest hydrogen concentration level, followed by the weld zone and the base metal.Simulation results are well consistent with theoretical analysis.     

基于两相流动的铝电解槽磁流体流场数值仿真

为了对铝电解槽内磁流体的两相流动和界面波动进行深入了解,通过ANSYS和CFX相结合的方法,把洛伦兹力作为动量源相,对160kA铝电解槽内的磁流体流动进行了两相流数值仿真.仿真结果表明：铝液和电解质的流动均呈两个漩涡;铝液的平均流速为0.1476m/s,最大流速为0.2879m/s;电解质的流速偏小,平均流速为0.1165m/s,最大流速为0.286.6m/s;电解质和铝液的界面变形范围为-0.029~0.035m.将流速计算结果与实测值进行了对比,表明对基于两相流动的铝电解槽内磁流体进行数值仿真可以帮助了解铝电解槽内的流场,为进一步优化研究提供了依据.     

Collaborative prediction for bus arrival time based on CPS简

To improve the accuracy of real-time public transport information release system, a collaborative prediction model was proposed based on cyber-physical systems architecture. In the model, the total bus travel time was divided into three parts： running time, dwell time and intersection delay time, and the data were divided into three categories of historical data, static data and real-time data. The bus arrival time was obtained by fusion computing the real-time data in perception layer together with historical data and static data in collaborative layer. The validity of the collaborative model was verified by the data of a typical urban bus line in Shanghai, and 1538 sets of data were collected and analyzed from three different perspectives. By comparing the experimental results with the actual results, it is shown that the experimental results are with higher prediction accuracy, and the collaborative prediction model adopted is able to meet the demand for bus arrival prediction.     

电动客车外形设计与外流场数值模拟

针对电动汽车的特点 ,提出了旨在减小客车车身阻力系数的外形设计方案 ;并运用 Fluent软件对客车车身外围流场进行了数值模拟 ,得到了客车的空气动力特征和流场细节 ,为获得最佳的空气动力性的客车设计提供了直观依据     

基于STD总线过程控制系统硬件设计

使用计算机过程控制系统来控制铝的电解过程,采用STD总线过程控制,由1台上位机控制5台工业控制机,每台工控机再分别控制相应的生产过程．结果表明：该控制系统有效改善了传统电解铝生产过程,并有效解决了电解铝生产过程中各项指标的实时监控,避免了生产现场的危险性,提高了生产效率．STD总线过程控制系统硬件设计具有扩展方便,便于维护,使电解铝生产在最佳工作状态,提高了电解铝产量和质量．     

STD总线工业控制机在过程控制中的应用

目的采用抗干扰能力强的STD总线工业控制机作为控制主机,解决铝电解过程中的干扰问题,提高控制性能.方法控制系统硬件采用模块化、组合化方法,具有扩展方便,便于维护等特点;软件设计遵循结构化和模块化设计原则,采用了先进的控制思想,对电解槽不同的工作状态,采用不同的控制策略,使电解槽工作在最佳的工作状态.结果STD总线工业控制机系统可靠性高,便于维护,抗干扰能力强,动态性能好,稳态精度高,运行效果良好.结论STD总线工业控制机对复杂的生产过程,特别是扰动大的生产过程,具有很强的适用性,可大大提高控制效果.     

Numerical simulation for deformation of multi-layer steel plates under underwater impulsive loading

To further understand the dynamic deformation and impact resistance of thin-plate hull structure under impulse wave,the deformation of multi-layer steel plates under underwater impulsive loading has be...     

500 kA铝电解槽磁场数值模拟及测试分析

利用 SolidWorks 三维建模及 COMSOL三维仿真模拟软件,对500 kA铝电解槽进行数值模拟. 对某厂家500 kA铝电解槽进行磁场测试,测试结果与模拟结果吻合较好. 得出500 kA铝电解槽的磁度分布,并对500 kA铝电解槽进行磁场优化,通过增加立柱母线和槽周母线到铝电解槽的距离降低立柱母线与槽周母线对铝液层的影响. 优化使得铝液层在Z轴方向上磁场分布趋于均匀稳定. 为改善生产工艺技术条件提供了技术支持.     

铸铝母线切削设备设计思路探讨

分析了铸铝母线加工的工况特点，提出了铸铝母线切削加工设备的设计思路，并比较成功地解决了电解铝安装技术难题。     

大客车侧翻耐撞性的结构设计方法

为了提高仿真结果的准确性,降低产品研发成本和缩短设计周期,提出动态仿真技术与试验相结合的大客车侧翻耐撞性结构设计方法.以某型大客车为例,建立原始车型的侧翻碰撞有限元模型,按照欧盟ECE R66法规对该车进行动态仿真分析;对原有车型进行侧翻试验,根据试验结果对侧翻碰撞仿真模型进行对标.仿真与试验结果表明：在侧翻碰撞过程中,车体变形过大,侵入了乘客生存空间,车身局部结构出现凹陷现象.对车身侧墙和车顶等部位作了多次结构改进,通过仿真分析来确定改进结构的侧翻耐撞性能,改进车顺利通过了ECE R66侧翻试验认证.     

基于CANoe的车载通信网络设计与仿真

在汽车设计初期,采用CANoe软件设置和仿真总线网络上发动机、转向灯、仪表盘等节点间的通信,并根据仿真测试结果对报文发送频率、信号延迟时间进行调整,以满足总线负载率不超过30％的要求.在设计后期的实车测试中,连接物理CAN总线,对物理CAN总线上的各个模块进行监测.仿真结果表明,该系统能有效反映真实电子控制单元(ECU)的通信情况.     

一个基于ACE的微总线的设计与实现

针对分布式的应用系统，设计了一个基于ACE的微总线架构。该架构将互联的网络作为软总线的物理基础，挂接在总线上的构件按照协议具备了驱动能力，构件之间的互操作问题采用Peter Herzum互操作参考模型来解决。构件只有分工不同。不分优先级，彼此之间是平等的。     

LIN总线通信展示板的实现

介绍了LIN总线及其通信特点，分析了LIN总线通信的帧结构和通信协议；针对LIN总线在汽车低速通信中的模拟应用，设计了LIN总线硬件电路和LIN展示板，详细阐述了其功能和软件流程；展望了LIN总线的发展前景。     

Long-term settlement prediction of high-speed railway bridge pile foundation

The process and characteristics of loading on high-speed railway bridge pile foundation were firstly obtained by means of field research and analysis, and the corresponding loading function was presented. One-dimensional consolidation equation of elastic multilayered soils was then established with single drainage or double drainages under multilevel loading. Moreover, the formulas for calculating effective stress and settlement were derived from the Laplace numerical inversion transform. The three-dimensional composite analysis method of bridge pile group was improved, where the actual load conditions of pile foundation could be simulated, and the consolidation characteristics of soil layers beneath pile were also taken into account. Eventually, a corresponding program named LTPGS was developed to improve the calculation efficiency. The comparison between long-term settlement obtained from the proposed method and the in-situ measurements of pile foundation was illustrated, and a close agreement is obtained. The error between computed and measured results is less than 1 mm, and it gradually reduces with time. It is shown that the proposed method can effectively simulate the long-term settlement of pile foundation and program LTPGS can provide a reliable estimation.     

VHDL语言中数值系统的研究与应用

介绍了在计算机辅助设计中运用VHDL语言进行硬件描述时常用的各种数值系统 ,讨论了不同类型电路其相应数值类型的配置原则 .针对运用VHDL语言进行系统描述和系统仿真中出现的总线冲突问题及不确定值的传递问题 ,阐明了运用判决函数解决总线冲突的方案及判决函数的算法实现 ;并简要说明了运用更大的数值系统为判决函数提供更多的结点信息来解决不确定值的传递问题的方法     

Numerical verification of similar Cam-clay model based on generalized potential theory

From the mathematical principles, the generalized potential theory can be employed to create constitutive model of geomaterial directly. The similar Cam-clay model, which is created based on the generalized potential theory, has less assumptions,clearer mathematical basis, and better computational accuracy. Theoretically, it is more scientific than the traditional Cam-clay models. The particle flow code PFC3 D was used to make numerical tests to verify the rationality and practicality of the similar Cam-clay model. The verification process was as follows： 1） creating the soil sample for numerical test in PFC3 D, and then simulating the conventional triaxial compression test, isotropic compression test, and isotropic unloading test by PFC3D; 2）determining the parameters of the similar Cam-clay model from the results of above tests; 3） predicting the sample＇s behavior in triaxial tests under different stress paths by the similar Cam-clay model, and comparing the predicting results with predictions by the Cam-clay model and the modified Cam-clay model. The analysis results show that the similar Cam-clay model has relatively high prediction accuracy, as well as good practical value.