大型甲板船台悬浮定位技术

本文概述了大型甲板船台悬浮定位合拢技术中的几个问题，以及这项技术在本公司第三事业部1.1万吨级滚装船建造工艺中的实施状况和成果，最后对解决存在的问题提出了建议。     

25B型客车照明电源系统的改进

由于25G型空调软卧车、餐车备用量严重不足,怀化北车辆段只好把25B型软卧车、餐车编挂到大列空调车编组中运用.运用过程中,多次发生因J5型发电机供电系统故障而造成车厢熄灯事件.究其原因,就是因为这种车的照明系统只能由本车供电,而不能由集中供电系统供电.当本车5 kW发电机供电系统出现故障时,该车的照明就无法实现.为了改变这种缺陷,我们对25B型车的照明电源系统进行了改进.     

Gas turbulence modulation model for gas-solid flows in two-fluid approach

Turbulence enhancement by particle wake effect is studied by numerical simulation of gas turbulent flows passing over particle under various particle sizes, inlet gas velocities, gas viscosity, gas density and the distance of particles. By performing dimension analysis and using the form of gas-particle interaction source term for reference, a new semi-empirical turbulence enhancement model by the particle-wake effect is proposed. The turbulence model is then incorporated into second-order moment model for simulating gas-particle flows in a horizontal channel with different wall roughness and a sudden-expansion chamber. The results show that this model is with higher calculating accuracy than another two turbulence models in comparison with the experimental results.     

Comparison of gas particle flow prediction from large eddy simulation and Reynolds-averaging Navier-Stokes modeling

In order to account for the effect of particle existence on gas-particle turbulence flow in large-eddy simulation (LES), a new gas-particle turbulent kinetic energy subgrid-scale (SGS) turbulence model is established, and the effect of particle wake is also considered in gas turbulent kinetic energy SGS turbulence model. Simulation of gas-particle turbulence flow in backward-facing step is carried out by LES using present model and by unified second-order moment (USM) model. The prediction statistical results including mean velocity and fluctuation velocity by LES using present model are in reasonable agreement with the experimental results. It is shown that present model is with higher calculating accuracy than USM model, which indicates that the turbulent kinetic energy SGS turbulence model is suitable.     

微型电动车非承载式车身轻量化研究

介绍某微型电动车非承载式车身骨架的研制过程,包括应用拓扑优化方法确定骨架结构的空间布置,以及应用普通机械优化方法确定合理的梁截面尺寸.进行了非承载式骨架车身悬置的设计和分析,并通过对包括该骨架式车身的整车进行碰撞仿真分析,改进了车身骨架结构.     

外环运河河道综合整治工程要点

随着我国经济水平的提升,水利工程也成了城市重点建设的一项内容。运河作为城市的重要功能水道,对城市运输,以及整体环境建设都具有重要的意义,需要用科学治理的方式予以应用,以保障其功能发挥。     

实现“两个根本性转变”是至关重要的课题

实现“两个根本性转变”是至关重要的课题力行编者的话党的十四届五中全会提出的我国经济和社会发展“九五”计划及２０１０年远景目标，确定了实现体制转轨和增长转型两个根本性转变的战略。这是实现我国经济健康发展和社会全面进步的重要保证。体制转轨是生产关系的调整...