基于过渡边的细化算法及其在舱口角隅处的应用

为了获得更精确的分析结果,在集装箱船舱口角隅应力集中的区域,采用添加过渡单元的方法对原有的粗网格进行细化,然后对局部模型再次进行有限元分析.以此提出一种自动的有限元精细划分的算法.介绍构造过渡单元的方法,并根据计算出的迭代次数,得到细网格后进行分析.最后的结果表明,细化网格后生成的新单元与母单元属性保持一致,对于应力变化剧烈的区域,分析结果好于整体分析的结果.     

On the development of Bi-Level Integrated System Collaborative Optimization

Bi-Level Integrated System Collaborative Optimization (BLISCO) is a new multidisciplinary design optimization (MDO) method based on Bi-Level Integrated System Synthesis (BLISS) and Collaborative Optimization (CO). The key ideas of BLISCO are to replace compatibility constraint with the sum of coupled outputs as an integrated objective of subsystems and to decompose design variables into system design variables and subsystem design variables, while maintaining the collaborative mechanism of CO. One mathematical example and two engineering problems are used to test the effectiveness of BLISCO under the platform of iSIGHT^TM. Results from the test cases show that BLISCO has satisfactory convergence, accurate result and reliable robustness.     

一种飞行试验测试系统设计

介绍了一种飞行试验测试系统的工作原理和软硬件设计方法,该系统主要由压力传感器、加速度传感器、基于PC104总线的数据采集系统、电源控制电路、数据输出设备组成,通过试验证明,该测试系统运行可靠,而且具有很好的抗冲击性和稳定性,为研究提供了充分准确的依据.     

带自由液面的艇/桨干扰特性数值模拟与验证研究

带自由液面的艇/桨干扰特性研究是水动力学领域的重点与难点.此文采用数值模拟方法研究了潜艇近水面航行时的艇/桨干扰特性.首先介绍了计算方法:流场采用RANS方法结合RNGk -ε湍流模型求解;自由液面捕捉采用VOF方法;螺旋桨运转采用滑移网格方法;带螺旋桨潜艇表面与计算域内全部采用结构化网格进行离散.然后,对于SUBOFF潜艇模型在不同浸深下的阻力特性进行了数值模拟,分析了自由液面对于模型阻力的定量影响.最后,对于带螺旋桨的SUBOFF潜艇模型在深潜与近水面状态下的艇后推力、扭矩进行了数值模拟,分析了自航因子,研究了艇/桨干扰特性.计算结果与试验结果进行了详细的对比分析,验证了计算方法与计算结果的可靠性.本文的工作可为将来构建数值拖曳水池提供技术支撑.     

空泡两相流场PIV测试技术研究

基于图像分析和TR-PIV建立了一套空泡周围非定常两相流场的PIV测试技术,并对分析方法进行详细的描述与试验验证.利用本文针对空泡现象选择的图像处理方法可以同时获取空泡的轮廓边界和空泡周围流场信息.三维水翼空泡流场试验表明,该方法适用于空泡现象的研究和分析,可获取高时间和空间分辨率的量化空泡发展过程以及空泡生长、脱落和溃灭过程中空泡壁面附近和周围流场的量化信息.     

PRESSURE DISTRIBUTION DETERMINED BY USING MEASURED VELOCITY FIELD DATA AND RANS EQUATIONS

The current paper presents the result of a study on determining the pressure distribution along the surface of a foil section by using measured velocity field data and the Reynolds Averaged Navier-Stokes equations. The results are compared with the measured pressure data and show its satisfaction. It is a try to find a new way to determine pressure by combining the experimental data and CFD method.     

A machine vision system for on-line removal of contaminants in wool

The current techniques in the textile industry cannot efficiently remove polypropylenes, packing materials and black-pigmented fibres from wool. Their presence reduces the value of the textiles considerably because they cannot be dyed and used as wool. To solve the problem, a machine vision system, consisting of a colour line-scan CCD camera, frame grabber, host computer and air-jets, is investigated and presented in this paper, which can be used to identify and remove the contaminants in scoured wool. The key techniques, the image acquisition system, algorithms and mechatronic sorting system are described in detail. Finally the performance of the machine vision system is analysed and further research work is discussed.     

T-Stress in Elastic-plastic Crack-tip Fields

A ligament field ahead of a crack tip for Model-I plane strain problem in a power-law hardening material is developed. Based on this solution, a formula for the critical value of J-integral in terms of T-stress for an elastic-plastic material is derived. T-stress effects on fracture toughness are discussed.     

THE SECOND-ORDER HYDROELASTIC ANALYSIS OF A SWATH SHIP MOVING IN LARGE-AMPLITUDE WAVES

1. INTRODUCTION During the last two decades, the linear three-dimensional hydroelasticity theory[1,2] has been extensively applied to a wide range of fluid-structure interaction problems in the field of naval architecture and marine engineering[3-5]. Thes…     

债券监控模块设计与实现

根据债券业务要求，设计并实现了对债券交易平台的监控。提出了篝中管理债券客户服务器的思想，同时按客户类型和允许连接的最大客户端Client数进行了License的设计，并且实现了客户服务器的远程更新，用实际案例说明该设计思想的主要实现过程。