Characteristics of entropy generation and heat transfer in a microchannel with fan-shaped reentrant cavities and internal ribs

Three-dimensional laminar fluid flow and heat transfer in a micro heat sink with cavities and internal ribs are investigated us-ing numerical methods. Moreover, according to the second law of thermodynamics, the model of entropy generation is also established for variable cross section of the microchannel. The simulation encompasses Reynolds number of 198-600, relative cavity height e1/Dhvalues of 0-0.65, relative rib height e2/Dhrange of 0-0.2167. The results show that the effect of relative rib height on entropy generation is significant, while the relative cavity height has little effect on it. The combined effect of cavities and ribs in the microchannel has better performance of heat transfer than the smooth microchannel under similar conditions. Extensive simulations are conducted to collect data on the characteristics of heat transfer and fluid flow in a micro heat sink with cavities and internal ribs. Using these data, correlations for Nusselt number and friction factor in terms of Reynolds number and the geometry of cavity and rib have been developed.     

Modeling deterministic echo state network with loop reservoir

Echo state network (ESN),which efficiently models nonlinear dynamic systems,has been proposed as a special form of recurrent neural network.However,most of the proposed ESNs consist of complex reservoi...     

GMRP组播功能测试

GMRP协议是针对于二层交换机的组播测试协议。通过详细的探讨,可以了解以太网交换机组播技术的实现和使用,组播协议GMRP更深层次的理解,及其在交换机组播测试中的应用。通过GOOSE报文来检测以太网交换机的组播功能。     

曲线梁桥计算理论与设计实践问题探讨

曲线梁桥以其良好的适应性和动态美感在我国桥梁设计界出现频率逐年增高,然而其安全隐患和运营事故也随之出现.就此状况,从研究曲线梁桥的力学性能入手,结合工程实际对现有计算理论和设计方法进行归纳与分析,提出其中有待进一步研究解决的问题,以期为曲线梁桥的设计与实践提供参考建议.     

一类带时间约束的多工件排序优化

研究了多个工件在多台机床上顺序加工,满足不同工件时间约束下总体加工时间最短的排序问题。建立了该问题的0-1整数优化模型,编写了基于LINGO软件的求解方程,算例表明了该模型的有效性。     

煤矸软卧地基上建筑墙体开裂的事故分析和处理

实践证明,煤矸地基为不良软土地基,工程上具有塑性、流变等不稳定现象,极易造成建筑物失稳.故而,分析了煤矸地基的物理特性,提出控制方案及控制对策.实施后结果证明可以保证地基的稳定,满足了工程需要,产生显著的经济效益.     

基于UC3637的永磁直线电机控制系统

由于旋转电机和直线电机的结构不同,其控制系统也有很大差异。该文介绍了1种将无刷直流旋转电机专用芯片UC3637在直线电机控制系统的应用实例,介绍了硬件和软件结构以及实验结果和应用。     

基于GSI的交互式网格安全认证研究

网格认证是网格安全的重要组成部分,是对网格实体身份有效性进行确定的过程。网格环境下虚拟组织为认证提出了新的要求。介绍了网格环境下虚拟组织的特点,阐述了网格认证的基本要求,分析了几项常用的认证技术不适合多结点网格认证的原因,在此基础上分析了Globus项目中基于GSI认证的相关技术及概念。网格技术是一项不断发展的技术,网格认证也处于不断完善之中。