基于SolidWorks Flow Simulation的车载半导体制冷箱的仿真分析

半导体制冷箱的制冷效率是评价制冷箱性能的重要参数,因此提高制冷效率是设计的重点。对制冷装配体与制冷箱的耦合方式进行优化,并运用Solid Works Flow Simulation软件进行仿真分析。对比得出,在制冷装配体风扇外表面与制冷箱内壁重合、所开槽尺寸为41.7mm×41.7mm×20mm、风扇为吸气时,制冷箱内温度最低。

Demands, Resources and the Three Dimensions of Flow at Work. A Study among Professional Nurses

Within the healthcare context is very important to foster the dynamics leading to positive experiences at work, in order to promote work motivation and well-being. This study investigated the influence of some personal and job resources and of some job demands on the three dimensions (absorption, work enjoyment, intrinsic work motivation) of flow at work, on the basis of Job Demands-Resources Model. Flow at work is an inner experience arising during an activity in which people are immersed, feel motivated and enjoy it. Studies suggest that resources are the main antecedents of the flow experience. Respondents to the questionnaire were 197 nurses. Multiple regressions were performed to detect the resources and the demands that influence the three dimensions of flow at work. As expected, resources positively influenced the dimensions of flow at work, particularly work enjoyment. Job demands positively influenced absorption and negatively influenced the other two dimensions of flow at work. Human resources managers should promote flow at work supporting the availability of resources and monitoring the job demands.

Design and Implementation of Visualized Workflow Modeling System Based on B/S Structure

According to the necessity of flexible workflow management system, the solution to set up the visualized workflow modelling system based on B/S structure is put forward, which conforms to the relevant specifications of WfMC and the workflow process definition meta-model. The design for system structure is presented in detail, and the key technologies for system implementation are also introduced. Additionally, an example is illustrated to demonstrate the validity of system.

eWorkFlow工作流在信息化管理系统中的应用

随着信息化的发展,对企业的信息化管理系统的发展提出了更高的要求。本文从e Work Flow工作流出发,并以某公司的安全监控信息管理系统为例,阐述了e Work Flow工作流在信息化管理系统中的应用。通过e Work Flow工作流与此安全监控信息管理系统的集成,实现了该企业信息化、电子化及无纸化的办公,且实现了此安全监控信息管理系统与公司的OA系统、资产管理等系统无缝结合。

基于SolidWorks Flow Simulation的热电制冷箱装配体安装架构的仿真优化

为了提高热电制冷箱的制冷性能,对市面上常见的热电(半导体)制冷箱进行分析,并对制冷箱的制冷装配体与箱壁之间的架构方式进行探究。采用仿真工具SolidWorks Flow Simulation对制冷箱的制冷装配体与箱壁之间的架构方式进行建模仿真。分析了重力、风扇方向、开槽尺寸、槽内所加支架等参数对半导体制冷箱制冷性能的影响规律,结果表明:制冷箱在开槽尺寸一定时,重力方向处于箱体尺寸最长边,风扇进气方向为吸气,槽内加对称支架,并对支架的4个侧面做尽可能多的圆形镂空处理,且圆越大越好,此时热电制冷箱的制冷性能最优。

FLOW STRESS MODEL FOR HARD MACHINING OF AISI H13 WORK TOOL STEEL

An approach is presented to characterize the stress response of workpiece in hard machining, accounted for the effect of the initial workpiece hardness, temperature, strain and strain rate on flow stress. AISI H13 work tool steel was chosen to verify this methodology. The proposed flow stress model demonstrates a good agreement with data collected from published experiments. Therefore, the proposed model can be used to predict the corresponding flow stress-strain response of AISI H13 work tool steel with variation of the initial workpiece hardness in hard machining.

The Effect of Net Working Capital on Jordanian Industrial and Energy Sectors＇ Net Cash Flows Employed in Operating Activities

The primary objective of the cash flow statement is to provide useful, meaningful, and relevant information about the cash receipts and cash payments of a firm during a given period of time. Decision makers can achieve extra features of the change in net assets, the firms＇ financial position （liquidity and solvency）, and the firm＇s ability to adapt to changing circumstances by affecting the amount and timing of cash flows. Cash flow statements improve comparability as they are not affected by differing accounting policies used for the same type of transactions or events. This study aims to verify the effect of net working capital （NWC）, as an indicator of a company＇s short-term liquidity or its ability to meet short-term obligations, on Jordanian industrial and energy sectors＇ net operating cash flows （NOCF）. A simple liner regression is used to test a period of 2008-2011 in order to conclude the extent of the effect on industrial and energy sectors. The study showed that there is a significant effect of the independent variable NWC on the dependent variable NOCF among industrial and energy sectors in Jordanian market. Whereas the adjusted R-squared of test is 0.854, changes in NOCF in Jordanian industrial and energy sectors have been described by NWC. Also, the study reached that the utilities and energy sector has the lowest NWC, while the mining and extraction sector has the highest. And, electrical industries sector has the lowest NOCF, while the mining and extraction sector has the highest. Moreover, the study showed that the printing and packaging sector has the lowest NWC, while the mining and extraction sector has the highest. And, glass and ceramic industries sector has the lowest NOCF, while the utilities and energy sector has the highest.

基于Auto Manager Work Flow的工程技术综合管理系统

PDM作为一种崭新的管理模式 ,真正解决了产品数据集成问题 ,受到企业的广泛重视。基于Auto Manage Work Flow平台的工程技术综合管理系统实现了 PDM的部分功能 ,既能控制设计流程 ,又能人工实现协同设计 ,为众多拥有 EDM的企业实现

THE ENTROPY-FLOW METHOD FOR DETERMINING THE MINIMUM WORK IN AN AIR-EXHAUSTING PROCESS

The thermodynamic system consists of the entropy flow and entropy product.This paper is to define the entropy flow and to apply it to determinig the minimal work in air-exhausting processes.It is found that the minimum work depends only on the pressure at the negative-pressure space.

Analysis and modeling of web services flow using π-calculus

In order to increase the effectiveness and the reliability of web services flow, the ~r-calculus formal method is introduced as a development language for web services flow. The π-calculus overcomes inabilities of web service flow languages in demonstrating the consistency, validating the correctness and so on. The π- calculus analysis and modeling of web services flow is presented, the dynamic actions and basic activities of WS-BPEL with π-calculus formally are described, and the mapping from π-calculus expression to WS-BPEL is built. The basic construction of web services flow with the π-calculus method after the analysis of the syntax of WS-BPEL and inter-description between WS-BPEL and π-calculus is expressed. Also discussed are the approaches to web services flow by modeling from different views, and the proposed approaches through the development and modeling of an e-commerce web service flow application are illustrated.

基于MoldFlow的遥控器盖注射模设计

根据遥控器盖塑件的结构和外观形貌,采用Mold Flow软件进行最佳浇口位置、流动冷却分析,将充填过程进行可视化仿真,对塑件和模具结构进行优化设计,并采用优化方案,利用Solidworks软件完成模具的三维设计。

A New Kind of Pilot Controlled Proportional Direction Valve with Internal Flow Feedback

Proportional direction valve is one of the most fundamental elements in electronic-hydraulic control technique. Its function is to control the operating speed, direction, position, and strength of output force of the hydraulic actuator continuously. Considering the different application and the cost, the existing technique mainly includes the internal feedback valve used in open loop system, and the electronic closed loop controlled valve used in closed loop system. Because of their different mechanical structure and the gre at different in performance, it brings inconvenience for customer to select, also inconvenience for enterprise to produce. Aiming at this problem, the idea of combining the above two kinds of valves into one body is proposed first, and then the new valve＇s structure to realize this target is designed. The idea intends to apply the displacement pilot flow feedback control principle in present 2-position 2-way valve system to the proportional direction valve of 3-position 4-way system. Newly designed feed forward controller can decouple the interference between the internal feedback and the electronic closed loop. Redundant conversion is designed to electronic switch mode. Experiment on dynamic and static characteristic of new proportional direction valve in internal feedback control mode and electronic closed loop control mode is discussed to prove the new theory is correct. Although the new valve is of excellent dynamic response characteristic, its steady control characteristic in open loop control mode needs to be improved further. The research results prepare one new fundamental element for electronic-hydraulic control technology.

Research on numerical simulation of flow field in shallow-bath dense-medium separator

介绍了浅槽重介分选机的结构、工作原理和技术特点，并采用Fluent软件，对浅槽重介分选机内部的流场进行了分析和研究，得出了各主要位置的速度和速度变化规律。揭示了浅槽重介分选机在分选过程中的悬浮液体流场形态及运动规律，以为其结构设计和改进提供理论依据。

Study on Quantitative Relationship between Surface Wettability and Frictional Coefficient of Liquid Flowing in a Turbulent Horizontal Pipe

This paper had investigated the effects of surface wettability on the frictional resistance of turbulent horizontal flow for tap water in five pipes made of various materials and four kinds of liquids in a polytetrafluoroethylene(PTFE) pipe,with the same inner diameter of 14 mm. Pressure drops were measured under different flow rates through an experimental flow loop. The contact angles and adhesion work of liquids in contact with pipe surfaces were determined using a contact angle meter. Based on the dimension and regression analyses, two kinds of modified relationships between the frictional coefficient and the surface wettability were established according to the measured results corresponding to tap water in five pipes and four liquids in PTFE pipe. The experimental results show that the surface wettability has some influence on frictional coefficient of the studied liquids flowing in macroscale pipes, and the frictional coefficient decreases with the increase of the contact angle at the same Reynolds number. Meanwhile the effect of wettability on the hydrophobic surface is greater than that on the hydrophilic one. The frictional coefficients predicted by the modified formulas have verified to be in good agreement with the experimental values, the relative errors of which are within ±6% and ±3% for the tap water flowing in five different pipes and four kinds of liquids flowing in PTFE pipe, respectively.

Comparison on Mathematical Models for Description of Flow Curves of Stable Austenitic Steels

The flow curves were measured for the stable austenitic steels 304L and 304LN by means of tensile test at room temperature,which are described by the models σ=K1εn1 + exp(K2 + n2ε), σ=Kεn1+n2lnε and σ=σ0+Kεn (where, K1, K2, n1 andn2; K, n1 and n2; σ0, K and n are constant). The comparison of the maximum deviations and the consideration of thevariation of the work hardening rate with true strain show that the flow curves for the austenitic steels 304L and 304LN canbe described by the model σ=Kεn1+n2 lnε at higher precision.The derivatives of the models σ=K1εn1 + exp(K2 + n2ε) and σ=Kεn1+n2lnε with respect to true strain, exhibit theextreme at low true strain. This inherent character indicates that both models are unsuitable to describe the part of the workhardening rate curve at low true strain.

NUMERICAL CALCULATIONS OF GASEOUS REACTING FLOWS IN A MODEL OF GAS TURBINE COMBUSTORS

This paper describes the numerical calculations of gaseous reaction flows in a model of gas turbine combustors. The profiles of hydrodynamic and thermodynamic patterns in a three-dimensional combustor model are obtained by solving the governing differential transport equations. The well-established numerical prediction algorithm SIMPLE, the modified k-ε turbulence model and k-ε-g turbulent diffusion flame model have been adopted in computations. The β function has been selected as probability density function. The effect of combustion process on flow patterns has been investigated. The calculated results have been verified by experiments. They are in remarkably good agreement.

An analysis method of injection and production dynamic transient flow in a gas field storage facility

A dynamic transient flow analysis method considering complex factors such as the cyclic injection and production history in a gas field storage facility was established in view of the limitations of the existing methods for transient flow analysis and the characteristics of the injection-production operation of strongly heterogeneous gas reservoirs, and the corresponding theoretical charts were drawn. In addition, an injection-production dynamic transient flow analysis model named "three points and two stages" suitable for an underground gas storage(UGS) well with alternate working conditions was proposed. The "three points" refer to three time points during cyclic injection and production, namely, the starting point of gas injection for UGS construction, the beginning and ending points of the injection-production analysis stage;and the "two stages" refer to historical flow stage and injection-production analysis stage. The study shows that the dimensionless pseudo-pressure and dimensionless pseudo-pressure integral curves of UGS well flex downward in the early stage of the injection and production process, and the dimensionless pseudo-pressure integral derivative curve is convex during the gas production period and concave during the gas injection period, and the curves under different flow histories have atypical features. The new method present in this paper can analyze transient flow of UGS accurately. The application of this method to typical wells in Hutubi gas storage shows that the new method can fit the pressure history accurately, and obtain reliable parameters and results.

Analysis of Ejector Cooling Flow

Now there were different aspects of heat exchangers of ejectors who could work in broad range of speed regulation characteristics, and with the different cores and auxiliary substance flows. For affirming of estimated performances the bench had been project, allowing to change speed regulation characteristics of a main stream and to regulate metering characteristics of an auxiliary fluid flow. For affirming of estimated performances of a heat exchanger of an ejector the imitative bench and with a view of accident prevention had been project, cooled air and the prepare water actuation mediums. The bench had been positioned in an insulated cooled room. For putting off gauging the multifunctional measuring complex of TESTO 400, was taken the temperature a surrounding medium, and a water rate does regulate by us. The high speed photo cameras were applied to bracing of formation of drips. Strain-gauge balances apply to determination of mass of water on the shield. The air flow was shape, and moving in an ejector heat exchanger by means of the axial multiple-speed fan. The purpose of projection of a heat interchanger of an ejector is maintaining of airspeeds by means of the ventilator in the mixing chamber 10 to 80 meters per second. The temperature of given air was a stationary value, equal to -20℃. Temperature of injection water was varying from 4 to 20℃.

基于FlowMIS平台的工程项目管理系统在燃气行业中的应用

探讨了依据燃气管理系统FlowMIS平台,相关体系结构和实施方法。

3-TIER数据库开发工具Visual DBTOOLS 3.0——Web Flow ERP强力功能

WORKFLOW(工作流程),应用在企业里,我们又称它为AUTOFLOW(企业自动化流程管理),在市场上流行至少3年了,初期大都用来解决企业文件流通与签核的问题,由于无法与MIS系统与ERP相互整合,所以近一年来,国际大厂纷纷标榜与ERP结合的WORK FLOW,这已经是现代应用软件的标准配备,也是企业信息化的必备功能.