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朗盛聚氨酯业务:站得更高,看得更远——暨采访朗盛聚氨酯系统负责人Markus Eckert博士
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《环球聚氨酯》 2018年第8期62-63,共2页
2017年4月,朗盛完成了对科聚亚的收购,这一项总价值达24亿欧元的交易,是朗盛历史上规模最大的一次收购。对朗盛而言,聚氨酯是一个全新的业务领域,该业务并入了朗盛组建的聚氨酯系统业务部,旗下产品包括热铸预聚物、特殊水性分散体和聚... 2017年4月,朗盛完成了对科聚亚的收购,这一项总价值达24亿欧元的交易,是朗盛历史上规模最大的一次收购。对朗盛而言,聚氨酯是一个全新的业务领域,该业务并入了朗盛组建的聚氨酯系统业务部,旗下产品包括热铸预聚物、特殊水性分散体和聚酯多元醇。这些产品主要应用于建筑、采矿、石油、天然气、体育器材与电子产品行业。 展开更多
关键词 聚氨酯轮胎 Markus eckert 负责人
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Making Business of a Revolutionary New Technology The Eckert-Mauchly Company, 1945-1951
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作者 Lars Heide 《History Research》 2012年第8期477-489,共13页
关键词 计算机技术 革命性 企业 美国宾夕法尼亚大学 商用电脑 数字积分器 离散变量 不确定性
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流经有热源多孔平板并伴有化学反应的传热传质混合对流MHD流动 被引量:4
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作者 J·祖额科 S·阿么德 《应用数学和力学》 CSCD 北大核心 2010年第10期1160-1171,共12页
对流经无限竖直多孔平板的不可压缩粘性导电流体,稳定的传热传质混合对流MHD流动问题,给出了精确解和数值解.假定均匀磁场横向作用于流动方向,考虑了感应磁场及其能量的粘性和磁性损耗.多孔平板有恒定的吸入速度并均匀地混入流动速度.... 对流经无限竖直多孔平板的不可压缩粘性导电流体,稳定的传热传质混合对流MHD流动问题,给出了精确解和数值解.假定均匀磁场横向作用于流动方向,考虑了感应磁场及其能量的粘性和磁性损耗.多孔平板有恒定的吸入速度并均匀地混入流动速度.用摄动技术和数值方法求解控制方程.得到了平板上速度场、温度场、感应磁场、表面摩擦力和传热率的分析表达式.相关参数取不同数值时,用图形表示出问题的数值结果.讨论了从平板到流体的Hartmann数、化学反应参数、磁场的Prandtl数,以及包括速度场、温度场、浓度场和感应磁场等其它参数的影响.可以发现,热源/汇或Eckert数的增大,极大地提高了流体的速度值.x-方向的感应磁场随着Hartmann数、磁场的Prandtl数、热源/汇和粘性耗散的增大而增大.但是,研究表明,随着破坏性化学反应(K>0)的增大,流动速度、流体温度和感应磁场将减小.对色谱分析系统和材料加工的磁场控制,该研究在热离子反应堆模型、电磁感应、磁流体动力学传输现象中得到了应用. 展开更多
关键词 MHD 摄动技术 网络模拟法 混合对流 eckert 感应磁场 粘性耗散 热源/汇
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Combined heat and mass transfer by mixed convection MHD flow along a porous plate with chemical reaction in presence of heat source 被引量:1
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作者 J.ZUECO S.AHMED 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI 2010年第10期1217-1230,共14页
An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass tra... An exact and a numerical solutions to the problem of a steady mixed convective MHD flow of an incompressible viscous electrically conducting fluid past an infinite vertical porous plate with combined heat and mass transfer are presented.A uniform magnetic field is assumed to be applied transversely to the direction of the flow with the consideration of the induced magnetic field with viscous and magnetic dissipations of energy.The porous plate is subjected to a constant suction velocity as well as a uniform mixed stream velocity.The governing equations are solved by the perturbation technique and a numerical method.The analytical expressions for the velocity field,the temperature field,the induced magnetic field,the skin-friction,and the rate of heat transfer at the plate are obtained.The numerical results are demonstrated graphically for various values of the parameters involved in the problem.The effects of the Hartmann number,the chemical reaction parameter,the magnetic Prandtl number,and the other parameters involved in the velocity field,the temperature field,the concentration field,and the induced magnetic field from the plate to the fluid are discussed.An increase in the heat source/sink or the Eckert number is found to strongly enhance the fluid velocity values.The induced magnetic field along the x-direction increases with the increase in the Hartmann number,the magnetic Prandtl number,the heat source/sink,and the viscous dissipation.It is found that the flow velocity,the fluid temperature,and the induced magnetic field decrease with the increase in the destructive chemical reaction.Applications of the study arise in the thermal plasma reactor modelling,the electromagnetic induction,the magnetohydrodynamic transport phenomena in chromatographic systems,and the magnetic field control of materials processing. 展开更多
关键词 MHD perturbation technique network simulation method eckert number mixed convection induced magnetic field viscous dissipation heat source/sink
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填料因子变化时散堆填料泛点气速数值算法 被引量:1
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作者 李喃 《化学工程》 CAS CSCD 北大核心 2017年第10期59-61,共3页
泛点气速是填料塔设计的重要参数,Eckert关联图为目前工程上运用较为广泛的泛点气速求取方法。文中基于散堆填料的Eckert关联图,在考虑泛点填料因子f随液体泛点喷淋密度Lf变化的条件下,提出了泛点气速uf的数值算法;推导出泛点气速uf... 泛点气速是填料塔设计的重要参数,Eckert关联图为目前工程上运用较为广泛的泛点气速求取方法。文中基于散堆填料的Eckert关联图,在考虑泛点填料因子f随液体泛点喷淋密度Lf变化的条件下,提出了泛点气速uf的数值算法;推导出泛点气速uf的表达式为一个高度非线性化方程,并给出了该方程的2种求解方法。同时举例计算了一个散堆填料的泛点气速,并和著名的塔器流体力学计算软件(WPTR)计算结果做了对比。结果表明:文中的计算结果和WPTR的结果完全吻合;所使用的方程求解方法 Aitken-Steffensen具有快速、稳定的收敛性,可用于散堆填料的泛点气速计算。 展开更多
关键词 泛点气速 eckert关联图 填料因子 非线性方程求解
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填料塔压降计算的新关联
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作者 孙兰义 李军 +1 位作者 朱大亮 金鑫 《化工进展》 EI CAS CSCD 北大核心 2007年第z1期81-83,共3页
对填料塔Eckert通用压降关联图及Strigle通用压降关联图进行了比较分析,并对Strigle通用压降关联图等压降曲线进行了回归,得到分段的关联式,编制了相应的计算软件,计算的最大误差为6.50%,平均误差为2.67%,计算结果可靠,可以满足工程设... 对填料塔Eckert通用压降关联图及Strigle通用压降关联图进行了比较分析,并对Strigle通用压降关联图等压降曲线进行了回归,得到分段的关联式,编制了相应的计算软件,计算的最大误差为6.50%,平均误差为2.67%,计算结果可靠,可以满足工程设计的要求. 展开更多
关键词 填料塔 压降 eckert通用压降关联图 Strigle通用压降关联图
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MHD Flow, and Heat Transfer with Effects of Buoyancy, Viscous and Joules Dissipation over a Nonlinear Vertical Stretching Porous Sheet with Partial Slip 被引量:1
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作者 M. Subhas Abel Kulkarni Anant Kumar R. Ravikumara 《Engineering(科研)》 2011年第3期285-291,共7页
In this paper, the problem of steady laminar two-dimensional boundary layer MHD flow and heat transfer of an incompressible viscous fluid with the presence of buoyancy force and viscous dissipation over an vertical no... In this paper, the problem of steady laminar two-dimensional boundary layer MHD flow and heat transfer of an incompressible viscous fluid with the presence of buoyancy force and viscous dissipation over an vertical nonlinear stretching sheet with partial slip is investigated numerically. Numerical solutions of the resulting nonlinear boundary value problem in the case when the sheet stretches with a velocity varying nonlinearly with the distance is carried out. The effects of for various values of suction parameter, magnetic parameter, Prandtl number, Eckert number, buoyancy parameter, nonlinear stretching parameter and slip parameter on flow and heat transfer characteristics is investigated. 展开更多
关键词 MHD NONLINEAR STRETCHING PARAMETER Joules DISSIPATION VISCOUS DISSIPATION eckert Number Slip PARAMETER
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Comment on the paper “Hydromagnetic thin film flow of Casson fluid in non-Darcy porous medium with Joule dissipation and Navier's partial slip”
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作者 I.POP 《Applied Mathematics and Mechanics(English Edition)》 SCIE EI CSCD 2018年第7期1057-1058,共2页
The present comment concerns some doubtful results included in the abovepaper.
关键词 local inertia parameter magnetic parameter eckert number
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MHD Free Convection Flow past an Inclined Stretching Sheet with Considering Viscous Dissipation and Radiation
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作者 Maruf Hasan Enamul Karim Abdus Samad 《Open Journal of Fluid Dynamics》 2017年第2期152-168,共17页
The present study concentrates on the analysis of MHD free convection flow past an inclined stretching sheet. The viscous dissipation and radiation effects are assumed in the heat equation. Approximation solutions hav... The present study concentrates on the analysis of MHD free convection flow past an inclined stretching sheet. The viscous dissipation and radiation effects are assumed in the heat equation. Approximation solutions have been derived for velocity, temperature, concentration, Nusselt number, skin friction and Sherwood number using Nachtsheim-Swigert shooting iteration technique along with the six-order Runge-Kutta iteration scheme. Graphs are plotted to find out the characteristics of different physical parameters. The variations of physical parameters on skin friction coefficient, Nusselt number and Sherwood number are displayed via table. 展开更多
关键词 VISCOUS DISSIPATION Magnetic Field SKIN FRICTION eckert Number
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1900 m^3/h氨气填料吸收塔工艺计算
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作者 黄娜 焦佳悦 +1 位作者 孙雨含 张秀琴 《清洗世界》 CAS 2019年第11期52-52,54,共2页
本文采用单塔逆流的流程设计处理含有3.5%氨气的1900 m^3/h的混合气的吸收填料塔。以清水作为吸收剂,用传质能力强的38mm聚氯乙烯阶梯环散装填料,在20,101.325k Pa条件下,利用Eckert通用关联图计算出塔径0.6 m及压降4414.5 Pa。由修正... 本文采用单塔逆流的流程设计处理含有3.5%氨气的1900 m^3/h的混合气的吸收填料塔。以清水作为吸收剂,用传质能力强的38mm聚氯乙烯阶梯环散装填料,在20,101.325k Pa条件下,利用Eckert通用关联图计算出塔径0.6 m及压降4414.5 Pa。由修正的恩田公式得出填料塔高度为3 m。 展开更多
关键词 聚氯乙烯 填料塔 eckert通用关联图 泛点气速
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埃克特参考温度法的气动加热系统研究 被引量:3
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作者 雷攀 齐蓉 董国创 《计算机测量与控制》 北大核心 2013年第1期146-148,154,共4页
飞行器在高速飞行过程中产生的气动加热会对飞行器结构的刚度特性产生影响,从而可能导致飞行器性能下降甚至结构破坏;进行地面模拟结构热试验对研究飞行器的热载荷、热防护等气动加热的诸多问题意义重大;文章研究马赫数为2~4的气动加... 飞行器在高速飞行过程中产生的气动加热会对飞行器结构的刚度特性产生影响,从而可能导致飞行器性能下降甚至结构破坏;进行地面模拟结构热试验对研究飞行器的热载荷、热防护等气动加热的诸多问题意义重大;文章研究马赫数为2~4的气动加热地面模拟系统的模型、系统结构及控制方法,采用埃克特参考温度法推算出给定热流,与反馈热流比较,实现对地面模拟结构热试验系统的闭环控制;文章还研究了系统模型的辨识方法,采用遗传算法寻优系统的PI参数,并进行了两温区的平板气动热试验,一号温区最大误差1.8%,二号温区最大误差2.7%。 展开更多
关键词 气动加热 埃克特参考温度 平板气动热试验 遗传算法参数寻优
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氯气处理单元氯气洗涤塔塔径的优化
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作者 徐华 吴崎兵 《中国氯碱》 CAS 2013年第1期25-27,共3页
统计了国内不同规模烧碱装置氯气洗涤塔的典型塔径,并运用埃克特关联图和经济气速等理论计算出合理的塔径范围。剖析了国内氯气洗涤塔塔径偏大的原因并对已建和在建装置提出了优化建议。
关键词 氯气处理 氯气洗涤塔 操作气速 埃克特关联图
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小流量下的转静系盘腔传热特征分析 被引量:4
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作者 林立 任静 蒋洪德 《工程热物理学报》 EI CAS CSCD 北大核心 2012年第7期1122-1126,共5页
在一些情况下,燃机透平中用于供给轮缘密封的气体流量要小于自由盘的夹带流量。本文采用气热耦合数值计算的方法,并结合轮盘一维导热模型,分析了小流量下(λ_t<0.22)转静腔室传热特点及其中关键的影响因素。研究结果表明,对于小流量... 在一些情况下,燃机透平中用于供给轮缘密封的气体流量要小于自由盘的夹带流量。本文采用气热耦合数值计算的方法,并结合轮盘一维导热模型,分析了小流量下(λ_t<0.22)转静腔室传热特点及其中关键的影响因素。研究结果表明,对于小流量下的转静系盘腔系统,可以根据盘面传热系数随冷气量的变化定义一个临界流量λ_(t,c),当冷气流量大于λ_(t,c)时,盘面传热系数随冷气量增加缓慢增大,近似等于自由盘状态;当冷气量小于λ_(t,c)时,盘面传热系数随冷气量减小而迅速减小。文中给出了一种估算动盘面传热系数随冷气量变化的方法。文章同时分析了转速对于轮盘传热(λ_(t,c)<λ_t<λ_(t,fd))的影响,当转速对应的Ecb等于Ecb,c时,轮盘的体平均温度最低。 展开更多
关键词 转静系盘腔 气热耦合 埃克特数 一维模型
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Heat transfer attributes of Al_(2)O_(3)-Fe_(3)O_(4)/H_(2)O hybrid nanofluid flow over a yawed cylinder 被引量:1
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作者 P.M.Patil H.F.Shankar 《Propulsion and Power Research》 SCIE 2022年第3期416-429,共14页
Flow over yawed and unyawed blunt bodies often occurs in various engineeringapplications. The fluid flow over a yawed cylinder explains the practical significance of subseaapplications such as transference control, se... Flow over yawed and unyawed blunt bodies often occurs in various engineeringapplications. The fluid flow over a yawed cylinder explains the practical significance of subseaapplications such as transference control, separating the boundary layer above submergedblocks, and suppressing recirculating bubbles. The current study uses viscous dissipation toanalyze the mixed convective hybrid nanofluid flow around a yawed cylinder. Unlike the stan-dard nanofluid model, which only considers one type of nanoparticle, this work considers thehybridization of two types of nanoparticles: alumina (Al_(2)O_(3)) and magnetite (Fe_(3)O_(4)). A modelwas developed to investigate the heat transport behaviour of a hybrid nanofluid while account-ing for the solid volume fraction. The flow problem is modelled in terms of highly nonlinearpartial differential equations (NPDEs) subject to the appropriate boundary conditions. Thenappropriate non-similar transformations were used to non-dimensionalize the governing equa-tions. Furthermore, the non-dimensional governing equations were solved using the finite dif-ference method (FDM) and the quasilinearisation technique. The effects of water andnanoparticle concentrations on the velocity and the temperature patterns were illustrated graph-ically. The hybrid nanofluid reduces the velocity distribution in the spanwise and chordwise di-rections while increasing the surface drag coefficient. The hybrid nanofluid’s fluid temperatureand energy transport strength was higher than the base fluid and nanofluid. Also, the temper-ature of the fluid rises as the energy transfer strength diminishes due to an increase in the Eckert number, which characterizes viscous dissipation. However, when the yaw angle increases in thechordwise and spanwise directions, so does the fluid’s velocity. The new outcomes werecompared to previously published research and were in good agreement. 展开更多
关键词 Yawed cylinder Mixed convection Hybrid nanofluid eckert number Finite difference method
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Numerical investigation of two-dimensional and axisymmetric unsteady flow between parallel plates
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作者 P.Raissi M.Shamlooei +1 位作者 S.M.Ebrahimzadeh Sepasgozar M.Ayani 《Propulsion and Power Research》 SCIE 2016年第4期318-325,共8页
In this study,heat and mass transfer in a viscous fluid which is squeezed between parallel plates Is investigated numerically using the fouith-order Runge-Kutta method.The numerical investigation is carried out for di... In this study,heat and mass transfer in a viscous fluid which is squeezed between parallel plates Is investigated numerically using the fouith-order Runge-Kutta method.The numerical investigation is carried out for different governing parameters namely;the squeeze number,Prandtl number,Eckert number,Schmidt number and the chemical reaction parameter.Results show that Nusselt number has direct relationship with Prandtl number and Eckert number but it has reverse relationship with the squeeze number.Also it can be found that Sherwood number increases as Schmidt number and chemical reaction parameter increases but it decreases with increases of the squeeze number. 展开更多
关键词 Squeezing flow Heat transfer Mass transfer Schmidt number eckert number Chemical reaction parameter
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