期刊文献+
共找到6篇文章
< 1 >
每页显示 20 50 100
低温海水外掠圆管混合对流传热规律实验 被引量:1
1
作者 林日亿 李晓辰 +2 位作者 梁金国 徐伟栋 郭彬 《中国石油大学学报(自然科学版)》 EI CAS CSCD 北大核心 2018年第6期133-138,共6页
以自然海水为工质,对层流范围内低温海水的混合对流传热特性进行实验研究,研究换热特性与雷诺数、格拉晓夫数和管径的关系,并与经验公式进行对比;提出适用于层流范围内低温海水外掠圆管流动与换热系数的经验公式。结果表明,在实验范围... 以自然海水为工质,对层流范围内低温海水的混合对流传热特性进行实验研究,研究换热特性与雷诺数、格拉晓夫数和管径的关系,并与经验公式进行对比;提出适用于层流范围内低温海水外掠圆管流动与换热系数的经验公式。结果表明,在实验范围内努赛尔数随着雷诺数和格拉晓夫数增大而增大,且雷诺数越小,格拉晓夫数对努赛尔数的影响越明显;努赛尔数随着立管直径增大逐渐减小,小管径有利于增强对流传热强度;自然对流的影响随着雷诺数增加而减小,随着格拉晓夫数增大而增大;立管直径越大,自然对流对于总换热量的影响越强,且雷诺数越小,管径变化对自然对流在总换热量中的影响越明显。 展开更多
关键词 石油 传热 流动 低温海水 混合对流传热 实验
下载PDF
多进出口空间混合对流传热的数值分析 被引量:1
2
作者 邱霖 何杰 《华南理工大学学报(自然科学版)》 EI CAS CSCD 北大核心 1997年第6期97-103,共7页
采用原始变量,等间距的交错网格等方法对多进出口空间混合对流传热问题进行数值分析。通过对不同几何模型和边界条件在较宽的参数范围内进行计算,从而总结出混合对流传热的一般规律。
关键词 混合对流传热 原始变量法 层流
下载PDF
竖直圆管内超临界流体混合对流传热特性理论分析
3
作者 刘生晖 黄彦平 +4 位作者 刘光旭 王俊峰 昝元锋 郎雪梅 黄军 《原子能科学技术》 EI CAS CSCD 北大核心 2016年第12期2181-2187,共7页
理论推导了变密度引起的浮升力效应和流动加速效应对超临界流体混合对流传热特性的影响。结果表明,浮升力效应和流动加速效应通过改变壁面边界层外缘的切应力影响湍流对传热传质的贡献,进而改变超临界流体混合对流传热特性。浮升力效应... 理论推导了变密度引起的浮升力效应和流动加速效应对超临界流体混合对流传热特性的影响。结果表明,浮升力效应和流动加速效应通过改变壁面边界层外缘的切应力影响湍流对传热传质的贡献,进而改变超临界流体混合对流传热特性。浮升力效应通常在加热区域入口及上游区域表现明显,而流动加速效应在主流区流体温度达到拟临界温度时更显著。与实验研究结果对比发现,新建立的浮升力因子和流动加速因子可较好地预测竖直圆管内超临界流体混合对流条件下拟临界区域的局部传热特性。 展开更多
关键词 超临界二氧化碳 混合对流传热 浮升力效应 流动加速效应 拟临界区
下载PDF
Passive heat transfer enhancement of laminar mixed convection flow in a vertical dimpled tube 被引量:3
4
作者 M.TOOFANI SHAHRAKI A.LAVAJOO A.BEHZADMEHR 《Journal of Central South University》 SCIE EI CAS CSCD 2021年第11期3477-3490,共14页
Heat transfer enhancement in vertical tubes plays an important role on the thermal performance of many heat exchangers and thermal devices.In this work,laminar mixed convection of airflow in a vertical dimpled tube wa... Heat transfer enhancement in vertical tubes plays an important role on the thermal performance of many heat exchangers and thermal devices.In this work,laminar mixed convection of airflow in a vertical dimpled tube was numerically investigated.Three-dimensional elliptical governing equations were solved using the finite-volume technique.For a given dimpled pitch,the effects of three different dimple heights(h/D=0.013,0.027,0.037) have been studied at different Richardson numbers(0.1,1.0 and 1.5).The generated vortex in the vicinity of the dimple destructs the thermal boundary layer and enhances the heat transfer.Therefore,lower wall temperature is seen where the dimples are located.Fluid flow velocity at the near-wall region significantly increases because of buoyancy forces with the increase of Richardson numbers.Such an acceleration at the near-wall region makes the dimples more effective at higher Richardson number.Using a dimpled tube enhances the heat transfer coefficient.However,the pressure drop is not important.For instance,in the case of Ri=1.5 and h/D=0.037,20% gains in the heat transfer enhancement only costs2.5% in the pressure loss.In general,it is recommended using a dimpled tube where the effects of buoyancy forces are important. 展开更多
关键词 dimpled tube laminar mixed convection vertical tube heat transfer enhancement
下载PDF
Mixed convective heat and mass transfer analysis for peristaltic transport in an asymmetric channel with Soret and Dufour effects 被引量:5
5
作者 F.M.Abbasi A.Alsaedi T.Hayat 《Journal of Central South University》 SCIE EI CAS 2014年第12期4585-4591,共7页
The present investigation addresses the simultaneous effects of heat and mass transfer in the mixed convection peristaltic flow of viscous fluid in an asymmetric channel. The channel walls exhibit the convective bound... The present investigation addresses the simultaneous effects of heat and mass transfer in the mixed convection peristaltic flow of viscous fluid in an asymmetric channel. The channel walls exhibit the convective boundary conditions. In addition, the effects due to Soret and Dufour are taken into consideration. Resulting problems are solved for the series solutions. Numerical values of heat and mass transfer rates are displayed and studied. Results indicate that the concentration and temperature of the fluid increase whereas the mass transfer rate at the wall decreases with increase of the mass transfer Biot number. Furthermore, it is observed that the temperature decreases with the increase of the heat transfer Biot number. 展开更多
关键词 peristaltic transport heat and mass transfer Soret and Dufour effects convective boundary conditions
下载PDF
Novel Optimization Approach to Mixing Process Intensification
6
作者 郭凯 刘伯潭 +1 位作者 李奇 刘春江 《Transactions of Tianjin University》 EI CAS 2015年第1期1-10,共10页
An approach was presented to intensify the mixing process. Firstly, a novel concept, the dissipation of mass transfer ability(DMA) associated with convective mass transfer, was defined via an analogy to the heat-work ... An approach was presented to intensify the mixing process. Firstly, a novel concept, the dissipation of mass transfer ability(DMA) associated with convective mass transfer, was defined via an analogy to the heat-work conversion. Accordingly, the focus on mass transfer enhancement can be shifted to seek the extremum of the DMA of the system. To this end, an optimization principle was proposed. A mathematical model was then developed to formulate the optimization into a variational problem. Subsequently, the intensification of the mixing process for a gas mixture in a micro-tube was provided to demonstrate the proposed principle. In the demonstration example, an optimized velocity field was obtained in which the mixing ability was improved, i.e., the mixing process should be intensified by adjusting the velocity field in related equipment. Therefore, a specific procedure was provided to produce a mixer with geometric irregularities associated with an ideal velocity. 展开更多
关键词 convective mass transfer mass transfer ability flow pattern optimization calculus of variations porous media model
下载PDF
上一页 1 下一页 到第
使用帮助 返回顶部