摘要
采用微热偶式测温和测湿技术,分别对大直径水平旋转圆筒表面对流传热和传质特性进行了对比实验研究.实验数据验证了在圆筒表面对流传热和传质之间存在着良好的可类比性,即旋转对圆筒表面对流传热边界层温度场分布和局部努塞尔数的影响规律与旋转对传质边界层浓度场分布和局部舍伍得数的影响规律相似,但顺向侧和逆向侧之间存在着明显的差异;旋转对圆筒表面平均传热努塞尔数数和平均传质舍伍得数的影响规律也相似,都存在临界雷诺数.当旋转雷诺数小于或等于临界雷诺数时,平均努塞尔数和平均舍伍得数随旋转雷诺数的变化基本保持不变;当旋转雷诺数大于临界雷诺数时,平均努塞尔数和平均舍伍得数随旋转雷诺数的增大而增大.实验中还发现,由于传热和传质的边界层条件不同,热质交换共存时的临界雷诺数小于纯对流传热时的临界雷诺数.
Heat and mass transfer characteristics from a large diameter horizontal rotatin been investigated systemically by suing the temperature and concentration measurement The analogy between the convective heat and mass transfer is validated directly by the data. The results indicate that the effect of rotation on the temperature distribution and g cylinder has instruments. experimental local Nusselt number is similar to that on the concentration distribution and local Sherwood number, but there is a obvious difference between the downstream side and upstream side. There is a similar behavior between the variation of average Nusselt with rotational Reynolds number and the variation of average Sherwood number with rotational Reynolds number, i. e. , they both have a critical Reynolds number. When the rotational Reynolds number is lower than critical Reynolds number, the average number and the average Sherwood number are independent of rotational Reynolds number, when the rotational Reynolds number is larger than critical Reynolds number, the average Nusselt number and the average Sherwood number increase with increasing rotational Reynolds number. Because of the different conditions between the heat and mass transfer, the measured combined heat and mass transfer critical Reynolds number is lower than that of the pure heat transfer.
出处
《华中科技大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2007年第1期83-87,共5页
Journal of Huazhong University of Science and Technology(Natural Science Edition)
关键词
测温测湿技术
旋转圆筒
边界层
传热和传质特性
temperature and concentration measurement techniques
rotating cylinder
boundary layer
heat and mass transfer characteristics
作者简介
马洪亭（1964-），男，博士研究生；天津，天津大学环境科学与工程学院（300072）,E-mail：mht116@126．com
