Peng Yeping, Alsagri Ali Sulaiman, Afrand Masoud, Moradi R
Shenzhen Key Laboratory of Electromagnetic Control, College of Mechatronics and Control Engineering, Shenzhen University Shenzhen 518060 China
Mechanical Engineering Department, College of Engineering - Unayzah, Qassim University Saudi Arabia
RSC Adv. 2019 Jul 17;9(39):22185-22197. doi: 10.1039/c9ra03286j.
The impact of an axial magnetic field on the heat transfer and nanofluid flow among two horizontal coaxial tubes in the presence of thermal radiation was considered in this study. The impact of viscous dissipation was also considered. The well-known KKL (Koo-Kleinsteuer-Li) model was applied to approximate the viscosity of the nanofluid and the effective thermal conductivity. Furthermore, proper transformations for the velocity and temperature were applied in this study to obtain a set of ODEs (ordinary differential equations) for basic equations governing the flow, heat and mass transfer. In addition, the 4th order Runge-Kutta (RK) numerical scheme was applied to solve the differential equations along with the associated boundary conditions. The impacts of different parameters, including Hartmann number, Reynolds number, radiation parameter and aspect ratio, on the heat transfer and flow features were studied. According to the results, the value of the Nusselt number increases with an increase in the radiation parameter, Hartmann number and aspect ratio and a decrease in the Reynolds number and Eckert number.
本研究考虑了轴向磁场对存在热辐射的两根水平同轴管之间传热和纳米流体流动的影响。还考虑了粘性耗散的影响。应用著名的KKL(Koo-Kleinsteuer-Li)模型来近似纳米流体的粘度和有效热导率。此外,本研究对速度和温度进行了适当变换,以获得一组用于控制流动、传热和传质基本方程的常微分方程(ODEs)。此外,应用四阶龙格-库塔(RK)数值格式来求解微分方程以及相关的边界条件。研究了包括哈特曼数、雷诺数、辐射参数和纵横比在内的不同参数对传热和流动特性的影响。结果表明,努塞尔数的值随着辐射参数、哈特曼数和纵横比的增加以及雷诺数和埃克特数的减小而增大。