Akhter Rowsanara, Ali Mohammad Mokaddes, Alim M A
Department of Computer Science and Engineering, University of Scholars, Dhaka, 1213, Bangladesh.
Department of Mathematics, Mawlana Bhashani Science and Technology University, Tangail, 1902, Bangladesh.
Heliyon. 2024 Jul 16;10(14):e34580. doi: 10.1016/j.heliyon.2024.e34580. eCollection 2024 Jul 30.
Mixed convective nanofluid flow has substantial importance in improvement of thermal performance, and thermal engineering to meet the global energy crisis. In this study, mixed convective nanofluid flow in a porous-wavy channel with an inner heated triangular obstacle under magnetic field effect is numerically examined. Nanofluid within the channel is heated and cooled from its bottom and top wavy-surfaces. A heated triangular cylinder is located at the centerline of the wavy-channel. Finite element method is utilized to solve the non-dimensional governing equations. The code is validated comparing present results with published numerical and experimental results. The response surface method is also implemented to analyze the obtained results and its sensitivity. The numerical results indicate that strength of flow velocity is accelerated with rising Reynolds number, Darcy numbers and inlet-outlet ports length but declined for Hartmann number and volume fraction. Heat transferring rate and heat transfer irreversibility are substantially increased for higher values of Reynolds number, inlet-outlet ports length, Darcy number and nanoparticle volume fraction but a reverse trend is occurred for magnetic field effect. The thermal performance is found significantly improved with simultaneous increment in Re, ϕ, Da and decrement in . Positive sensitivity is achieved for input factors Re, ϕ, Da in computing while negative sensitivity to . Heat transfer rate is found more sensitive to the impact of Re and ϕ compared to Da and . 45.59 % more heat transmission potentiality is developed for using AlO-HO nanofluid (vol.5 %) instead of using base fluid water. Heat transfer enhancement rate is decreased by 36.22 % due to impact of magnetic field strength. In addition, 84.12 % more heat transferring rate is recorded in presence of triangular obstacle. Moreover, irreversibility components are influenced significantly for the presence of heated triangular obstacle. Bejan number is also found declined for increasing physical parameters. The findings of this investigation may offer a guideline for finding experimental results to design high-performance convective heat exchangers.
混合对流纳米流体流动对于提高热性能以及应对全球能源危机的热工程具有重要意义。在本研究中，对磁场作用下具有内部加热三角形障碍物的多孔波浪形通道内的混合对流纳米流体流动进行了数值研究。通道内的纳米流体从其底部和顶部波浪形表面进行加热和冷却。一个加热的三角形圆柱体位于波浪形通道的中心线上。采用有限元方法求解无量纲控制方程。通过将当前结果与已发表的数值和实验结果进行比较来验证代码。还采用响应面方法来分析所得结果及其敏感性。数值结果表明，流速强度随着雷诺数、达西数和进出口端口长度的增加而加快，但随着哈特曼数和体积分数的增加而降低。对于较高的雷诺数、进出口端口长度、达西数和纳米颗粒体积分数，传热速率和传热不可逆性显著增加，但磁场效应呈现相反趋势。发现随着Re、ϕ、Da同时增加以及 减小，热性能显著提高。在计算 时，输入因子Re、ϕ、Da具有正敏感性，而对 具有负敏感性。与Da和 相比，传热速率对Re和ϕ的影响更敏感。使用AlO-HO纳米流体（体积分数5%）代替基础流体水可使热传输潜力提高45.59%。由于磁场强度的影响，传热增强率降低了36.22%。此外，在存在三角形障碍物的情况下，记录到的传热速率提高了84.12%。而且，加热三角形障碍物的存在对不可逆性分量有显著影响。随着物理参数的增加，贝扬数也下降。本研究结果可为寻找实验结果以设计高性能对流热交换器提供指导。
