Hussain Zakir, Hayat Tasawar, Alsaedi Ahmed, Anwar Muhammad Shoaib
Department of Mathematics, University of Baltistan, Skardu, 16100, Pakistan.
Department of Mathematics, Quaid-I-Azam University 45320, Islamabad, 44000, Pakistan.
Sci Rep. 2021 Nov 24;11(1):22838. doi: 10.1038/s41598-021-02228-9.
The addressed work explains SWCNTs (Single walled carbon nanotubnes) and MWCNTs (Multi walled carbon nanotubnes) nanofluid flow under the influences of temperature dependent viscosity and mixed convection. Comparative study of SWCNTs and MWCNTs suspended in base liquid is presented. Further heat and mass transfer are addressed for nanofluid effected by radiation, heat generation/absorption and diffusion species. Mathematical development of problem is taken in cylindrical coordinates. System of highly nonlinear differential equations are constructed via appropriate transformations. The system of equations are tackled numerically by bvp4c MATLAB solver. The findings of the study show that larger volume fraction [Formula: see text] contributes to enhance the nanoliquid flow. The velocity by submerging MWCNTs is noted higher than SWCNTs. Furthermore, the relationship between the viscosity variable [Formula: see text] and the temperature is such that the temperature near the surface decreases with increase in [Formula: see text], while at the same time the temperature away from the surface increases. Subsequently, higher temperature is observed in SWCNTs-liquid compared to the MWCNTs-liquid to the similar values of [Formula: see text]. Further, heat transfer is an increasing function of varying viscosity variable [Formula: see text].
上述工作解释了单壁碳纳米管(SWCNTs)和多壁碳纳米管(MWCNTs)纳米流体在温度依赖粘度和混合对流影响下的流动情况。文中给出了悬浮于基础液体中的SWCNTs和MWCNTs的对比研究。此外,还探讨了受辐射、热生成/吸收和扩散物质影响的纳米流体的传热传质问题。该问题的数学推导采用柱坐标。通过适当的变换构建了高度非线性微分方程组。利用MATLAB求解器bvp4c对方程组进行了数值求解。研究结果表明,较大的体积分数[公式:见原文]有助于增强纳米流体的流动。将MWCNTs浸入时的速度高于SWCNTs。此外,粘度变量[公式:见原文]与温度之间的关系是,表面附近的温度随[公式:见原文]的增加而降低,而同时远离表面的温度升高。随后,在[公式:见原文]值相似的情况下,观察到SWCNTs - 液体中的温度高于MWCNTs - 液体中的温度。此外,传热是粘度变量[公式:见原文]变化的增函数。