Ramzan Muhammad, Mohammad Mutaz, Howari Fares, Chung Jae Dong
Department of Computer Science, Bahria University, 44000 Islamabad, Pakistan.
Department of Mechanical Engineering, Sejong University, Seoul 143-747, Korea.
Entropy (Basel). 2019 Jun 28;21(7):642. doi: 10.3390/e21070642.
Our objective in the present study is to scrutinize the flow of aqueous based nanofluid comprising single and multi-walled carbon nanotubes (CNTs) past a vertical cone encapsulated in a permeable medium with solutal stratification. Moreover, the novelty of the problem is raised by the inclusion of the gyrotactic microorganisms effect combined with entropy generation, chemical reaction, and thermal radiation. The coupled differential equations are attained from the partial differential equations with the help of the similarity transformation technique. The set of conservation equations supported by the associated boundary conditions are solved numerically with the bvp4c MATLAB function. The influence of numerous parameters on the allied distributions is scrutinized, and the fallouts are portrayed graphically in the analysis. The physical quantities of interest including the skin friction coefficient and the rate of heat and mass transfers are evaluated versus essential parameters, and their outcomes are demonstrated in tabulated form. For both types of CNTs, it is witnessed that the velocity of the fluid is decreased for larger values of the magnetic and suction parameters. Moreover, the value of the skin friction coefficient drops versus the augmented bioconvection Rayleigh number. To corroborate the authenticity of the presented model, the obtained results (under some constraints) are compared with an already published paper, and excellent harmony is achieved in this regard.
我们在本研究中的目标是仔细研究包含单壁和多壁碳纳米管（CNT）的水基纳米流体在渗透介质中通过垂直圆锥体时的流动情况，该渗透介质存在溶质分层。此外，通过纳入回转微生物效应、熵产生、化学反应和热辐射，该问题的新颖性得以提升。借助相似变换技术，从偏微分方程中得到耦合微分方程。由相关边界条件支持的守恒方程组使用MATLAB函数bvp4c进行数值求解。研究了众多参数对相关分布的影响，并在分析中以图形方式描绘了结果。对包括表面摩擦系数以及传热和传质速率在内的感兴趣的物理量相对于基本参数进行了评估，并以表格形式展示了它们的结果。对于两种类型的碳纳米管，都观察到对于较大的磁参数和抽吸参数值，流体速度会降低。此外，表面摩擦系数的值随着生物对流瑞利数的增加而下降。为了证实所提出模型的真实性，将所得结果（在某些约束条件下）与已发表的论文进行了比较，在这方面取得了很好的一致性。
