Darcy-Forchheimer flow of MHD free convective CNTs Casson nanoliquid via a cosinusoidally fluctuating heated plate

This study explores the influence of carbon nanotubes (CNTs), spanwise cosinusoidally fluctuating thermal and mass diffusion on unsteady MHD free convective flow of Casson nanoliquid via an infinite hot vertical porous plate in a Darcy-Forchheimer porous medium. The overlapping grid multi-domain trivariate spectral collocation method is used to solve the non-dimensional equations. The impact of varying physical estimators on profiles alongside skin friction factor, rate of heat, and mass transport is contemplated. It was disclosed that the velocity and skin friction factors can be maximized via strong buoyancy forces and porous permeability but minimized through strong magnetic field and the Darcy–Forchheimer relation. The temperature and rate of heat transport can be increased by higher levels of heat generation, viscous dissipation, diffusion-thermo, and radiation absorption. Conversely, these factors can be minimized with higher thermal radiation. The introduction of activation energy and nonlinear chemically reactive species is responsible for the increase in species concentration and the rate of mass transport. The velocity and temperature are enhanced with increasing CNTs volume fraction, which leads to an increment in skin friction factor and thermal transport rate. Therefore, the suspension of CNTs in conventional fluids to control the coolant level in industrial apparatuses is absolutely practical.

本研究探讨了碳纳米管（CNTs）、展向余弦波动热质扩散对达西-福希海默多孔介质中无限长竖直热多孔平板附近卡森纳米流体的非定常磁流体自由对流流动的影响。研究采用重叠网格多域三元谱配置法求解无量纲方程，考察了不同物理参数对流动剖面以及壁面摩擦系数、传热速率与传质速率的影响。结果表明，强化浮升力与多孔渗透率可提升流体速度与壁面摩擦系数，而强磁场与达西-福希海默关系则会削弱上述参数。此外，更高的生热率、粘性耗散、扩散热效应与辐射吸收可提升流体温度与传热速率；反之，增强热辐射则会降低这些参数。引入活化能与非线性化学反应组分可提升组分浓度与传质速率。随着碳纳米管体积分数的增加，流体速度与温度均得到提升，进而使得壁面摩擦系数与热传输速率升高。因此，在传统流体中悬浮碳纳米管以调控工业装置中的冷却液水平，具备切实的工程实用性。