Sadia Haleema, Mustafa M
School of Natural Sciences (SNS), National University of Sciences and Technology (NUST), Islamabad, 44000, Pakistan.
Heliyon. 2023 Jul 26;9(8):e18683. doi: 10.1016/j.heliyon.2023.e18683. eCollection 2023 Aug.
Revolving-disk systems are employed in various industrial settings including turbine engineering, chemical and food processing industries and others. The current article scrutinizes a second-grade fluid motion generated by an infinite porous disk having partial slip character. Heat transfer induced by heating of the disk surface and by viscous and ohmic heating effects is modeled and analyzed under thermal slip condition. Accompanying mass transfer process with thermophoretic diffusion is also formulated. A self-similar system is obtained akin to the case of no-slip case discussed in a previously published study. The adoption of velocity slip assumption induces non-linearity in the boundary conditions in velocity components. Computational procedure embedded in MATLAB bvp4c platform is opted to simulate the system for full range of slip parameters. In contrast to a previously published work pertaining to the no-slip case, present numerical methodology gives accurate results for wide ranges of Prandtl number and elasticity parameter. Boundary layer formations above the disk are examined under various controlling parameters. A comparative assessment of slip and no-slip cases is presented through both graphical illustrations and tabulated results for the resisting torque, the Nusselt number and the Sherwood number. Current numerical findings match very well with the existing homotopy solutions for the no-slip case. The presence of a wall slip mechanism leads to a clear suppression of all the velocity components. Furthermore, an augmentation in the thermal/concentration slip coefficient significantly reduces the thermal/solutal penetration depth. Additionally, we observe a noticeable increase in the driving torque as the elasticity parameter enhances. The slip action of the surface is also predicted to raise the torque required by the disk.
旋转盘系统应用于各种工业环境,包括涡轮工程、化工和食品加工行业等。本文研究了具有部分滑移特性的无限大多孔盘产生的二阶流体运动。在热滑移条件下,对由盘表面加热以及粘性和欧姆加热效应引起的传热进行了建模和分析。还建立了伴有热泳扩散的传质过程。得到了一个类似于先前发表的研究中无滑移情况的自相似系统。速度滑移假设的采用在速度分量的边界条件中引入了非线性。选择MATLAB bvp4c平台中嵌入的计算程序来模拟整个滑移参数范围内的系统。与先前发表的关于无滑移情况的工作相比,目前的数值方法在广泛的普朗特数和弹性参数范围内给出了准确的结果。在各种控制参数下研究了盘上方的边界层形成。通过图形说明和表格结果对滑移和无滑移情况进行了比较评估,包括阻力矩、努塞尔数和舍伍德数。目前的数值结果与无滑移情况的现有同伦解非常吻合。壁面滑移机制的存在导致所有速度分量明显受到抑制。此外,热/浓度滑移系数的增加显著减小了热/溶质渗透深度。此外,我们观察到随着弹性参数的增加,驱动扭矩有明显增加。表面的滑移作用也预计会增加盘所需的扭矩。