Vasu B, Dubey Ankita, Bég O Anwar, Gorla Rama Subba Reddy
Department of Mathematics, Motilal Nehru National Institute of Technology Allahabad, Prayagraj, Uttar Pradesh, 211004, India.
Department of Mechanical and Aeronautical Engineering, School of Science, Engineering and Environment (SEE), Newton Building, Salford University, Manchester, M54WT, UK.
Comput Biol Med. 2020 Nov;126:104025. doi: 10.1016/j.compbiomed.2020.104025. Epub 2020 Oct 2.
Two-dimensional rheological laminar hemodynamics through a diseased tapered artery with a mild stenosis present is simulated theoretically and computationally. The effect of different metallic nanoparticles homogeneously suspended in the blood is considered, motivated by drug delivery (pharmacology) applications. The Eringen micropolar model has been discussed for hemorheological characteristics in the whole arterial region. The conservation equations for mass, linear momentum, angular momentum (micro-rotation), and energy and nanoparticle species are normalized by employing suitable non-dimensional variables. The transformed equations are solved numerically subject to physically appropriate boundary conditions using the finite element method with the variational formulation scheme available in the FreeFEM++ code. A good correlation is achieved between the FreeFEM++ computations and existing results. The effect of selected parameters (taper angle, Prandtl number, Womersley parameter, pulsatile constants, and volumetric concentration) on velocity, temperature, and micro-rotational (Eringen angular) velocity has been calculated for a stenosed arterial segment. Wall shear stress, volumetric flow rate, and hemodynamic impedance of blood flow are also computed. Colour contours and graphs are employed to visualize the simulated blood flow characteristics. It is observed that by increasing Prandtl number (Pr), the micro-rotational velocity decreases i.e., microelement (blood cell) spin is suppressed. Wall shear stress decreases with the increment in pulsatile parameters (B and e), whereas linear velocity increases with a decrement in these parameters. Furthermore, the velocity decreases in the tapered region with elevation in the Womersley parameter (α). The simulations are relevant to transport phenomena in pharmacology and nano-drug targeted delivery in hematology.
对存在轻度狭窄的病变锥形动脉内的二维层流流变血液动力学进行了理论和计算模拟。考虑到药物递送(药理学)应用,研究了均匀悬浮在血液中的不同金属纳米颗粒的影响。讨论了Eringen微极模型在整个动脉区域的血液流变学特性。通过采用合适的无量纲变量对质量、线性动量、角动量(微旋转)、能量和纳米颗粒种类的守恒方程进行了归一化。使用FreeFEM++代码中可用的变分公式方案,在物理上合适的边界条件下对变换后的方程进行数值求解。FreeFEM++计算结果与现有结果具有良好的相关性。计算了选定参数(锥角、普朗特数、沃默斯利参数、脉动常数和体积浓度)对狭窄动脉段的速度、温度和微旋转(Eringen角)速度的影响。还计算了壁面剪应力、体积流量和血流的血液动力学阻抗。采用彩色等高线和图表来可视化模拟的血流特性。观察到,随着普朗特数(Pr)的增加,微旋转速度降低,即微量元素(血细胞)的自旋受到抑制。壁面剪应力随着脉动参数(B和e)的增加而降低,而线性速度随着这些参数的减小而增加。此外,随着沃默斯利参数(α)的升高,锥形区域的速度降低。这些模拟与药理学中的传输现象以及血液学中的纳米药物靶向递送相关。