Department of Mathematics and Statistics, 66934Hazara University, Mansehra, Pakistan.
Sci Prog. 2023 Jan-Mar;106(1):368504221149798. doi: 10.1177/00368504221149798.
In numerous industrial procedures, the main concern of design engineers is ensuring adequate heat and mass transfer, such as in the heating and cooling practices of solar water heaters, geothermal systems, extrusion of metal, insulation of buildings, electronics, turbines, aerodynamics, electronics, paper manufacturing, and glass fiber production. The unsteady double-diffusive mixed convection flow of boundary layer nanofluids above a vertical region near stagnation point flow is developed and examined here. The Brownian motion and thermophoresis effects are incorporated by using Buongiorno's model. In the thermal energy equations, diffusion of regular and cross types is also used. By the use of the local similarity method along with suitable similarity transformations, nonlinear unsteady partial differential equations are converted to nonlinear ordinary differential equations and are numerically solved by the Keller-Box method. The investigation expresses that these profiles of solute concentration and nanoparticle concentration, temperature, and velocity in their boundary layers, respectively, depending on several parameters. A graphic analysis of all these parameters' possessions on nature's boundary layers is depicted. The highest rate of heat transfer is obtained with negligible thermophoresis effect. Furthermore, it is perceived that an increase in and results in a reduction in the reduced Sherwood number of nanoparticles, whereas addition results in an increase in the number. There is a reverse effect on the temperature field and layer thickness for heat generation. In the wake of the above-mentioned potential applications, the current study of fluid flow has been found to be very interesting and innovative in the analysis of the influence of Brownian motion and thermophoresis effects near stagnation point flow, which will further make revolutions in industrial fields. Moreover, Buongiorno's model predicts the characteristics of double-diffusive fluids in enhancing heat transfers. This investigation has been established as a result of the numerous industrial applications mentioned above.
在众多工业过程中，设计工程师主要关注的是确保充分的传热和传质，例如在太阳能热水器、地热系统、金属挤压、建筑物隔热、电子、涡轮机、空气动力学、电子、造纸和玻璃纤维生产中的加热和冷却实践中。本文研究了位于驻点附近的垂直区域上边界层纳米流体的非稳态双扩散混合对流流动。通过使用 Buongiorno 模型，考虑了布朗运动和热泳效应。在热能方程中，还使用了正则和交叉扩散。通过使用局部相似方法以及合适的相似变换，将非线性非定常偏微分方程转换为非线性常微分方程，并通过 Keller-Box 方法进行数值求解。研究表明，这些边界层中溶质浓度和纳米颗粒浓度、温度和速度的分布分别取决于几个参数。对所有这些参数对自然边界层的影响进行了图形分析。在忽略热泳效应的情况下，可以获得最高的传热速率。此外，研究发现增加和会导致纳米颗粒的无量纲舍伍德数减少，而增加会导致 增加。对于热生成的温度场和层厚度，存在相反的影响。在上述潜在应用的推动下，对驻点流动附近布朗运动和热泳效应影响的分析发现，目前的流体流动研究在工业领域将进一步引发变革，这是非常有趣和创新的。此外，Buongiorno 模型预测了双扩散流体在增强传热方面的特性。由于上述众多工业应用，进行了这项研究。
