بررسی عددی نیروهای موثر بر سرعت‌نسبی و انتقال‌حرارت جابجایی ‌آزاد آرام نانوسیال در جعبه‌ابزار اپنفوم

رفتار حرارتی نانوسیال آلومینا-آب تحت تاثیر نیروهای مختلف بر روی سرعت‌نسبی در محفظه مربعی‌شکل دو ‌بعدی توسط حلگر توسعه یافته در کارابزار متن‌باز اپنفوم بررسی شده است. این نیروها که شامل اینرسی، انتشار ‌براونی، ترموفورسیس، دیفیوزوفورسیس، اثر مگنوس، زهکشی‌سیالات و گرانش می‌باشند مورد مطالعه قرار گرفته و مهم‌ترین آن‌ها به صورت پارامتpj وارد معادلات بقای مخلوط گردید. شبیه‌سازی با استفاده از الگوریتم پیمپل (سیمپل+پیزو) و تقریب بوزینسک بر روی جریان‌جابجاییآزاد و آرام انجام شده است. نتایج مربوط به روش‌های مختلف در نمودارهای عدد ناسلت–عدد رایلی ارائه شد. بررسی این نتایج بیانگر دقت بهتر حلگر ارائه شده در این مقاله است.

Numerical investigation of the effect of different forces on the relative velocity of nanofluid by developing a new solver in OpenFOAM

In this study the free convection heat transfer of a nanofluid, including water and nanoparticles suspended in a square cavity is simulated numerically for a laminar flow. Open source framework i.e. OpenFOAM was used to develop the equations and make changes in the desired terms such as relative velocity between the nanoparticles and the base fluid. To achieve the purpose of the research and to ensure the accuracy of the numerical algorithms used in this framework, at first the free convection inside the cavity was investigated using twophase mixture model and the results of the present study were compared with the results presented in the literature. Then, with the help of existing mathematical equations, important parameters in simulating the forces acting on nanoparticles in the free convection inside the cavity were studied and as a result, the forces that had a significant impact were selected as the most important and corrected relative velocity was entered in the continuity, momentum, heat transfer and continuity equation of the second phase (nanoparticles) as a parameter called JP. This simulation was performed using the PIMPLE algorithm (SIMPLE + PIZO). To consider free convection, nanofluid’s density changes with Boussinesq relationship. The mixture twophase model has used for modeling with higher speed and more accuracy and also effective thermophysical properties of nanofluid, related to JP parameter have been used in order to increase the accuracy of work. As a result, the effect of these forces on different conditions was investigated.