Abstract

In this paper, the numerical analysis of an impinging jet of Al2O3-water nanofluid in laminar and turbulent flow is carried out by using ANSYS. The main purpose of the paper is to describe the effects on heat transfer through a parametric analysis by varying jet-to-plate distance, volume fraction of nanoparticles and Reynolds number based on jet diameter. To assess how all these parameters affect the heat transfer performance, the area weighted average Nusselt number on the plate, its value at the stagnation point and the heat transfer uniformity have been considered as output parameters. They will give an idea of the goodness of the heat transfer mechanism. The results show a remarkable heat transfer enhancement when using nanofluids. Firstly, for laminar flow, the heat transfer is, as minimum, around 25% and 30% higher for the stagnation and averaged Nusselt numbers, respectively. Secondly, for turbulent flow, the heat transfer is, as minimum, around 20% higher for both the stagnation and averaged Nusselt numbers. However, the uniformity of the heat transfer gets worse when using nanofluids. Finally, some numerical correlations are given to predict the output parameters for the range of the input parameters.

摘要

本文利用ANSYS对Al2O3-水纳米流体在层流和湍流中的撞击射流进行数值分析。该论文的主要目的是通过改变射流到板的距离、纳米粒子的体积分数和基于射流直径的雷诺数，通过参数分析来描述对传热的影响。为了评估所有这些参数如何影响传热性能，板上面积加权平均努塞尔数、其在驻点处的值和传热均匀性已被视为输出参数。他们将了解传热机制的优点。结果表明，当使用纳米流体时，传热显着增强。首先，对于层流，传热最小，停滞数和平均努塞尔数分别高出约 25% 和 30%。其次，对于湍流，对于停滞数和平均努塞尔数，传热至少要高出约 20%。然而，当使用纳米流体时，传热的均匀性会变差。最后，给出了一些数值相关性来预测输入参数范围内的输出参数。