当前位置: X-MOL 学术Heat Mass Transfer › 论文详情
Our official English website, www.x-mol.net, welcomes your feedback! (Note: you will need to create a separate account there.)
Multi-objective numerical optimum design of natural convection in different configurations of concentric horizontal annular pipes using different nanofluids
Heat and Mass Transfer ( IF 2.2 ) Pub Date : 2021-03-11 , DOI: 10.1007/s00231-021-03051-8
Amer Al-damook , Itimad D. J. Azzawi

Natural convection heat transfer within concentric annular pipes has many engineering applications such as in heat exchangers, electronic devices, the nuclear energy sector, aerospace and pipeline systems. Therefore, this investigative research includes three parts, with the first containing numerical simulation to study the natural convection heat transfer in a concentric annular horizontal pipe for six different geometries (Circular, Square, Diamond, Triangular, Rectangular, and Elliptic) using pure water. The results showed that the heat transfer rate of concentric elliptic and circular pipes is nearly 40% and 37% respectively greater than that of the other geometries. Once the optimum geometry had been adopted, two types of nanofluids (Al2O3-H2O and H2O-SiO3) were examined to investigate whether nanofluid has positive effects compared to pure water. For the Al2O3-H2O nanofluid with 0.5% volume fraction, the heat transfer coefficient was found to increase by as much as 6% compared to pure water, with a low pressure drop. Finally, in order to find a novel multi-objective optimisation process, the effect of inclination angle (θ) and aspect ratio (AR) was also examined to find the optimum design for the concentric annular pipe for maximum heat transfer rate and minimum pressure through the annular gap. The multi-objective optimum design detected the scope of enhancement in heat transfer with acceptable pressure inside the annular gap at AR = 8 and θ = 90o. Therefore, some useful guidelines on the influence of both geometrical and working fluid parameters on concentric annular pipe design can be derived from this research.



中文翻译:

不同纳米流体在同心卧式环形管不同构型下自然对流的多目标数值优化设计

同心环形管道内的自然对流传热具有许多工程应用,例如在热交换器,电子设备,核能领域,航空航天和管道系统中。因此,这项研究包括三个部分,第一部分包含数值模拟,以研究使用纯水对六种不同几何形状(圆形,正方形,菱形,三角形,矩形和椭圆形)的同心环形水平管道中的自然对流传热。结果表明,同心椭圆形和圆形管道的传热率分别比其他几何形状高近40%和37%。一旦采用了最佳几何形状,便会生成两种类型的纳米流体(Al 2 O 3 -H 2 O和H检查了2 O-SiO 3),以研究纳米流体与纯水相比是否具有积极作用。对于体积分数为0.5%的Al 2 O 3 -H 2 O纳米流体,发现传热系数与纯水相比增加了6%,并且压降较低。最后,为了找到新颖的多目标优化过程,倾角(θ)和纵横比(AR还检查了),以找到同心环形管的最佳设计,以实现最大的传热速率和最小的通过环形间隙的压力。多目标优化设计在AR  = 8和θ  = 90 o的情况下,以环形间隙内可接受的压力确定了传热增强的范围。因此,可以从这项研究中得出一些关于几何参数和工作流体参数对同心环形管道设计的影响的有用指南。

更新日期:2021-03-11
down
wechat
bug