Alade Ibrahim Olanrewaju, Abd Rahman Mohd Amiruddin, Bagudu Aliyu, Abbas Zulkifly, Yaakob Yazid, Saleh Tawfik A
Department of Physics, Faculty of Science, Universiti Putra Malaysia, 43400, UPM Serdang, Malaysia.
AiFi Technologies LLC, Abu Dhabi, United Arab Emirates.
Heliyon. 2019 Jun 26;5(6):e01882. doi: 10.1016/j.heliyon.2019.e01882. eCollection 2019 Jun.
The specific heat capacity of nanofluids is a fundamental thermophysical property that measures the heat storage capacity of the nanofluids. is usually determined through experimental measurement. As it is known, experimental procedures are characterised with some complexities, which include, the challenge of preparing stable nanofluids and relatively long periods to conduct experiments. So far, two correlations have been developed to estimate the The accuracies of these models are still subject to further improvement for many nanofluid compositions. This study presents a four-input support vector regression (SVR) model hybridized with a Bayesian algorithm to predict the specific heat capacity of metallic oxides/ethylene glycol-based nanofluids. The bayesian algorithm was used to obtain the optimum SVR hyperparameters. 189 experimental data collected from published literature was used for the model development. The proposed model exhibits low average absolute relative deviation (AARD) and a high correlation coefficient (r) of 0.40 and 99.53 %, respectively. In addition, we analysed the accuracies of the existing analytical models on the considered nanofluid compositions. The model based on the thermal equilibrium between the nanoparticles and base fluid (model II) show good agreement with experimental results while the model based on simple mixing rule (model I) overestimated the specific heat capacity of the nanofluids. To further validate the superiority of the proposed technique over the existing analytical models, we compared various statistical errors for the three models. The AARD for the BSVR, model II, and model I are 0.40, 0.82 and 4.97, respectively. This clearly shows that the model developed has much better prediction accuracy than existing models in predicting the specific heat capacity of metallic oxides/ethylene glycol-based nanofluids. We believe the presented model will be important in the design of nanofluid-based applications due to its improved accuracy.
纳米流体的比热容是一种基本的热物理性质,用于衡量纳米流体的储热能力。通常通过实验测量来确定。众所周知,实验过程具有一些复杂性,包括制备稳定纳米流体的挑战以及进行实验所需的较长时间。到目前为止,已经开发了两种关联式来估算比热容。对于许多纳米流体成分,这些模型的准确性仍有待进一步提高。本研究提出了一种与贝叶斯算法相结合的四输入支持向量回归(SVR)模型,用于预测金属氧化物/乙二醇基纳米流体的比热容。贝叶斯算法用于获得最优的SVR超参数。从已发表文献中收集的189个实验数据用于模型开发。所提出的模型分别具有低平均绝对相对偏差(AARD)和高相关系数(r),分别为0.40和99.53%。此外,我们分析了现有分析模型在所考虑的纳米流体成分上的准确性。基于纳米颗粒与基液之间热平衡的模型(模型II)与实验结果显示出良好的一致性,而基于简单混合规则的模型(模型I)高估了纳米流体的比热容。为了进一步验证所提出技术相对于现有分析模型的优越性,我们比较了这三个模型的各种统计误差。BSVR、模型II和模型I的AARD分别为0.40、0.82和4.97。这清楚地表明,所开发的模型在预测金属氧化物/乙二醇基纳米流体的比热容方面比现有模型具有更好的预测准确性。我们相信,由于其提高的准确性,所提出的模型在基于纳米流体的应用设计中将具有重要意义。