A molecular dynamic simulation of the influence of linear aggregations on heat flux direction on the thermal conductivity of nanofluids

• Published in: Powder technology 2023-01, Vol.413, p.118052, Article 118052
• Main Authors: Chen, Wenzhe, Zhai, Yuling, Guo, Wenjie, Shen, Xin, Wang, Hua
• Format: Article
• Language: English
• Subjects: Aggregations state; Included angle; Nanofluids; Nanoparticles size arrangement; Thermal conductivity
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2022.118052

To reveal abnormal enhancement of thermal conductivity of nanofluids, molecular dynamics simulation is employed to investigate effects of included angle and nanoparticles size arrangement on thermal conductivity of Cu/Ar nanofluids. Included angle θ ranged from 0 to 90°, and six types of size arrangements are designed using combinations of r1 and r2 of Cu nanoparticles of 11 Å and 8.48 Å, 10.5 Å and 9.45 Å. Results demonstrated by reducing θ from 90° to 0°, thermal conductivity improved from 0.165 to 0.184 W.m−1·K−1 as actual heat flux distance increasing. Moreover, larger Cu nanoparticles on either side attracted more Ar atoms to form a denser interfacial layer, creating a compact heat flux channel to transfer more heat. The optimum thermal conductivity is at θ = 0° and Type 1 (two larger Cu radius r1 = 10.5 Å on either side and two smaller radius r2 = 9.45 Å in the middle). [Display omitted] •Abnormal enhancement of thermal conductivity was revealed from microscopic view.•Effect of included angle of linear aggregations on thermal conductivity was conducted.•Particle size arrangement on thermal conductivity was comparatively investigated.•Optimum thermal conductivity was obtained to guide design of nanofluids.