Thermal performance of a pulsating heat pipe charged with $${{\varvec{F}}{\varvec{e}}}_{3}{{\varvec{O}}}_{4}$$-MWCNTs/DI water hybrid nanofluid: Experimental study and optimization

• Published in: Journal of thermal analysis and calorimetry 2022-12, Vol.147 (23), p.13535-13550
• Main Authors: Alishiri, Mojgan, Akbari, Ali, Saidi, Mohammad Hassan
• Format: Article
• Language: English
• Subjects: Electric properties; Nanotubes
• ISSN: 1388-6150; 1588-2926
• DOI: 10.1007/s10973-022-11517-y

In this study, we have employed a strategy for the optimization of the concentrations of iron oxide ( [Formula omitted])-multi-walled carbon nanotubes (MWCNTs)/deionized (DI) water hybrid nanofluid based on non-dominated sorting genetic algorithm-II (NSGA-II) before examining it inside the pulsating heat pipe (PHP), taking into account the basic criteria for PHP performance optimization. The thermophysical properties of the hybrid fluid were optimized to obtain concentrations with the highest thermal conductivity and specific heat capacity and the lowest dynamic viscosity and density. Also, the thermal performance of the PHP charged with the optimized concentrations of the hybrid nanofluid was tested. Results showed that the hybrid nanofluid containing [Formula omitted] [Formula omitted] of [Formula omitted] and [Formula omitted] [Formula omitted] of MWCNTs provides the best thermal performance for the PHP. Further, the thermal performance of the PHP with base fluid (DI water) was tested. The observations indicated a better start-up and a lower thermal resistance of the PHP with DI water. The thermal resistance of the PHP charged with mentioned hybrid nanofluid and DI water at a heat input of [Formula omitted] is [Formula omitted], which is almost [Formula omitted] lower than that of PHP charged with other hybrid nanofluids. Therefore, it can be concluded that although the [Formula omitted]-MWCNTs/DI water hybrid nanofluid has a relatively high thermal conductivity, its high viscosity, low specific heat capacity, and sedimentation of the nanoparticles deteriorate the thermal performance of the PHP compared to the base fluid due to increased concentration.