Experimental investigation of the effect of mechanical vibration and rotating magnetic field on the hydrothermal performance of water-Fe3O4 ferrofluid inside a rifled tube

Vibration can enhance the hydrothermal performance by disturbing the thermal boundary layer. Also, the magnetic field increases the ferrofluid mixing, thereby enhancing the heat transfer rate. In this study, an experimental analysis of ferrofluid flow inside a rifled tube under the vibration and rotational magnetic field (RMF) effects was conducted by considering different Reynolds numbers (Re), nanoparticle concentrations (phi), and rifled tube pitches (P). In the first stage, the effect of Re and phi on the hydrothermal performance of the system in the absence of the vibration and RMF was explored. In the second stage, the effect of vibration on the performance evaluation criterion (PEC) of the system was investigated. Finally, the RMF effect was considered. Based on the results, the system with P = 5 mm showed the highest PEC in all experiments. The highest PEC without the vibration and RMF effects was obtained as 1.62 for P = 5 mm and phi = 0% at Re = 2000. The highest PEC under the vibration effect (1.28) was also found for Re = 2000 but at phi of 2%, when the highest vibration acceleration (5 m/s2) was applied. Among the RMFs examined, the RMF with the counter clock-wise along with the counter clock-wise fluid flow inside the rifled tube resulted in the highest PEC of 1.62. RMF improved the PEC of the system from 1.28 to 1.62, corresponding to a 21.32% increase, under the vibration.

Automated summary

Vibration and magnetic field can enhance the hydrothermal performance by disturbing the thermal boundary layer and increasing the ferrofluid mixing. Experimental analysis was conducted to study the effects of vibration and rotational magnetic field (RMF) on ferrofluid flow inside a rifled tube. The results showed that the system with a pitch of 5 mm exhibited the highest performance evaluation criterion (PEC). Without vibration and RMF effects, the highest PEC was obtained at a pitch of 5 mm and nanoparticle concentration of 0% with a Reynolds number of 2000. Under vibration, the highest PEC of 1.28 was achieved at a Reynolds number of 2000 and nanoparticle concentration of 2% with the highest vibration acceleration of 5 m/s2. Among the RMFs examined, the counter clock-wise RMF with the counter clock-wise fluid flow resulted in the highest PEC of 1.62. RMF improved the PEC of the system by 21.32% under vibration.