The effects of different nanoparticles on physical and thermal properties of water in a copper oscillating heat pipe via molecular dynamics simulation

Background: Oscillating heat pipes (OHP) are equipment for heat transfer (HT) with a high heat transfer capacity which transfer heat from a heat source to a heat sink. One of the most significant factors affecting the performance of the heat pipes is the operating fluid contained inside them. Nanofluids (NFs), the fluids containing nanoparticles (NP), improve the thermal conductivity (TC), and HT over the base fluid. Methods: This study investigated the physical and thermal properties behaviors of water and Fe-Fe2O3-Fe3O4/ water NFs in an OHP with copper (Cu) walls. In this approach, the molecular dynamics (MD) simulation was used. The current simulation was performed using LAMMPS software. By solving Newton's equation of motion, the trajectories of particles were simulated over time. Significant findings: After 10 ns, the numerical value of heat flux (HF) in the presence of water converged to 1354 W/m2. The maximum numerical density of simulated Fe-Fe2O3-Fe3O4/water NF in the OHP reached 0.016 atom/ A3, 0.021 atom/A 3, and 0.022 atom/A3 values, respectively. The numerical maximum velocity of simulated FeFe2O3-Fe3O4 water NF in the OHP converged to 0.057 A/ps, 0.051 A/ps, and 0.044 A/ps, respectively. The numerical maximum temperature of simulated Fe-Fe2O3-Fe3O4 /water NF in the OHP was 522.68 K, 483.48 K, and 452.77 K, respectively. The numerical values of HF of simulated Fe-Fe2O3-Fe3O4/water NF in the OHP increased by 1462 W/m2, 1505 W/m2, and 1561 W/m2, respectively. Finally, the above studies expect an optimal mechanism for HT in the practical applications to be provided.

Automated summary

This study investigates the physical and thermal properties behaviors of water and Fe-Fe2O3-Fe3O4/ water nanofluids in an oscillating heat pipe. The results show that the addition of nanofluids improves heat flux, density, velocity, and temperature. These findings provide an optimal mechanism for heat transfer in practical applications.