Molecular dynamics study of the effect of external electric field amplitude and cavity on thermal properties of Ammonia/Copper Nano-Refrigerant.

• The Molecular Dynamics simulation method is implemented. • This study simulates ammonia refrigerant's atomic behavior with Cu nanoparticles in a nanochannel. • With increasing the external electric field amplitude to 5 Å, the heat flux values converge to 1395 W/m2. • The sample has a higher heat flux in the presence of a rectangular cubic atomic cavity. • Heat flux and aggregation time values for samples with rectangular cubic cavities are 1650 W/m2, 4.59 ns, respectively. With the ever-increasing energy costs, the need to improve the efficiency of cooling systems, reduce costs, and optimize the design is usually the first goal for system designers. One way to improve these systems is to use nano-refrigerants (NRs). This study simulates the thermal manner of ammonia refrigerant with Cu nanoparticles (NPs) in a nanochannel (NC) by calculating parameters such as velocity (V) and temperature (T) profiles, aggregation time (AT), and heat flux (HF). The result shows that by increasing the electric field amplitude (EFA) from 1 to 5 V/m, the maximum V and maximum T increase from 0.00086 Å/ps and 240 K to 0.00089 Å/ps and 245 K, respectively. With increasing the external EFA to 5 V/m, the HF value converges to 1395 W/m2, and the AT decreases to 3.90 ns. On the other hand, the change in maximum V in the samples with the pyramid, half-spherical (HS), and rectangular cubic (RC) cavities reached 0.74000 Å/ps, 0.00072 Å/ps, and 0.6565 Å/ps, respectively, and the maximum T changes to 232 K, 238 K, and 235 K in the RC, HS, and pyramid cavities samples. The results show that the structure has a higher HF in the presence of the RC cavity. So, the HF and AT values for samples with RC cavities are 1650 W/m2 and 4.59 ns, respectively. [ABSTRACT FROM AUTHOR]