Thermal and electrical analysis of batteries in electric aircraft using nanofluids

Batteries are the primary power supply for hybrid electric aircraft. The most important parameter affecting the performance, life, safety and cost of the batteries is the operating temperature. Therefore, thermal management of batteries is extremely important. The battery module (10 S, 3 P) consists of thirty prismatic lithium-ion batteries. The cooling of the battery is provided by nanofluid, which is a combination of nanoparticles and refrigerants in different mixing ratios (H2O + 3% Fe2O3, H2O + 4% Fe2O3, H2O + 6% Fe2O3), engine oil (EO + 3% Fe2O3, EO + 4% Fe2O3, EO + 6% Fe2O3). The temperatures of each of the batteries in the module are examined separately. The thermal and electrical studies of the battery model are also investigated with the volumetric ratio of the nanofluid, different input speeds and different discharge rates of the battery model. The busbar, which should not be ignored in the thermal management of the batteries, that is, the materials connecting the batteries to each other are included in the model. Air cooling, which is the traditional cooling method of the battery model, cannot bring the battery to the desired temperature range. For this reason, nanofluid cooling should be preferred. Considering the sensitivity to the volume fraction ratio, EO reacted more quickly than water. When the volume fraction ratio was increased from 3% to 6%, when the refrigerant was water, the temperature of the battery model changed by 0.05 K, and when the refrigerant was EO, there was a change of 1.15 K. Looking at all the results, they gave better results than the nanofluid EO added to the water. Considering the effect of the inlet velocity of the refrigerant on the maximum and minimum temperatures, there was a 1 K change at the maximum temperature, and a 0.2 K change at the minimum temperature (H20 + 6% Fe2O3).

Automated summary

Batteries are crucial for hybrid electric aircraft and their operating temperature greatly affects their performance and lifespan. Therefore, effective thermal management is vital. This study investigates the cooling of a battery module using nanofluids comprising nanoparticles and refrigerants at different ratios. The research also examines the impact of nanofluid volume ratio, input speeds, and discharge rates on the battery's thermal and electrical properties. Additionally, the study includes the consideration of busbars, which connect the batteries and play a role in thermal management. The results indicate that nanofluid cooling is more effective than air cooling, with different effectiveness observed depending on the type of refrigerant used. Moreover, the inlet velocity of the nanofluid affects the temperature range of the battery module.