Perpustakaan Digital ITB

The use of electric cars has surged rapidly worldwide recently due to increased awareness among car manufacturers and the public about the threat of global warming caused by emissions from conventional vehicles. Although batteries play the most crucial role in electric cars, they also pose the greatest threat. With high energy density, batteries are prone to catching fire or even exploding if thermal runaway occurs. Thermal runaway can happen if the battery overheats. Moreover, impact loading can also trigger thermal runaway due to structural damage within the battery. Therefore, a battery protector against impact load for electric cars that is used also as heat dissipation is needed. In this research, auxetic structures are chosen due to its unique characteristic, i.e. negative Poisson's ratio (NPR), with a potential other use for heat dissipation. The aim of this study is to design a battery protector as a radiator by optimizing the dimensions of the auxetic structure. The design requirement of this research is the auxetic structure capable to decrease the battery coolant’s temperature from 37°C to 30°C with volumetric flowrate at 25.7 L/min. In this research, the optimization process was conducted analytically to achieve the highest heat transfer rate by varying the dimensions of ????1, ????2. The methodology conducted within this research are as follows, the initial step involves conducting a comprehensive literature study, followed by modelling and software validation. The validation process is conducted by comparing the result of temperature difference of regular fin heat exchanger from simulations in Ansys to theoretical calculations. The optimization is conducted analytically in MATLAB by simplifying the auxetic structure as a regular fin. After the dimensions are optimized, Revalidation must be conducted again to find the error of the simplification in the optimization process. In conclusion, the optimization results indicate that the optimal values are ????1 at 75°, ????2 at 45°. Consequently, the heat transfer rate q for 50 auxetic cells is 65.49 W. The number of auxetic cells needed to decrease 7°C coolant’s temperature is 10211 auxetic cells for 2 modules with a total weight of 13.4 kg.