Radiated noise analysis and optimization of integrated water tank for electric vehicles

Noise performance is a critical indicator of electric vehicles quality. This study aims to reduce the vibration noise of integrated water tank in an electric vehicle. The noise issue of integrated water tank filled with coolant is investigated and optimized using a combination of numerical simulations and experiments. Results show that the modal frequency of water tank decreases when the additional weight of coolant is considered, compared to the state without coolant. Analysis of acoustic response, acoustic transfer vector, and acoustic contribution shows that the sound pressure level at each field point peaks at 1268 Hz. The right side region exhibits strong sound pressure transfer capability, making it the hotspot for noise transfer. Therefore, the right side wall is the target optimization region for noise reduction. According to the Box-Behnken design, optimal noise reduction is achieved with a honeycomb length of 12 mm, height of 6 mm, and thickness of 1.5 mm. Sound pressure level and weight are reduced by 7.64% and 4.04 g, respectively. This study provides a scientific basis and technical support for controlling vibration noise in the integrated water tank of electric vehicle thermal management systems.