Traffic noise in big cities impacts the people who live and work in high-rise buildings alongside arterial roads. To determine this impact magnitude, this paper proposes and validates a microscopic level method that locally predicts the total noise level and the spectral characteristics of traffic flow in the near-road region. In the proposed method, the vehicles on the road are considered as multiple queues of moving point sound sources with ground reflection considered. To account for the flow of vehicles on the road, traffic field data, and individual vehicle noise source models are also employed. A field measurement is conducted to validate the proposed method. Results comparison shows that the predicted and the measured overall A-weighted sound pressure level and A-weighted noise spectra are within 3 dBA and 5 dBA, respectively. Based on the validated method, the spatial distribution of traffic noise near the arterial road is investigated for different traffic scenarios.

Accurate temperature prediction is vital for the canned permanent magnet synchronous motor (CPMSM) used in the vacuum pump, as it experiences severe heating. In this paper, a novel motor temperature calculation method is proposed, which takes into account the temperature impact on the heat transfer capacity. In contrast to existing electromagnetic-thermal coupled calculation methods, which solely address the temperature effect on the motor electromagnetic field, the proposed method comprehensively considers its impact on motor losses, permanent magnet magnetic properties, thermal conductivity, and heat dissipation ability of motor components, resulting in a motor temperature simulation that closely resembles the actual physical process. To verify the reliability of the proposed temperature calculation method, a 1.5 kW CPMSM was chosen as the research subject. The method was used to analyze the temperature distribution characteristics of the motor and assess the impact of ambient temperature on motor temperature rise. Furthermore, a prototype was fabricated, and an experimental platform was established to test the motor temperature. The results demonstrate good agreement between the calculated results obtained using the proposed method and the experimental data. This research not only provides a theoretical foundation for optimizing the design of the CPMSM but also provides valuable insights into its operational safety and reliability.