COMSOL Model for an Enclosed Coaxial Carbon Nanotube Speaker

Carbon nanotube speakers are thin-film solid state speakers that operate on the principle of thermoacoustics. The speakers contain no moving parts and produce sound due to rapid oscillations in the surface temperature of the CNT film that creates pressure waves in the surrounding medium. CNT speakers are lightweight, cheap and have high operating temperature. An enclosed coaxial speaker was manufactured for automotive exhaust noise cancellation. The primary purpose of the speaker was to perform active cancellation of exhaust noise. This paper studies the COMSOL Multiphysics model for the coaxial speaker. The model is used to simulate the output sound pressure level of the speaker for different power levels. The temperature profile of the speaker and its efficiency is also studied using the model. The simulation results are verified by experimental testing. In addition to this, the performance of the speaker in different mediums is also discussed with respect to input power, output sound pressure level and efficiency. The model will be used to predict the behavior of the coaxial speaker for future designs and for different platforms and operating conditions.