Flow-structure interaction simulation of a sei whale larynx

Airflow within the respiratory system is considered the sound source of the vocalization of baleen whales. While the U-fold in the baleen whale larynx has been suggested as a mammal vocal fold homolog, the sound production mechanism is still not clear. In the current study, thanks to a rare opportunity of obtaining a sei whale larynx, we use a numerical approach to explore the sound production mechanism in baleen whales. In our simulations, the realistic geometries of the sei whale laryngeal components, including the U-fold, the related cartilages, the respiratory tract, and the laryngeal sac, will be reconstructed from CT scans. The flow-structure interactions between the airflow and U-fold tissues will be simulated by using a coupled sharp-interface-immersed-boundary method based incompressible flow solver and finite element based solid mechanics solver. High-fidelity results of 3D vibrations of the U-fold tissues and airflow dynamics in both ingressive and egressive flow conditions will be obtained. Comparison with experimental measurements will be provided. This study will improve the fundamental understanding of the basic sound production mechanism and the possible sound control approaches in baleen whales.