Directional characteristics and acoustic efficiency of Tonpilz transducers: A FEM-based underwater study

The directional properties and acoustic efficiency of Tonpilz transducers are investigated in this work using finite element method (FEM) simulations. The acoustic pressure distribution showed distinct propagation patterns, and pressure uniformity increased by 17 % with optimized meshing. The sound pressure level (SPL) analysis revealed a 45 dB drop between the transducer head and the perfectly matched layer (PML), indicating >90 % absorption efficiency and effective wave damping. The 3D radiation pattern showed a shift from quasi-omnidirectional emission at 1 kHz to highly concentrated beams at 40 kHz, with beam width narrowing by 28 %. Polar beam sensitivity graphs demonstrated frequency-dependent directivity, with directional gain increasing by 22 % between 10 and 40 kHz. A comparison of interior and external fields revealed a 15 % increase in exterior SPL uniformity, demonstrating accurate field propagation. The Directivity Index (DI) analysis revealed a 30 % improvement in beam focusing when compared to piston models. Total radiated power increased by 18 % across the ideal frequency band following PML parameter tweaking. Overall, FEM-based modelling provides a predictive framework for improving Tonpilz transducer directivity, efficiency, and energy transfer, hence enabling enhanced sonar, marine communication, and stealth technologies.