Novel Finite Element Method to Predict Blast Wave Transmission Through Human Ear

Abstract

As military weapons systems continue to become more powerful, the noise levels they generate become more dangerous to the soldiers deploying them. This has increased the need for advanced methods of evaluating the risks of weapon-generated pressure profiles as well as the need for advanced Hearing Protection Devices to protect against these profiles. The Finite Element Method in conjunction with Computational Fluid Dynamics may be employed in the proposed Human Ear Model to predict human ear response to high-intensity impulse pressures and give insight into earplug function. This thesis focuses on the development of the first Finite Element model of the human ear for blast impulse analysis. Real-ear geometry was adapted to generate strongly coupled Fluid-Structure Interaction analyses in Fluent/ANSYS Mechanical software. Pressure waveforms measured during human cadaver temporal bone experiments were applied to the model as input; the model was validated by comparing the predicted waveforms monitored at locations within the ear with experimental waveforms measured at identical locations. The model was then applied to explain trends observed during experimentation. A conceptual model was conceived to investigate the role of orifice geometry in nonlinear earplugs. Then, linear and nonlinear earplugs were introduced to the Human Ear Model for blast impulse analysis.