11. Bioengineering and Bio-thermal Fluid Dynamics

Comprehending the olfactory capacities of sharks holds pivotal significance in unraveling their navigation and predation strategies. This interdisciplinary investigation harmonizes morphological analyses, computational fluid dynamics simulations, and flow visualization experiments to unravel the intricate interplay between shark morphology and olfactory proficiency, spotlighting the blue shark (Prionace glauca) as the primary subject of inquiry. Morphological investigations of shark heads and nasal cavities, utilizing specimens from Taiwanese fish markets, revealed associations between head shapes, nose locations, habitats, and diets. Computed tomography scans provided detailed insights into the three-dimensional structures, including the number, size, and spacing of lamellae within the nasal cavities. Computational fluid dynamics simulations and flow visualization experiments were conducted to examine the effects of head morphology on odorant transport. By releasing dyes at various upstream positions and mapping their trajectories, the detectable range by the shark was determined. Results underscored how head shapes influence the entry of odorants into the nasal chambers, affecting internal passages and travel times. Moreover, environmental flow rates significantly impacted odorant residence times and diffusion within the nasal cavities, shedding light on the role of flow dynamics in olfaction. The integration of 3D imaging data and computational fluid dynamics elucidated the interaction between external morphology, internal nasal cavity structure, and fluid dynamics in shark olfaction. The presence of independent olfactory chambers, complex internal structures, and head deflection angles emerged as significant factors influencing the olfactory mechanism in blue sharks. These findings not only deepen our understanding of shark sensory ecology but also have practical implications for applications such as underwater odor detection and environmental conservation.