Evolutionary Design with Freedom and Rhythm for Heat Transfer, Strength, and Power Utilization

Abstract

The thesis combines fundamental studies on the evolution of design and performance in flow fields. The first study investigates the evolving architecture of a composite material with configurable inserts, comparing different shapes such as plates, forks, chains, and diamonds. The inserts, having higher thermal conductivity and lower elasticity than the base material, lead to better performance in thermal conductance and mechanical strength when distributed wisely. Next, the thesis explores tree-shaped flow in a dendritic heat exchanger, examining two flow architectures: parallel orifices and sequential slits. It provides theoretical and numerical analysis on the step-down ratio in the size of the orifices and channels, contributing key design principles for future dendritic heat exchanger systems. The third study broadens the design of heat transfer systems by varying both the fin and flow channel aspect ratios. This comprehensive approach allows for predicting the complete design of high-density heat transfer architectures, providing higher heat transfer rates and lower pumping power. The fourth study is about periodic in-and-out airflow through a single orifice into an enclosure to refresh air quality. Two scenarios of airflow rhythm are analyzed, with findings indicating the optimal time intervals for maximum air replacement and minimal energy expenditure. The fifth study explores animal locomotion and the rhythm of propulsion in frogs and swimmers. The cyclic nature of work and energy dissipation is analyzed, revealing that evolutionary changes in body design and locomotion rhythm enhance power utilization and speed. Together, these studies highlight the role of evolving design principles in optimizing both natural and engineered systems, demonstrating how freedom in configuration and design leads to improved performance across a variety of applications.