Design and performance optimization of a bionic fish scale composite rib tube for efficient heat exchange

In aerospace and electronics cooling, compact heat exchangers often require high thermal efficiency with minimal flow resistance. The study addresses this specific challenge by exploring enhanced heat transfer in tube-side flows under strict pressure drop constraints. A novel bionic fish scale composite ribs tube (BFSCRT) is proposed and investigated using three-dimensional computational fluid dynamics simulations for turbulent flow (11,225 ≤ Re ≤ 33,675). A systematic parametric analysis is conducted to evaluate the thermo-hydraulic performance. Detailed comparisons of flow fields—including velocity streamlines, turbulent kinetic energy, and vorticity—are made among a plain tube (PT), a bionic fish scale tube (BFST), and the proposed BFSCRT. The results demonstrate that the composite structure effectively disrupts the thermal boundary layer and generates secondary flows without causing excessive flow resistance. The optimal configuration (with rib bottom b =0.4 mm and height h =0.6 mm) achieves a performance evaluation criterion value of 1.326, indicating a significant net performance gain. This case provides a concrete design solution and performance data for engineers seeking to improve thermal efficiency in systems with constrained pumping power.