Two-Mode Fractal Radiator with Rotatable Fin Elements Based on a Modified Y-System

This study is devoted to a dual-mode fractal radiator with a modified topology. Its key feature is the ability to alter end-wall orientation via gear engagement between wall-mounted gears and discrete positioning wheels. The basic fractal structure derived from a Y system by replacing the initiator with a V initiator and imposing a conjugation condition on parallel daughter walls. This yields a natural topological feature: the parallel end walls of the final recursion level can rotate into regular polygonal face positions. The aim was to create a novel finning that combines fractal efficiency with configurational adaptability for optimizing heat transfer under varying conditions, and to evaluate its thermal performance via steady state modeling. Objectives included: developing a parametric fractal model incorporating conditions for the topological feature; designing a dual mode module with ro-tating elements; and engineering the rotation mechanism. Numerical simulations of steady conju-gate heat transfer were performed for open and closed configurations using full element models. Key results include: validation of the rotation mechanism design; confirmation that closed configuration walls act as reflectors, enhancing radiative heat transfer; and demonstration of thermal accumulator operation in the closed mode. The significance of the obtained results lies in the fact that a two-mode fractal radiator module with discrete transmission, allowing the fin topology to be changed, has been developed and analyzed. The proposed solution expands the capabilities of designing heat exchange systems, offering a solution suitable for local modernization of sections with variable oper-ating modes.