Optimization of the cold‐side heat exchanger design to improve the performance of the motorcycle exhaust thermoelectric generator

This study optimizes the main parameters of the cold‐side heat exchanger (CHE) longitudinal fin, including fin quantity ( N f ), fin thickness ( T f ), and fin height ( H f ), to enhance the performance of motorcycle exhaust thermoelectric generator units (TGUs) utilizing the computational fluid dynamics approach. The investigation shows that these parameters significantly affect the dissipation area of the CHE heat and the outside air velocity distribution in fin gaps, resulting in the fluctuation of TGU output power. The output power increases with respect to H f ; nevertheless, it first increases as N f and T f increase but decreases dramatically when N f or T f becomes too large. Besides, H f significantly affects output power, and its impact is almost independent of T f and N f , and vice versa; meanwhile, T f and N f have a strong relation. This study proposes two H f of 40 and 60 mm along with the optimal T f of 1 mm and N f of 29, providing significantly high output power, low weight, and compact size for TGU. This work contributes insight into the effect of CHE parameters on the TGU performance, and it is a crucial case study for selecting suitable heat sink parameters for TGU, considering practical requirements and conditions.