The demand for 3D printer technology and products, one of the additive manufacturing methods, is increasing daily in the sectoral and academic fields. Many types of polymer-based filaments are used in 3D printers, pure or filled/reinforcement. Utilizing these specialized materials in places suitable for their mechanical and thermal properties will help efficiently use resources. Using 3D printers, it is possible to manufacture products that provide thermal insulation or good heat conduction in heating and cooling areas. Especially due to the energy requirements for heating and cooling, it is very important to know the thermal performance of materials to ensure and maintain energy efficiency. This study experimentally investigated the mechanical properties and heat conduction coefficients of 3D printed parts. The experiments were conducted with seven different filament materials (PLA, PLA+, PLA-CF, PLA Wood, Tough PLA, ABS+, TPU) and three layer thicknesses (0.1, 0.2, and 0.3 mm). Samples for tensile testing, hardness, and thermal conductivity coefficient measurements were produced, and measurements were performed. In the experiments, the highest tensile strength was obtained in PLA-CF with 0.3 mm layer thickness, and the lowest tensile strength was obtained in PLA Wood with 0.3 mm layer thickness. Tensile strength decreased with an increasing layer thickness in PLA, PLA Wood, ABS+, and TPU, while it increased in PLA-CF. The highest tensile strength of PLA+ was determined to be 0.2 mm and 0.1 mm layer thickness in Tough PLA. Hardness results showed minimal change in hardness values with increasing layer thickness. The thermal conductivity values of the samples varied according to the additives and layer thicknesses. The highest thermal conductivity increase was measured in PLA-CF with 11.84%, and the lowest thermal conductivity decrease was measured in Tough PLA with 9.44%.

In the study conducted for the cooling systems of MALE class unmanned aerial vehicles using internal combustion engines, new type radiators were designed using spring-structure fins. Among the radiators formed with spring structures acting as fins, the radiator developed using springs with a pitch of 2.25 mm was named Radiator-Y1, the radiator developed using springs with a pitch of 4.25 mm was named Radiator-Y2, and the radiator developed using springs with a pitch of 8.25 mm was named Radiator-Y3. This design change is seen as an innovative method that can increase heat transfer on the radiator surface and increase cooling performance by increasing the turbulence effect of the air affecting the radiator. Experimental studies were carried out using single type (Al₂O₃ and ZnO) and hybrid (ZnO-CuO) nanofluids in addition to pure water. Experiments were carried out using different air speeds (8–10–12 m/s) and different coolant flow rates (20–22 L/min) and radiator performance was investigated. The effects of the surface area created by the spring structure and the turbulence effect on heat transfer were evaluated. As a result of the studies, Radiator-Y1 showed the best cooling performance among the radiators developed with spring structures, followed by Radiator-Y2 and Radiator-Y3. It was observed that the nanofluids used had a positive effect on the cooling performance compared with pure water, as did the hybrid nanofluid compared when compared with single type nanofluids.