An investigation of the thermal conductivity of a satellite panel with lattice core fabricated by additive manufacturing

In recent years, additive manufacturing (AM) technology has widely been preferred in the design of structural subsystems within the space industry. Traditional manufacturing methods present various challenges, particularly in the production of honeycomb sandwich panels, including high labor costs, complex quality control processes, and stringent tolerance requirements. To overcome these limitations, AM enables the fabrication of lightweight and high-strength structures with complex geometries by sequentially joining material layer by layer. The design flexibility offered by AM in space structures facilitates the development of optimized lattice structures, leading to significant improvements in both mechanical strength and thermal performance. The literature includes successful applications of AM-fabricated thermal control components, such as heat exchangers, heat sinks, and heat pipes. This trend supports the increasing adoption of AM in the space sector and highlights its potential as a significant innovation in satellite structural subsystems. This thesis aims to investigate the thermal conductivity of lattice-core sandwich panels designed for satellite structural subsystem through analytical, numerical, and experimental methods. In this study, the thermal conductivity performance of lattice-core sandwichpanels with different strut diameters has been evaluated. A literature review was conducted, and based on the findings from studies on lattice structures, analyses were carried out using analytical, numerical, and experimental approaches. When comparing the results obtained from the analytical and numerical methods, differences ranging from 0.8% to 6.3% were observed as a function of the strut diameter. These differences stay within the error margins typically accepted in the literature. Additionally, the analyses revealed a directly proportional relationship between the strut diameter of the lattice structure and its thermal conductivity. Due to the high production and testing costs, only one of the designed panels was produced using the Selective Laser Melting (SLM), one of the metal AM technologies. Since this panel was designed for satellite structural subsystem, it was tested in a vacuum environment to simulate the space conditions. Experimental results showed a maximum difference of 9% from theoretical calculations. This difference is believed to be due to factors such as uncertainties in the test environment and geometric variations during the manufacturing process. Furthermore, to simulate the thermal behavior of the panel observed in the experiment, a finite element model of the experimental setup was created. The numerical analysis performed on this model resulted in temperature differences between the numerical predictions and experimental measurements, which generally stayed within a thermal uncertainty margin of ±1.5 °C.