Effect of Emissivity on Wall Temperature of Air Frames

Abstract This study explores the influence of emissivity on the surface temperature of airframes under transient thermal conditions, employing ANSYS APDL for simulation. The research is driven by the critical need for effective thermal management in airframes, which are essential structural components in aerospace and automotive industries. The analysis was conducted on a hollow steel airframe with an external diameter of 250 mm, an internal diameter of 248 mm, and a length of 300 mm. The model was discretized using solid-8 node 70 element, with a mesh size of 1 mm. A constant heat flux of 10,000 W/m² was applied to the airframe’s wall over a period of 300 seconds, with a time step of 1 second, to simulate the heat transfer conditions. The study systematically varied the emissivity from 0.05 to 1, in increments of 0.05, to assess its impact on the airframe's surface temperature. Results indicate a clear inverse relationship between emissivity and surface temperature. As emissivity increases, the airframe's ability to emit thermal radiation improves, leading to a significant reduction in surface temperature. This effect is particularly pronounced at higher emissivity values, where a substantial decrease in surface temperature was observed. The findings underscore the pivotal role of emissivity in thermal management. Airframes with higher emissivity demonstrate enhanced heat dissipation capabilities, which is critical for maintaining structural integrity under high thermal loads. The study provides valuable insights for the design and optimization of airframes, particularly in applications where precise thermal regulation is essential. By selecting materials with appropriate emissivity characteristics, engineers can achieve superior thermal performance, thereby improving the safety, durability, and efficiency of airframes in demanding operational environments.