Thermal–Structural Assessment of a Convergent Nozzle for UAV Applications Using Advanced Steady‐State Thermal Analysis

This study presents an in‐depth structural evaluation of the convergent nozzle in a microgas turbine engine (MGTE), focusing on the performance of various lightweight materials used in aerospace applications. The research investigates both structural and aerothermal characteristics of the nozzle under realistic operating conditions. A total of 17 lightweight materials, including advanced carbon fiber–reinforced polymers (CFRPs), glass fiber–reinforced polymers (GFRPs), and conventional aerospace alloys, are assessed using advanced fluid–structure interaction (FSI) techniques. All simulations are conducted under uniform inlet conditions with a baseline temperature of 302.5 K. Utilizing a robust coupling between fluid, thermal, and structural domains, the analysis ensures accurate thermal load transfer and stress prediction. The structural integrity, heat tolerance, and deformation characteristics of each material are examined in detail. The validation process yielded an error margin of just 5.36% between analytical and computational results, confirming the reliability of the simulation framework. Among the evaluated materials, E‐GFRP‐UD demonstrated outstanding performance by exhibiting a 65.49% reduction in thermal stress and minimal deformation of only 0.0248 mm compared to the baseline structural steel. These findings highlight E‐GFRP‐UD as a highly promising candidate for MGTE nozzle applications, offering superior thermal resistance, structural stability, and extended operational life under complex loading conditions.