CFD analysis for optimization of a thermal box for qualification testing of MRA

In the aeronautical sector, safety and reliability represent essential requirements. In this specific case, hydraulic actuators play a critical role in the flight control systems of helicopters. Their proper functioning is therefore crucial to ensure the stability, maneuverability, and safety of the aircraft. For this reason, actuators are subjected to rigorous environmental qualification tests, compliant with international regulations and standards such as RTCA DO-160, which certify their reliability across a wide range of operating conditions, including extreme thermal environments. This thesis work, carried out in collaboration with Microtecnica, aims at the thermo-fluid dynamic study of a climate-controlled box designed for the qualification testing of a Main Rotor Actuator (MRA). Inside the box, the actuator is exposed to controlled temperature conditions, reproduced using a ventilation system to heat or cool the air. One of the main requirements concerns the speed at which the desired steady-state temperature is reached: reduced stabilization times allow for increased test efficiency and lower overall costs of the qualification phase. To address this analysis, a numerical approach based on Computational Fluid Dynamics (CFD) was adopted. Simulations were conducted to investigate heat transfer phenomena and air circulation within the thermal box. The simulations enabled the evaluation of the spatial temperature distribution, thermal gradients, and characteristic times for reaching steady-state conditions under different configurations. Based on the results obtained, it was possible to identify configurations capable of significantly reducing stabilization times, thereby improving the overall efficiency of the testing process. The analyses also provided useful insights for optimizing the design of the thermal box and supporting company decisions in view of future experimental campaigns. In conclusion, the study demonstrates that the use of CFD simulations represents an effective tool for the analysis and optimization of testing systems in the aeronautical field. Beyond reducing test times and costs, this approach allows for a better understanding of the physical phenomena governing system dynamics, paving the way for further developments towards the creation of more accurate models for detailed analyses and experimental validation.