A Conceptual Model-based Design Approach for the Development of a New Hydraulic System Architecture for the UAV Class of Aircraft Application

Advancements in aerospace system design are essential for improving efficiency, reducing weight, minimizing failures, and enhancing reliability while maintaining cost-effectiveness. This study presents a novel hydraulic system architecture for UAV-class aircraft, derived from conventional aircraft hydraulic designs. A conceptual modeling approach was employed to develop the system schematic, which was analyzed using LMS Amesim software to assess its performance under various conditions. The proposed system integrates a variable delivery piston hydraulic pump, an emergency accumulator, a bootstrap reservoir, and various hydraulic control valves. The design ensures optimal functionality while incorporating redundancy through an emergency landing gear extension mechanism. Hydraulic actuators control landing gear operations, with solenoid-operated selector valves regulating fluid flow based on operational needs. A shuttle valve allows automatic switching between the main hydraulic system and the emergency accumulator during system failures, ensuring reliability. LMS Amesim simulations validated key performance aspects, including pump pressure stabilization, accumulator charging behavior, landing gear actuation, and shuttle valve functionality. Results indicated stable pump operation at 206 bar, with emergency accumulator charging reaching 200 bar. The undercarriage system demonstrated smooth extension and retraction, with jack piston pressure transitions from 30 to 209 bar. The shuttle valve effectively switched between main and emergency hydraulic sources, enhancing system redundancy. Future improvements will focus on optimizing pump surge behavior, refining accumulator charging characteristics, integrating braking applications, and expanding hydraulic functionalities such as flap circuits. These enhancements will improve system robustness, efficiency, and fail-safe operation. This study demonstrates that conceptual modeling, combined with LMS Amesim simulations, is an effective approach for developing reliable hydraulic architectures for UAV-class aircraft, providing a strong foundation for future aerospace hydraulic advancements.