Conceptual Design and Initial Sizing Framework for Supersonic Unmanned Combat Aerial Vehicles

This paper presents a transparent, modular, and physics-based framework for the conceptual design and initial sizing of supersonic Unmanned Combat Aerial Vehicles (UCAVs), tailored to a defined time-critical strike mission. The target mission involves a supersonic ingress and egress totaling 1000 km, with payload delivery of 1000 kg, all within an endurance cap of 1 hour and operational constraints on takeoff, landing, and stability. Developed in a Python-based environment, the framework integrates classical aerodynamic modeling, Breguet-based fuel estimation, and constraint filtering to evaluate hundreds of configurations across a three-variable design space: cruise Mach number, wing aspect ratio, and sweep angle. Instead of relying on black-box solvers, a parametric sweep approach is used to preserve traceability and highlight design trade-offs. A mission-specific performance metric, the Vehicle Performance Score (VPS), is introduced to rank configurations based on aerodynamic efficiency, payload fraction, and constraint compliance. The optimal design had a wing aspect ratio and sweep of 3.0 and 45°, respectively, and cruises at a Mach number of 2.42, with a payload of 1000 kg and takeoff gross weight (TOGW) of 9900 kg. The framework was also extended to explore alternative objectives (minimum TOGW, minimum fuel weight) and to test adaptations of legacy (MiG-21) and stealth (nEUROn, Taranis) airframes. Results confirm the viability of the framework for mission-driven sizing of supersonic UCAVs, enabling rapid design iteration with built-in extensibility for high-fidelity aerodynamics, control integration, and stealth modeling in future studies.