Performance and Regulatory Assessment Trim Formulations for Conceptual Aircraft Design

This paper introduces a geometry-centric, open-source aircraft flight simulation framework designed to address limitations in traditional conceptual aircraft design methods, especially regarding regulatory-driven steady-state (trim) analyses. Conventional approaches, which primarily rely on empirical relationships developed from historical data, prove insufficient for accurately capturing emerging electrified propulsion systems and unconventional aircraft architectures. To overcome these challenges, the proposed framework integrates multidisciplinary analyses, accommodates models across a spectrum of fidelity—from low-fidelity empirical equations to detailed computational fluid dynamics (CFD) and experimental data—and supports various aircraft configurations, including fixed-wing and vertical-lift vehicles, conventional fuels and electric energy sources, and novel propulsion and powertrain architectures. Additionally, the framework leverages gradient-based optimization techniques, enabling efficient exploration of large-scale aircraft design spaces. Complementing this framework, the paper introduces specialized trim formulations structured as optimization problems. These formulations efficiently compute steady-state flight conditions and explicitly relate key aircraft performance metrics to applicable regulatory requirements outlined in 14-CFR, thus supporting certification-driven design. Demonstrations featuring a general aviation aircraft (Cessna 172), a commercial transport aircraft (Boeing 777), and NASA’s distributed electric propulsion concept (X-57) validate the framework's versatility and effectiveness across diverse aircraft configurations and use cases.