Propulsion system integration on truss-braced aircraft: structural performance sensitivity to architectural design parameters

• Future sustainable aviation Goals: truss-braced wing (TBW) configurations, compatible with traditional or novel propulsion technologies, have been proposed to support sustainable aviation, necessitating an understanding of propulsion system design impacts. • Integrated propulsion system Sensitivities: coupled aerodynamic, flight dynamics, and structural dynamics models reveal that TBW configurations are more sensitive to powerplant location compared to conventional aircraft, highlighting the importance of such architectural design considerations. • Dynamic load Response: TBW configurations exhibit increased coupling between powerplant swing and wing bending modes, significantly influencing their dynamic response under gust loading scenarios. • Distinct sensitivities for propulsion Types: conventional TBW systems are more sensitive to powerplant mass, whereas hybrid-electric TBW systems are more influenced by pylon stiffness variations, underscoring the need for tailored structural optimisation. Strut-, or Truss-Braced Wing configurations, compatible with traditional or more novel propulsion technology, have been proposed to meet future sustainable aviation goals. However, an understanding of how propulsion system performance and/or design is impacted by such novel architectural changes is required to develop an optimal integrated propulsion system solution. With a focus on the structural characteristics of the propulsion system, this paper details how major architectural parameters (mass, stiffness and location of powerplant and airframe integration) impact the key structural response of the propulsion system. Coupled aerodynamic (DLM) – Flight Dynamics (FD) – Structural Dynamics (SD) whole aircraft models have been created for conventionally powered (TBW) and hybrid electric (TBWe) Truss-Braced Wing configurations. Models facilitate evaluation of key structural responses, of both airframe and powerplant, under a range of static and dynamic load cases. Sensitivity analysis concluded that Truss-braced Wing configurations were more sensitive to variation in powerplant spanwise location than a conventional Tube-and-Wing aircraft. Increased coupling between powerplant swing and wing bending modes is evident, influencing dynamic response under gust loading. Moreover, differences in the mass and stiffness characteristics of the conventional and electric propulsion system features has also yielded contrasting dominant parameter sensitivities – TBW is more sensitive to variation in powerplant mass, while TBWe is more sensitive to variation in pylon stiffness.