Validation of an Approach towards Fuselage Optimization for Effective Boundary Layer Ingestion

Abstract

Optimization studies for improved fuselage designs primarily focus on drag reduction. However, when considering an alternative configuration where the stability requirements are assumed to be fulfilled by the main wing, eliminating the need for a tailplane, the fuselage design requirements are reconsidered. This work considers not only the reduction of drag but ensuring a component of lift as well as considering energy recovery potential for propulsion integration. The numerical modelling approach (turbulence model selection, optimization strategy and application of the Power Balance Method) is evaluated through a series of validation cases to determine a level of robustness and certainty. Three cases studies are completed: a 2D, compressible transonic RAE2282 airfoil, a 3D, incompressible low-drag body F-57 and a 3D, compressible body MBB3. The final approach includes a polyhedral mesh and SST k-ω turbulence model combined with multi-objective tradeoff optimization. Application of the Power Balance Method was validated within 1% for incompressible cases, however for the compressible cases the drag coefficient showed increasing deviation (1.3%) due to residual dissipative quantities.

Computational investigation of the aerodynamic performance of an optimised alternative fuselage shape

“…The mesh construction was similar to the 3D axisymmetric transonic validation study (Odendaal et al , 2023). The domain size for the study indicated a distance of 6 body lengths behind the body was sufficient to capture the drag coefficient with less than one 1% difference.…”

“…The multi-objective trade-off optimisation algorithm SHERPA was used based on its capability to make large geometrical changes, which constantly refines each parameter input range to provide multiple optimum geometries. All the models selected were based on the comparative studies and validation completed in Odendaal et al (2023). The simulations were completed on a single personal computer with 16-cores and took approximately 65 days to complete the optimisations.…”

“…The volumetric mesh refinement zones follow similar approaches to the 3D axisymmetric transonic validation study completed by Odendaal et al (2023). The first refinement zone is around the fuselage.…”

“…This work explores an approach that combines a RANS model with a multi-objective trade-off optimisation model in Star-CCM1, which was validated in Odendaal et al (2023), to optimise fuselages to include lift. Including the geometric suggestions from Huyssen et al (2012) and Smith et al (2017Smith et al ( , 2019 towards finding different ideal fuselage shapes.…”