Browsing by Author "Smith, Lelanie"
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Item Open Access Computational investigation of the aerodynamic performance of an optimised alternative fuselage shape(Emerald, 2024-06-05) Odendaal, Diwan U.; Smith, Lelanie; Craig, Kenneth J.; Sanders, Drewan S.Purpose – The purpose of this study is to re-evaluation fuselage design when the main wing’s has the ability to fulfill stability requirements without the need for a tailplane. The aerodynamic requirements of the fuselage usually involve a trade-off between reducing drag and providing enough length for positioning the empennage to ensure stability. However, if the main wing can fulfill the stability requirements without the need for a tailplane, then the fuselage design requirements can be re-evaluated. The optimisation of the fuselage can then include reducing drag and also providing a component of lift amongst other potential new requirements. Design/methodology/approach – A careful investigation of parameterisation and trade-off optimisation methods to create such fuselage shapes was performed. The A320 Neo aircraft is optimised using a parameterised 3D fuselage model constructed with a modified PARSEC method and the SHERPA optimisation strategy, which was validated through three case studies. The geometry adjustments in relation to the specific flow phenomena are considered for the three optimal designs to investigate the influencing factors that should be considered for further optimisation. Findings – The top three aerodynamic designs show a distinctive characteristic in the low aspect ratio thick wing-like aftbody that has pressure drag penalties, and the aftbody camber increased surface area notably improved the fuselage’s lift characteristics. Originality/value – This work contributes to the development of a novel set of design requirements for a fuselage, free from the constraints imposed by stability requirements. By gaining insights into the flow phenomena that influence geometric designs when a lift requirement is introduced to the fuselage, we can understand how the fuselage configuration was optimised. This research lays the groundwork for identifying innovative design criteria that could extend into the integration of propulsion of the aftbody.Item Open Access Potential for energy recovery from boundary-layer ingesting actuator disk propulsion(AIAA, 2024-01-26) Mutangara, Ngonidzashe E.; Smith, Lelanie; Craig, Kenneth J.; Sanders, Drewan S.The theoretical benefits of highly integrated propulsion systems are highlighted herein by assessing the potential for energy recovery utilization using actuator disk propulsion. Decomposing aerodynamic forces into thrust and drag for closely integrated bodies, particularly those employing boundary-layer ingestion, becomes challenging. In this work, a mechanical energy-based approach was taken using the power balance method. This allowed the performance to be analyzed through the mechanical flow power in the fluid domain, disregarding the need for any explicit definition of thrust and drag. Through this, the benefit of boundary-layer ingestion was observed from a wake energy perspective as a decrease in the downstream mechanical energy deposition and associated viscous dissipation. From a propulsion perspective, the reduction in power demand necessary to produce propulsive force indicated the possibility of power savings by utilizing the energy contained within the ingested boundary-layer flow.Item Open Access Potential for energy recovery of unpowered configurations using power balance method computations(AIAA, 2021-07-30) Mutangara, Ngonidzashe E.; Smith, Lelanie; Craig, Kenneth J.; Sanders, Drewan S.New aircraft developments are made to improve aircraft performance and efficiency. One such method is integrating propulsion into the airframe. This allows for boundary-layer ingestion, which shows promise of significant power benefits. However, these benefits are difficult to quantify as the propulsion system and aircraft body become meticulously integrated. The thrust and drag are coupled and cannot be defined separately, making conventional performance analysis methods inapplicable. The power balance method (PBM) addresses this by quantifying aircraft performance in terms of mechanical flow power and change in kinetic-energy rate. The primary focus of this work was to perform computational studies implementing the PBM on unpowered aerodynamic bodies to evaluate their respective drag contributions. A secondary study was also conducted to quantify the energy recovery potential of various bodies using a potential for energy recovery factor. The computational fluid dynamics case studies showed that drag obtained using the PBM agreed to within 2% of conventional momentum-based approaches. Maximal energy recovery potential was consistently observed at the trailing ends of the geometries, with values ranging between 9 and 12%.Item Open Access Validation case studies of a numerical approach towards optimization of novel fuselage geometries(AIAA, 2023-01-19) Odendaal, Diwan U.; Smith, Lelanie; Craig, Ken; Mutangara, Ngonidzashe; Sanders, Drewan S.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.