ADJOINT BASED SHAPE OPTIMIZATION OF SEMI-SUBMERGED INLETS AND DEVELOPMENT OF A NOVEL BOUNDARY LAYER DIVERTER

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2022-12-28
Küçük, Umut Can
In this study, boundary layer ingesting and diverting submerged air inlets are design optimized with an adjoint-based optimization methodology based on RANS solu tions. The opensource SU2 software is employed for both RANS and adjoint solutions and for driving the gradient-based optimization. Total pressure recovery at the aerodynamic interface plane is taken as the main objective of the optimization, and the mass flow rate and the momentum distortion are closely monitored. It is first shown that the shape optimization of an inlet duct for a semi-submerged boundary layer ingesting inlet provides a limited performance increase since the performance of the inlet strongly depends on the amount of ingested boundary layer which develops over the upstream wall. The shape optimization of the upstream wall together with the inlet duct is next performed and is shown that the performance of the inlet is improved significantly. The optimum upstream wall obtained now provides a bound ary layer diverting inlet. Based on the optimum upstream wall configuration, a novel boundary layer diverter is then designed and similarly adjoint optimized. The design optimized novel boundary layer diverter is highly compact, flush to the surface and has a lower drag compared to the conventional diverter geometries. It provides a 2.4% increase in total pressure recovery and a 64% decrease in circumferential momentum distortion. It is also shown that further performance increase is achievable when the duct and the flush diverter are optimized together.

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Citation Formats
U. C. Küçük, “ADJOINT BASED SHAPE OPTIMIZATION OF SEMI-SUBMERGED INLETS AND DEVELOPMENT OF A NOVEL BOUNDARY LAYER DIVERTER,” Ph.D. - Doctoral Program, Middle East Technical University, 2022.