Adjoint Based Aerodynamic Shape Optimization of Subsonic Submerged Intake

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2021-5-04
AHMED, ALI
In this study the aerodynamic shape optimization of subsonic submerged intake is performed. The total pressure at the aerodynamic interface plane and lift are employed as objective functions. Drag is constrained and employed as penalty objective. Open-ware platforms are used including SALOME for solid modeling, GMSH for the hybrid mesh generation and SU2 for flow solutions and adjoint based shape optimization. Free form deformation box is employed for shape parameterization and surface deformation. Initially NACA intake placed on a flat plate is solved and result is compared with reference study at subsonic flow conditions. Thereafter single objective shape optimization is employed which enhances the CL/CD from 0.08 to 0.53 at the end of design cycles. The second case is of trapezoidal-entrance intake placed in slender aerodynamic body. The results are compared with reference study and baseline case for optimization is established. The shape is optimized using multi objective function and for multiple free form deformation boxes. The intake remains flush with the body during the shape deformation process. The intake internal surface is then allowed to deform along the optimization steps. The pressure recovery increases by 3%. The third case is similar but with circular entrance in slender body. A single free form deformation box encloses the intake region and the deformation is allowed such that optimization creates a semi-submerged shape. The total pressure recovery increases by 2% and CL/CD also increases by 10%. In the last case again the trapezoidal entrance intake is employed. The optimization process is similar to the third case. The optimum shape produces a substantial deformation at the intake surface and a semi-submerged intake is finally formed. The total pressure recovery improves by 6% and an additional CL/CD ratio of 0.04 is achieved.
Citation Formats
A. AHMED, “Adjoint Based Aerodynamic Shape Optimization of Subsonic Submerged Intake,” Ph.D. - Doctoral Program, Middle East Technical University, 2021.