Riassunto analitico
Aerodynamics has always been fundamental for vehicles, from boats to airplanes to road vehicles. Its importance on cars is increasing due to environmental regulations for traditional autos and travel ranges for electric vehicles. Aerodynamics modeling is not only a matter of significant changes in surfaces and components, but it is also a case of millimeter changes in corners and curvatures. As a result, when styling freezes and saturation of the aerodynamic development of the vehicle is reached, an optimization tool able to improve the aerodynamic targets without modifying vehicle style and in line with whatever constraint is chosen is of essential utility. A new automated industrial workflow for a final stage of aerodynamics optimization of high-performance vehicles based on adjoint methods, is proposed. The approach combines a CFD solver for RANS and DES simulations, a coupled adjoint solver, a surface morpher, and a vehicle CAD model; scripts are developed to automate and generalize the process. The model is first simulated using RANS or DES equations; the solution is then input into the adjoint solver to compute surface sensitivities concerning a cost function; such sensitivities are converted into a displacement, and input into the surface morpher. The process is then iterated up to target achievement. The proposed method is shown to be efficient and effective in optimizing aerodynamic performances maintain an invariant vehicle style. Optimizing a sport utility vehicle (SUV) demonstrates the proposed process’s effectiveness and limits. Furthermore, a benchmark activity ensures workflow flexibility on cars of different segments and cost functions.
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