Adjoint-based aerodynamic shape optimization including transition to turbulence effects

Halila, Gustavo Luiz Olichevis; Martins, Joaquim R. R. A.; Fidkowski, Krzysztof J.

doi:10.1016/j.ast.2020.106243

Cited by 33 publications

(1 citation statement)

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“…Such advanced techniques, therefore, minimize the computational cost of the optimization process. Gradient-based methods have been developed mainly for aerospace applications to enhance lift and reduce drag for airfoils geometries 36 , 37 but also have great potential for heat exchangers technology. The present work chooses the Adjoint method for several reasons.…”

Section: Introductionmentioning

confidence: 99%

Advancing thermal performance through vortex generators morphing

Ali

Dbouk

Wang

et al. 2023

Sci Rep

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The design of rigid vortex generators (RVG) influences the thermal performance of various technologies. We employed Discrete Adjoint-Based Optimization to show the optimal development of vortex generators. Under turbulent flow conditions, different bi-objective functions on the RVG design were examined. Specifically, we aimed at an optimal RVG shape that minimizes the pressure drop and maximizes the local heat transfer in a rectangular channel. We show that an optimal design of an RVG can be obtained using computational fluid dynamics in conjunction with the Pareto Front at a computational cost of the order ~$$O(10^{-1})$$ O ( 10 - 1 ) . We obtained three essential vortex generator shapes based on the RVG morphing technique. Compared to the baseline geometry of a delta winglet pair DWP, the first morphed design reduced the pressure drop by $$39\%$$ 39 % , however, at the expense of a $$21\%$$ 21 % reduction in the Nusselt number. The second vortex generator design enhanced the heat transfer by $$18\%$$ 18 % , however, at the cost of a significant increase in pressure drop of about $$40\%$$ 40 % . The final morphed design achieved the highest thermal performance factor of 1.28, representing a heat transfer enhancement of $$6\%$$ 6 % with a moderate increase in pressure drop of about $$13\%$$ 13 % compared to DWP vortex generators. Furthermore, we investigated the effect of introducing different size holes on the mass reduction of vortex generators and their thermal performances. The mass of vortex generators can be reduced by $$9\%$$ 9 % and with an increase of $$7\%$$ 7 % in thermal performance factor concerning the DWP baseline. The findings of this study will lead to highly efficient lightweight heat exchangers.

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Section: Introductionmentioning

confidence: 99%

Advancing thermal performance through vortex generators morphing

Ali

Dbouk

Wang

et al. 2023

Sci Rep

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The continuous adjoint method to the γ−R˜eθt$$ \gamma -\tilde{R}{e}_{\theta t} $$ transition model coupled with the Spalart–Allmaras model for compressible flows

Kontou,

Trompoukis,

Asouti

et al. 2024

Numerical Methods in Fluids

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The continuous adjoint method for transitional flows of compressible fluids is developed and assessed, for the first time in the literature. The gradient of aerodynamic objective functions (aerodynamic forces) with respect to design variables, in problems governed by the compressible Navier–Stokes equations coupled with the Spalart–Allmaras turbulence model and the transition model (in three, non‐smooth and smooth, variants of it), is computed based on the continuous adjoint method. The development of the adjoint to the smooth transition model variant proved to be beneficial. The accuracy of the computed sensitivity derivatives is verified against finite differences. Programming is performed in an in‐house, vertex‐centered finite‐volume code, efficiently running on GPUs. The proposed continuous adjoint method is used in 2D and 3D aerodynamic shape optimization problems, namely the constrained optimization of the NLF(1)–0416 isolated airfoil and that of the ONERA M6 wing. The impact of “frozen transition” (assumption according to which the adjoint to the transition model equations are not solved) or “frozen turbulence” (by additionally ignoring the adjoint to the turbulence model) are evaluated; it is shown that both lead to inaccurate sensitivities.

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