Comparison of adjoint‐based and feature‐based grid adaptation for functional outputs |
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| Authors: | R Balasubramanian J C Newman III |
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| Institution: | 1. Computational Simulation and Design Center, ERC, Mississippi State University, Box 9627, Mississippi State, MS 39762, U.S.A.;2. Department of Aerospace Engineering, Mississippi State University, Mississippi State, MS 39762, U.S.A. |
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| Abstract: | Adjoint‐based and feature‐based grid adaptive strategies are compared for their robustness and effectiveness in improving the accuracy of functional outputs such as lift and drag coefficients. The output‐based adjoint approach strives to improve the adjoint error estimates that relate the local residual errors to the global error in an output function via adjoint variables as weight functions. A conservative adaptive indicator that takes into account the residual errors in both the primal (flow) and dual (adjoint) solutions is implemented for the adjoint approach. The physics‐based feature approach strives to identify and resolve significant features of the flow to improve functional accuracy. Adaptive indicators that represent expansions and compressions in the flow direction and gradients normal to the flow direction are implemented for the feature approach. The adaptive approaches are compared for functional outputs of three‐dimensional arbitrary Mach number flow simulations on mixed‐element unstructured meshes. Grid adaptation is performed with h‐refinement and results are presented for inviscid, laminar and turbulent flows. Copyright © 2006 John Wiley & Sons, Ltd. |
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| Keywords: | adjoint error estimation grid adaptation functional outputs unstructured meshes |
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