SANS Contributions to Case CR1

Marshall C. Galbraith

Aerospace Computational Design LaboratoryDepartment of Aeronautics and Astronautics

Massachusetts Institute of Technology

Galbraith (MIT) SANS Contributions to Case CR1 6 January 2018 1 / 12

SANS

Solution Adaptive Numerical Simulator (SANS):PDE agnostic (advection-diffusion-reaction)

RANS: negative-SAAutomatic Differentiation

Stabilized-CG, DG, HDG, EDG discretizationsDG-BR2 used here

Linear SolversGMRESUMFPACK, MKL-PARDISO, and PETSc interfaces(PETSc GMRES with ILU used here)

Non-linear SolverNewton-Raphson with line searchPTC and P-Sequencing used here

Output-based mesh adaption using MOESSminimize estimated error in output functionalsubject to DOF count ≤ set cost

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Joukowski Airfoil Verification

SUPG O(h2P), asymptotically dual consistent?

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CRM High-order Workshop Meshes: CD

Mach=0.3. Decreased variation with increased P and Q.Galbraith (MIT) SANS Contributions to Case CR1 6 January 2018 4 / 12

CRM High-order Workshop Meshes: CL

Mach=0.3. Relatively small variation.Galbraith (MIT) SANS Contributions to Case CR1 6 January 2018 5 / 12

Mesh Adaptation

Initial Mesh

Boeing metric based mesh generator EPICCurving not robust enough for adaptationPoor DG P1 Q1 discretization for adaptation

Target: 2.0M DOF (625 k elements) with drag adjoint

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Mesh Adaptation

Initial Mesh

Boeing metric based mesh generator EPICCurving not robust enough for adaptationPoor DG P1 Q1 discretization for adaptation

Target: 2.0M DOF (625 k elements) with drag adjointNot enough DOF for poor P1 Q1 DG discretizationI’m gonna need a bigger box

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Adapted Mesh: Isometric View

Initial0.65M DOFs

Adapted2.3M DOFs

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Adapted Mesh: Side View

Initial0.65M DOFs

Adapted2.3M DOFs

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Adapted Mesh: Side View Crinkle Cut

Initial0.65M DOFs

Adapted2.3M DOFs

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Adapted Mesh: Fairing Side View

Initial, 0.65M DOFs Adapted, 2.3M DOFs

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Adapted Mesh: Wing Root

Initial, 0.65M DOFs Adapted, 2.3M DOFs

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Summary

Small variation in CDFor P2 less than 1 count across all meshesHow coarse can we go?

Relatively small variation in lift

Mesh AdaptationNeed robust metric conforming mesh curvingPoor P1 Q1 needs more DOF.Lack of resolution in boundary layers.

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