Error estimation and control are critical ingredients for improving the reliability of computational simulations Adjoint-based techniques can be used to both estimate the error in chosen solution outputs and to provide local indicators for adaptive refinement This article reviews recent work on these techniques for computational fluid dynamics applications in aerospace engineering The definition of the adjoint as the sensitivity of an output to residual source perturbations is used to derive both the adjoint equation, in fully discrete and variational formulations, and the adjoint-weighted residual method for error estimation Assumptions and approximations made in the calculations are discussed Presentation of the discrete and variational formulations enables a side-by-side comparison of recent work in output-error estimation using the finite volume method and the finite element method Techniques for adapting meshes using output-error indicators are also reviewed Recent adaptive results from a variety of laminar and Reynolds-averaged Navier-Stokes applications show the power of output-based adaptive methods for improving the robustness of computational fluid dynamics computations However, challenges and areas of additional future research remain, including computable error bounds and robust mesh adaptation mechanics

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Review of Output-Based Error Estimation and Mesh Adaptation in Computational Fluid Dynamics

Fully anisotropic goal-oriented mesh adaptation for 3D steady Euler equations

High-order sonic boom modeling based on adaptive methods

Computational framework for Launch, Ascent, and Vehicle Aerodynamics (LAVA)

uid dynamics solutions are gathered from nineteen participants representing three countries for the two required cases, an axisymmetric body and simple delta wing body. Structured multiblock, unstructured mixed-element, unstructured tetrahedral, overset, and Cartesian cut-cell methods are used by the participants. Participants provided signatures computed on participant generated and solution adapted grids. Signatures are also provided for a series of uniformly rened workshop provided grids. These submissions are propagated to the ground and noise measures are computed. This allows the grid convergence of a noise measure and a validation metric (dierence norm between computed and wind tunnel measured near-eld signatures) to be studied for the rst time. A statistical analysis is also presented for these measures. An optional conguration includes fuselage, wing, tail, ow-through nacelles, and blade sting. This full conguration exhibits more variation in eleven submissions than the sixty submissions provided for each required case. Recommendations are provided for potential improvements to the analysis methods and a possible subsequent workshop.

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Summary and Statistical Analysis of the First AIAA Sonic Boom Prediction Workshop

A wind-tunnel investigation was conducted to determine the effect of wing planform on sonic boom at Mach numbers of 1.7, 2.0, and 2.7. The results of the investigation show that the wing leading-edge sweep is one of the primary planform variables affecting the overpressure characteristics.

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Some Effects of Wing Planform on Sonic Boom

Mach number and geometry effects on level of sonic boom overpressure and applicability of Whitham theory to calculation of sonic boom

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J. P. Mendoza

Papers

Some Effects of Wing Planform on Sonic Boom

Some effects of Mach number and geometry on sonic boom