Advances in scientific computing have made modelling and simulation an important part of the decision-making process in engineering, science, and public policy. This book provides a comprehensive and systematic development of the basic concepts, principles, and procedures for verification and validation of models and simulations. The emphasis is placed on models that are described by partial differential and integral equations and the simulations that result from their numerical solution. The methods described can be applied to a wide range of technical fields, from the physical sciences, engineering and technology and industry, through to environmental regulations and safety, product and plant safety, financial investing, and governmental regulations. This book will be genuinely welcomed by researchers, practitioners, and decision makers in a broad range of fields, who seek to improve the credibility and reliability of simulation results. It will also be appropriate either for university courses or for independent study.

/pdf/verification-and-validation-in-scientific-computing-262w5ti0ia.pdf

Verification and Validation in Scientific Computing

This report documents the results of a study to address the long range, strategic planning required by NASA's Revolutionary Computational Aerosciences (RCA) program in the area of computational fluid dynamics (CFD), including future software and hardware requirements for High Performance Computing (HPC). Specifically, the "Vision 2030" CFD study is to provide a knowledge-based forecast of the future computational capabilities required for turbulent, transitional, and reacting flow simulations across a broad Mach number regime, and to lay the foundation for the development of a future framework and/or environment where physics-based, accurate predictions of complex turbulent flows, including flow separation, can be accomplished routinely and efficiently in cooperation with other physics-based simulations to enable multi-physics analysis and design. Specific technical requirements from the aerospace industrial and scientific communities were obtained to determine critical capability gaps, anticipated technical challenges, and impediments to achieving the target CFD capability in 2030. A preliminary development plan and roadmap were created to help focus investments in technology development to help achieve the CFD vision in 2030.

/pdf/cfd-vision-2030-study-a-path-to-revolutionary-computational-3hk79p0tz6.pdf

CFD Vision 2030 Study: A Path to Revolutionary Computational Aerosciences

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

/pdf/review-of-output-based-error-estimation-and-mesh-adaptation-gx0exr3453.pdf

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

http://www-personal.umich.edu/~kfid/pubs/Fidkowski_Oliver_Lu_Darmofal_2005.pdf

p-Multigrid solution of high-order discontinuous Galerkin discretizations of the compressible Navier-Stokes equations

https://cfwebprod.sandia.gov/cfdocs/CompResearch/docs/Oberkampf-Trucano-SAND2007-0853.pdf

Verification and validation benchmarks

Results from the Second AIAA Drag PredictionWorkshop are summarized. The workshop focused on absolute
and configuration delta drag prediction of the DLR, German Aerospace Research Center F6 geometry, which is
representative of transport aircraft designed for transonic flight. Both wing–body and wing–body–nacelle–pylon
configurations are considered. Comparisons are made using industry relevant test cases that include single-point
conditions, drag polars, and drag-rise curves. Drag, lift, and pitching moment predictions from several different
Reynolds averagedNavier–Stokes computational fluid dynamics codes are presented and compared to experimental
data. Solutions on multiblock structured, unstructured, and overset structured grids using a variety of turbulence
models are considered. Results of a grid-refinement study and a comparison of tripped transition vs fully turbulent
boundary-layer computations are reported.

Data Summary from Second AIAA Computational Fluid Dynamics Drag Prediction Workshop

The results from the first AIAA Computational Fluid Dynamics (CFD) Drag Prediction Workshop are summarized. The workshop was designed specifically to assess the state of the art of CFD methods for force and moment prediction. An impartial forum was provided to evaluate the effectiveness of existing computer codes and modeling techniques and to identify areas needing additional research and development. The subject of the study was the German Aerospace Research Center DLR-F4 wing-body configuration, which is representative of transport aircraft designed for transonic flight. Specific test cases were required so that valid comparisons could be made. Optional test cases included constant C L drag-rise predictions typically used in airplane design by industry. Results are compared to experimental data from three wind-tunnel tests. A total of 18 international participants using 14 different codes submitted data to the workshop

Thomas Zickuhr

Papers

Data Summary from Second AIAA Computational Fluid Dynamics Drag Prediction Workshop

Data summary from the first AIAA Computational Fluid Dynamics Drag Prediction Workshop