Intelligent Light and FieldView

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Put our experts to work for you. Aerospace America October 2017

​Intelligent Light welcomes two new CFD experts to our team:

  • Dr. Steve Makinen, Custom Engineered Solutions (CES) team, brings a wealth of knowledge and experience shaping Flight Sciences technology.
  • Seth Lawrence, Applied Research Group (ARG), adds a specialist with expertise in Uncertainty Quantification (UQ) for CFD.

Aerospace America Advertisement – October 2017 (click to enlarge)

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Uncertainty Quantification (UQ) at ASME V&V Symposium

Uncertainty Quantification (UQ) of CFD data.

Earlier this month at the ASME V&V symposium, Seth Lawrence, a graduate student at our University Partner Northern Arizona University, presented his Master's thesis work on "Verification, Validation and Uncertainty Quantification of Turbulent Twin Jets". Seth was advised by our own Dr. Duque who maintains an adjunct Faculty position @ NAU. This event was Seth's first outing at a major international technical symposium. He did a great job of presenting (and defending) his work to the leaders in the field of V&V/UQ, such as Oberkampf, Roy, Celik and Eca. The work was a Challenge Problem sponsored by the ASME V&V 30 Committee.  GREAT JOB SETH!    

In Uncertainty Quantification (UQ), engineers utilize standardized procedures such as the ASME V&V 20 and V&V 30 guidelines to account for the effects of probabilistic inputs to a CFD simulation to arrive at a non-deterministic answer. Through UQ, an engineer could state with 95% certainty answers to their design question while justifying and documenting how they arrived at their answer.

This challenge problem was the only one at the symposium to focus on UQ. It is a key area of interest for those seeking to capitalize on information gleaned from verification & validation work in new design studies. 

To combine CFD and UQ analysis, Mr. Lawrence created an automated workflow using FieldView to post-process the results of Fluent solutions and pass data to Dakota (Sandia National Lab) and then pass data from Dakota as input to Fluent in an iterative process. FieldView was also used to visualize the CFD data to create images for the presentation and 3D PDF to share results.

"Seth did a great job presenting to the leaders in the VVUQ community. His work was well received and cited by other presenters later in the symposium.  It was gratifying to hear statements among veteran symposium participants including 'This is the first time I've seen error bars on a CFD result, very impressive.'"

Earl P. N. Duque, PhD Manager of Applied Research at Intelligent Light

Mr. Lawrence noted that he enjoyed the chance to see how the experts in this field approached the benchmark ASME turbulent twin jet numeric model validation problem.

Professor Tom L. Acker from NAU and Intelligent LIght's Earl P.N. Duque served as advisers on the project.

​Mr Lawrence used the 3D PDF export capability in FieldView throughout the development of the CFD model, allowing him to easily share results of his grid convergence study (CGI) and in the observed order of the solver (p-obs). 3D PDF files are downloadable below.

"Throughout the development of the CFD model, I made good use of the 3D PDF generator that is available in the new FieldView 16.1 package. This was very helpful in the presentation of model results, and provided the ability to easily send detailed model results of large CFD datasets in the form of a small file via email, and the recipient does not need any special software to view the 3D PDF results - fantastic!"

Seth Lawrence, Northern Arizona University

Download 3D PDF. 

Numerical uncertainty in y-velocity.

Download 3D PDF.

Observed y-velocity.

Adobe Acrobat Reader recommended for viewing. Do not attempt to open these 3D PDF documents from your web browser. It will fail, showing a black window with a colorbar. Adobe Acrobat Reader is needed to properly display the 3D content contained in these documents.  Once loaded in Adobe Acrobat Reader, the following message may appear, depending on your security settings: "3D content has been disabled. Enable this feature if you trust this document". From the Options menu, select "Trust this document…" and click anywhere in the document to cause a refresh of the graphics.


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UQ with Dakota & FieldView XDB Workflow at Overset Grids Symposium October 17–20, 2016

As CFD users increasingly exploit ultrascale HPC capability and approach the realm of exascale, they will run studies consisting of many related simulations at very high fidelity. This will give engineers and researchers both the ability and need to assess the quality of their simulations. When simulation quality has been vetted, engineering judgments and investment decisions can be made with confidence. 

Uncertainty Quantification (UQ) provides a means to support this need and Intelligent Light has been working on integrating UQ tools including Sandia National Lab's Dakota in an extract-based (XDB) workflow where processing takes place while solutions are in memory and data storage/transfer needs are dramatically reduced.

Dr. Earl P. N. Duque will present "Uncertainty Quantification with Dakota-OVERFLOW within an in situ based FieldView XDB Workflow" at the Overset Grids Meeting. Meet with Dr. Duque and Joe Oliver, Global Sales Manager, to learn how FieldView users are getting more information from their data. Put the latest in high-productivity post-processing, in situ processing and CFD data management techniques to work for you.

Intelligent Light is proud to sponsor this year's symposium which will be held at the Future of Flight Aviation Center in Mukilteo, Washington on October 17-20, 2016.

Attending? Request a meeting.

Presentation Abstract:

Uncertainty Quantification with Dakota-OVERFLOW Within an In Situ Based FieldView XDB Workflow
Authors:
Earl P.N. Duque, Intelligent Light
Dan Heipler, Intelligent Light

NASA has called out the integration of VV/UQ tools into engineering workflows as a vital component of its "CFD Vision 2030 Study". In that document, the authors assert that as exascale computing becomes available, the capability to perform many highly resolved CFD simulations will become ubiquitous, enabling the ability, and need, to perform UQ and sensitivity analysis. To address this need, this presentation summarizes current work whereby the Dakota code drives an ensemble of OVERFLOW2 jobs to explore a nested epistemic-aleatory parameter space. Concurrently, OVERFLOW2 instrumented with VisIt/Libsim creates FieldView XDB surfaces via in situ processing to reduce the data for post-hoc visualization and analysis. The presentation presents UQ concepts in general and their implementation within the current framework.

This work is sponsored by a DOE Office of Science grant (DE-SC0015162)


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Next Generation Transport Aircraft Workshop 2016

NGTransportAircraftWorkshop16 次世代航空機ワークショップ

I was grateful to be invited to participate and represent Intelligent Light at the Next Generation Transport Aircraft Workshop held in February, 2016 in Hawaii. The conference brought together leaders from industry and universities in Japan and the United States who are working to develop transport aircraft of the future.

Major tracks of presentation and discussion were:

  • CFD methodologies and applications
  • High order numerical methods in CFD
  • Uncertainty Quantification (UQ) and optimization
  • Data assimilation
  • Carbon Fiber Reinforced Polymer (CFRP) Laminates
  • Failure modes for composite structures
  • 3D printing of continuous carbon fiber reinforced plastics

I found Dr. John C. Halpin’s (JCH Consultants, Inc.) keynote presentation “The Aging Composite Airframe” to be a fascinating discussion and a great start to the meetings. Dr. Halpin asks the question: How long should a composite airframe last? While non-composite aircraft have an estimated service life of 35-40 years, carbon fiber plastics service life is estimated at around 20 years. Experience shows delamination based on power load and Mode 1 simulations are commonly run while Modes 2 and 3 are infrequently run due to the computation cost of these simulations. Accurate simulations are needed to develop appropriate safety standards for these aircraft.

Intriguing too was the use of SPH for bird strike simulations described in Shigeki Yashiro’s (Shizuoka Univ. Japan) presentation "Numerical analysis of bird strike on CFRP laminates using smoothed particle hydrodynamics in a generalized coordinate system". SPH handles the deformation well but is not suitable for representing microscopic damage as the particles are uniformly distributed. Dr. Yashiro modified his code to handle arbitrarily defined spacing of particles to produce credible results for this microscopic damage.

It is clear that some very interesting work is being done in the universities to develop methods and tools to address the challenges of working with composite materials. Further, the range of configurations and operating conditions will require probabilistic evaluation and uncertainty quantification (UQ) to develop safety standards and design targets for heavy lift aircraft. While the researchers are developing methods, industry is developing repeatable and reliable production workflows with mature tools and technology. Industry leaders are eager to speed development and increase accuracy using new methods and workflows that are proven and reduce program risks.

I wish to express my gratitude to the organizers for their kind invitation. I was pleased to contribute to and learn from the discussions with my colleagues.

次世代航空機ワークショップ

2016年2月にハワイで開催された次世代航空機ワークショップにIntelligent Light(弊社)の代表として参加させて頂きました。このワークショップでは日米の次世代航空機の研究開発を行っている企業及び大学が集まり、研究発表や意見交換が行われました。

主なトピックは以下の通りです。

  • CFD手法及び適用
  • 高次精度CFD
  • 不確かさの定量的評価、最適化
  • データ同化
  • CFRP
  • 複合材料の破壊モード解析
  • 複合材料の3次元プリント

その中でもDr. John C. Halpinによるキーノート発表「The Aging Composite Airframe」はとても興味深い発表でした。発表の中で、Halpin博士は複合材料で航空機を設計する際に、そもそも複合材料で作る航空機フレームは何年持つべきなのかと問いかけていました。現在の金属製の航空機は約35年から40年の寿命を設定して作られている一方、現行の複合材料の寿命は約20年 と言われているそうです。現在複合材料の剥離解析は第1モードのみで行われており、計算コストの高い第2第3モードは考慮されていない事が多いそうです。 より正確な多モード解析を行うことによって、より正確な材料の劣化予測が出来るようになり、安全な材料の開発につながるそうです。

また静岡大学の矢代先生らによるSmoothed Particle Hydrodynamics(SPH)法を用いたバードストライクによる剥離解析研究も興味深いものでした。SPH法 はシミュレーションに格子を用いない粒子法のシミュレーション手法の一つです。格子を使用しないので、層剥離や変形を容易に取り扱う事が出来るという利点 がありますが、粒子を均等に配置する必要があるので粒子サイズ以下の小さいサイズのダメージを取り扱うのが難しいという問題があるそうです。そこで、粒子 間隔を任意に設定出来るようにする事により粒子サイズ以下のダメージを表せる新しいアルゴリズムを開発されたそうです。

本ワークショップにて次世代航空機の開発に 向けた様々な研究を学ぶことができました。上記の研究以外にも安全基準の策定のための不確定性の定量評価等も盛んに行われている様です。大学では革新的な 手法の開発、一方企業での研究では開発スピードの向上と同時にリスク低減に向けたより精度の高いワークフローの開発に重点が置かれ、より実用的な研究が行われていると感じました。

本ワークショップに参加させて頂いた事に感謝の意を示すと共に、このような会に参加させて頂いた事を光栄に思います。

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