Views from Intelligent Light
Roger Rintala

Duque Presentation: Large Scale Unsteady CFD via In-Situ CFD Data Management

Embry-Riddle

Accelerating the Post‐Processing of Large Scale Unsteady CFD Applications via In Situ Data Reduction and Extracts
Dr. Earl P.N. Duque
Manager of Applied Research, Intelligent Light

Tuesday, April 14th, 2015
1245‐1400 hrs
Lehman Building Room 272

ABSTRACT:
Writing, storing, moving and post‐processing vast unsteady datasets can interfere with an engineer’s interpretation and reporting of results. This seminar will present ongoing research to develop new methods designed to extract and reduce large unsteady CFD derived volumetric data. In‐Situ data extraction whereby sub‐setting and segmenting the volume data using data extraction and analysis libraries directly integrated within the solver codes themselves is the first step. To further reduce the amount of unsteady CFD extract data written to disk, methods such as Proper Orthogonal Decomposition may be used to reconstructed the solution data within a given error band. This seminar will present preliminary research and how the CFD could use these techniques to analyze their large‐scale CFD solutions.

 

Duque_headshotBIO: Dr. Duque manages the Applied Research Group at Intelligent Light, the makers of the leading CFD  post‐processing software FieldView. Previous to Intelligent Light, he was a tenured Professor of Mechanical Engineering at Northern Arizona University. Prior to his time at the university, he was a Research Scientist for the Army’s Rotorcraft CFD Applications Group located at the Numerical Aerodynamic Simulation Facility at NASA Ames Research Center. His current research focuses upon the development of large scale data management techniques for multi‐physics simulations. He has been awarded the Lichten Medal from the American Helicopter Society for his pioneering CFD studies on the BERP helicopter rotors, the Army Superior Civilian Service Medal for his lead role in the use of CFD to study and alleviate vibratory load problems on the Apache‐Longbow and Comanche Helicopters and is an Associate Fellow of the AIAA.

Roger Rintala

No Compromise CFD with On-Demand HPC

XDBview logoThe accessibility of HPC via cloud computing offers tremendous flexibility for CFD users with peak workload demands as well as for organizations and consultants who do not maintain HPC systems in house.

 

By designing a CFD workflow that maximizes the use of HPC systems and eliminates the transfer of volume data sets, productivity gains can be tremendous.  The ability to run high resolution, time dependent simulations and full suites of design points allow every idea to be thoroughly vetted.  Intelligent Light sponsored research used this approach to help a single researcher perform over 60 simulations and evaluate nearly 3TB of data for the AIAA High Lift Prediction Workshop.  Result files were post-processed remotely and only compact XDB files were transferred to the user’s local workstation.

 

Learn how this was accomplished and see how this approach can make your CFD workflow more capable and productive.

 

Roger Rintala

In-situ XDB Workflow Allows Coupling of CFD to Flight Simulator for Ship Airwake/Helicopter Interaction

Big Data, Big Challenge

 

Capturing helicopter interactions with a ship’s airwake in flight simulation made possible with in-situ XDB workflow.

CREATE_AV_CASTLE_

An image from work described in “Coupled Flight Simulator and CFD Calculations of Ship Airwake using HPCMP CREATE™–AV Kestrel”, James R. Forsythe et al, AIAA 2015-0556. Disclaimer: The US Government and Dept. of the Navy do not endorse products or services.

The CREATE™–AV team undertook a simulation challenge last year: coupling the CFD solver HPCMP CREATE–AV Kestrel to the Navy flight simulator CASTLE® for a fully coupled rotorcraft simulation in a ship’s airwake. While high-fidelity ship airwake simulation data has been used with helicopter landing simulations, it had been based on queries of a static database.  This project marks the first time that the flight simulation system has incorporated helicopter and ship airwake interactions into the simulation.  Capturing the important interactions results in much higher realism and training quality.

 

Intelligent Light provided software and expertise to solve extraordinary challenges presented by the size of the data, the need to move it quickly, and to process and visulize the results.  Intractable with traditional CFD workflows, Intelligent Light’s unique In-situ XDB workflow solved the problem.

 

The approach, hover and landing sequence had a simulation duration of 45 seconds. The time to save, transfer and read these visualization files along with the massive space required to save them emerged as a significant roadblock to success.

 

In-situ XDB Workflow via VisIt/libsim provided the solution. The CREATE–AV team, aided by Intelligent Light, integrated VisIt’s in-situ post-processing library libsim into Kestrel. The resulting workflow created and saved FieldView XDBs (extract databases) as the simulation ran on the HPC resource. FieldView was then used for all visual flight checks and movie generation, without the burden of dealing with the volume grid and results.

“The long time-scales and high frequency content due to the blade motion made visualization a challenge, so an ability to create feature extracts was created using VisIt libsim’s capability to extract FieldView13 xdb files. This enabled the creation of animations at a physical resolution of 60Hz (every five iterations) over the 45 seconds simulated. The resulting 2700 extracts were post-processed using FieldView in batch and in parallel to render the animations in a few hours rather than the days it would have otherwise taken. This capability should be in a future release of Kestrel.”

- J. Forsythe, C. Lynch, S. Polsky, and P. Spalart, “Coupled Flight Simulator and CFD Calculations of Ship Airwake using HPCMP CREATE™-AV Kestrel“,

AIAA paper 2015-0556

See AIAA 2015-0556 for details and acknowledgements.