Views from Intelligent Light
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.

Yves-Marie Lefebvre

ANSYS® Fluent® 16.0 Enables FieldView HPC Capabilities

FieldView Parallel Export from ANSYS® Fluent® 16.0

 

ANSYS Fluent 16.0 provides the capability to export results to FV-UNS while maintaining the partitioning established for a FLUENT parallel solution.  The file is fully compatible with FieldView Parallel allowing for the substantial time savings from parallel processing.  Every FieldView license will support at least 8 processor cores.  FieldView Parallel will readily scale to 64 processors and beyond.  The export files can be automatically generated during the solver run.

 

Surface Export – From the ANSYS Fluent TUI a new option called “fieldview-unstruct-surfaces” creates a surface only FV-UNS export, where the user selects the exported surfaces from a list of boundary conditions and post-processing surfaces (iso-surfaces, planes…).

  • Surface export for Parallel FieldView – A surface export made from a parallel session of Fluent will maintain the partitioning of the surfaces, and the resulting file can thus be read in parallel by FieldView.
  • Interior surfaces may be selected for export in Fluent 16.0.  This is a longstanding request and is useful in applications like integrating flow rate or seeding streamlines on control surfaces.  Please contact our support team for information about how to use this new feature.

FieldView and FLUENT – Power for Unsteady Simulations

 

Unsteady simulations are often post-processed and reviewed using FieldView XDB files which are a fraction of the size of volume data.  Exporting surface data, reading into FieldView Parallel and then having FieldView post-process and produce XDB files can be entirely automated.  This workflow delivers lightweight XDB files for review in FieldView or by the free XDBview reader. When exporting from ANSYS FLUENT, the resulting file can be read into FieldView in parallel, dramatically reducing the read-in time.

Choose the right export for your data:  Quick Start – Working with FLUENT16 data in FieldView (PDF)

Roger Rintala

VisIt and FieldView HPC – DOE Highlights In-Situ

Visualizing Success: SBIRs Move Software into the Field

Visualizing Success: SBIRs Moving Software into the Field

Visualizing Success: SBIRs Move Software into the Field

 

Read the DOE Case Study

 

Intelligent Light is using SBIR grants to tap the
power of VisIt, a visualization program supported in
part by the Advanced Scientific Computing Research (ASCR) program in the Department of Energy (DOE) Office of Science.

 

Intelligent Light was selected as a trusted vendor who could provide the expertise and discipline to tailor tools to industrial workflows while commercializing and hardening the government developed code.  Intelligent Light is providing industrial grade software development, engineering service and customer support to end users.

 

The project enables Intelligent Light to hold down development cost and end-user investments by utilizing open source code developed by DOE.  Moreover, the project is helping Intelligent Light customers move to in-situ post-processing years earlier than if IL had developed all of the required technology from scratch.

 

Eric Brugger and other Lawrence Livermore National Laboratory scientists designed VisIt to visualize the mounds of simulation data DOE supercomputers generate. It’s built to scale well and it’s well suited for in situ processing.

 

“VisIt … is an open-source code, free to download and modify, as thousands of researchers have. With no licensing fees, merging VisIt into FieldView will hold
down costs for small- and medium-sized companies using it on HPC systems.”

Intelligent Light responded to a call by ASCR to harden and commercialize DOE-supported software for high performance computing applications, making the tools robust and accessible.  Working under a Phase II grant of nearly $1 million, Intelligent light is integrating VisIt into our FieldView HPC suite. The funding is from a U.S. Small Business
Innovation Research (SBIR) program, which provides capital for early research and development with commercial potential.

 

VisIt’s big-data capacity allows FieldView to handle a wider range of CFD visualization tasks. “But ‘if you want to turn it into a commercial product, you really have to spend the time to customize things to people’s workflows,’ Brugger says. ‘We’ve customized it to our workflows in the DOE community,’ but it doesn’t always fit other users workflows.”

 

ASCR recognized it needs help to move VisIt and other DOE-supported solutions for high-performance computing into commercial use. Through the SBIR program, it called
for small businesses able to take DOE codes and “shrink wrap” them into accessible tools.

 

The collaboration “shows DOE is taking its research and development and spawning new technology – which is one of our missions,” says Benjamin Grover, division leader for
Applications, Simulations, and Quality at Livermore.

 

With a Phase II grant of nearly $1 million, Intelligent Light is integrating VisIt into its FieldView HPC suite. Later this year, customers will be able to choose either the standard FieldView code or VisIt to visualize CFD data.

 

Read the DOE Case Study