3/12/02 -- Boeing Analyzes Sonic Cruiser Using NASA CFD Software
The Boeing Company is currently using an array of NASA-developed software packages to analyze different designs of their Sonic Cruiser airplane: the NASA Overset CFD Software (which includes the Overflow flow solver), Chimera Grid Tools, and Pegasus5.

As reported in the February 11, 2002 issue of Aviation Week and Space Technology (page 47), Boeing is extensively using computational fluid dynamics (CFD) to analyze the airplane's design, reducing the amount of wind tunnel testing needed.

Boeing plans to use only four high-speed wind tunnel testing sessions during the design of the Sonic Cruiser — two or three fewer sessions than would be required without the use of CFD. Fewer tests translates to significant savings of both time and money — a round of wind tunnel testing can take up to one year to complete.

“This represents significant cost savings to Boeing's multi-billion dollar Sonic Cruiser aircraft design effort. It will also mean that the aircraft will be able to enter service much sooner,” said Stuart Rogers, aerospace engineer and co-developer of Pegasus5, and the Chimera Grid Tools software, from the NASA Advanced Supercomputing (NAS) Division.

NASA Overset CFD software has been used to run hundreds of CFD calculations in the past year at Boeing. The high quality of the software, coupled with the automated CFD processes, makes it possible to turn around design test results quickly and accurately. "We had a lot of confidence in the CFD, and the first high-speed wind tunnel test results were very close to what CFD predicted," explained Walt Gillette, Boeing Sonic Cruiser program manager.

For additional information about NASA Overset CFD software, contact Stuart Rogers at rogers@nas.nasa.gov.

2/19/02 -- CFD Cycle Time Flies with Pegasus5 Software
Computational fluid dynamics (CFD) cycle time just got shorter with the newly improved Pegasus5 code. Co-developer Stuart Rogers, an aerospace engineer in the NAS Division at Ames Research Center, recently applied this code to a difficult and complex configuration -- a complete Boeing 777-200 high-lift aircraft.

Starting with an existing volume grids, Rogers was able to construct the entire overset grid-system in only three days -- a calculation that took 32 days to accomplish in 1998 using the previous version of the software, Pegasus4.

"This speedup in CFD cycle time and reduction in user expertise requirements will significantly reduce the cost of applying viscous CFD methods to complex design and analysis problems,” Rogers said.

The Pegasus5 software is used to perform the preprocessing task of linking together a large number of randomly overset grids. All that is required to use Pegasus5 is the OVERFLOW input file and the volume grids. During the past year, significant enhancements were made to the software, including algorithm improvements, bug fixes, and parallelization. It is these advances that enable Pegasus5 to perform calculations days sooner than Pegasus4.

Rogers plans to continue enhancements on the most recent version of Pegasus, making additional algorithm improvements to increase the code’s automation and robustness.
For more information on the Pegasus5 software, contact Stuart Rogers at rogers@nas.nasa.gov.