On Thu, 6 Jan 2005 04:21:19 -0800, "Ed Price" wrote:

OTOH, Boeing didn't go from the computer model directly to production.

Hi Ed,

That is arguably the goal if not the actual reality:

"As computers have become faster and more powerful in recent years,
we have been able to do a better job in modeling the entire airplane and
predicting the three-dimensional effects of the airflow around it,"
Cogan said. "The codes we have developed allow us to look at more
potential design options faster than ever before."

Indeed, Cogan said the process for developing airplanes today begins
with the computer model. The coding is so accurate that designers can
evaluate miniscule changes in a design to determine impacts on
aerodynamic efficiency, he added.

In fact, the accuracy of the coding has also focused the application of
another aerodynamics tool: wind tunnel testing.

In the '80s, the Boeing 767 team took more than 50 wing designs into
the wind tunnel to verify their designs, Cogan said. In the '90s, the
Boeing 777 team took 18 designs into the tunnel. "We were really not
verifying the designs as much as we were verifying that our computation
tools were accurate and looking at performance at the extreme operating
conditions, which the coding couldn't do," Cogan said.

"With the 7E7, we will take fewer than 12 wings into the tunnel," Cogan said.
"We are still proving our coding and testing the extremes.
The tunnel is a great tool but it's not very cost-effective.
So, being able to really focus on a few designs to get the data we need
is helping us be more cost-effective."

73's from Jet City,
Richard Clark, KB7QHC