Arnold Engineering Development Center teams provide NASA with test data (Forwarded)

Air Force Link
US Air Force

2/2/2007

Arnold teams provide NASA with test data
By Philip Lorenz III, Arnold Engineering Development Center

ARNOLD AIR FORCE BASE, Tenn. (AFNEWS) -- Two teams at the Engineering
Development Center's Hypervelocity Wind Tunnel 9 here were recently involved
in tests for NASA's next crew exploration vehicle.

One team made use of conventional and advanced measurement techniques during
the NASA-sponsored aerothermal testing on a scale model of the space
agency's new Orion, the projected spacecraft that will send a new generation
of explorers to the moon.

Orion is part of the Constellation Program to send human explorers to other
destinations in the solar system. Orion is scheduled to make a manned
mission no later than 2014 as the follow-on to the space shuttle, due to be
retired in 2010.

The test objective was to obtain heating data over the model's surface at
Mach 8 and 10 freestream conditions.

Unlike the development of the Apollo capsule, where the database was
populated entirely using experimental data, the Orion database is being
developed using advanced computational fluid dynamic techniques. The
experimental data will be used to validate the computational fluid dynamic
models for NASA's Orion database development.

The facility's unique high Mach number and high pressure capabilities
allowed NASA to obtain data on the vehicle, "which they were not able to
obtain in any other facility," said Joe Coblish, the project group team
leader at Tunnel 9.

A second Tunnel 9 team provided support by pushing the use of temperature
sensitive paint, or TSP, to its limits during the project's final phase. The
goal was to further develop and demonstrate TSP's effectiveness and
viability to collect test data in Tunnel 9's unique high-temperature and
high-pressure hypersonic environment.

TSP is a system that includes a special paint, an ultra-violet illumination
source and a sensitive charge coupled-device camera to obtain surface
temperature data. The paint is applied to the model in two layers -- a white
undercoat and the TSP layer. The white undercoat provides a uniform
reflective surface for the TSP. The illumination source excites the TSP
layer, which fluoresces a bright red color with its intensity inversely
proportional to the surface temperature on the model.

"TSP allows us to use what is described as a global mapping technique to get
the desired parameter -- heat transfer in this case -- from the entire
surface of the test article," said Joe Norris, Aerospace Testing Alliance's
TSP developmental lead at Tunnel 9. "It's effectively like acquiring data
from tens of thousands of thermocouples."

The team at Tunnel 9 had to deal with some technical challenges not
experienced at other facilities working with TSP and Pressure Sensitive
Paint, Mr. Norris said.

"Tunnel 9's unique combination of relatively short run times and high
heating rates presents challenges that are unique in the world of TSP/PSP,"
he said. "High-quality, high-output, stable illumination fields are needed
to combine with high-end, scientific-grade cameras to take images at frame
rates fast enough to calculate heat transfer."

IMAGE CAPTION:
[http://www.af.mil/shared/media/photo...-0000X-002.JPG
(22KB)]
Inna Kurits and Joe Norris examine the illuminated Temperature Sensitive
Paint coating on the NASA crew exploration vehicle model prior to a run Feb.
1 at Arnold Air Force Base, Tenn. Two teams at Arnold Engineering
Development Center's Hypervelocity Wind Tunnel 9 conducted tests for NASA's
next crew exploration vehicle. Ms. Kurits is a University of Maryland
graduate student and Mr. Norris is a Tunnel 9 project engineer. (U.S. Air
Force photo/Arnold Collier)