Renovated rocket lab at Purdue is ‘national resource’

WEST LAFAYETTE, Ind. — Purdue University has completed major renovations to a
one-of-a-kind propulsion facility and has begun full-scale laboratory testing in
research that includes work to develop engines for NASA’s next-generation space
shuttle.

Engineers working in the High Pressure Laboratory, one of six facilities at
Purdue’s Maurice J. Zucrow Laboratories, will perform research sponsored by the
National Aeronautics and Space Administration, U.S. Air Force and U.S. Army,
other federal agencies and aerospace companies, said Stephen Heister, a
professor in Purdue’s School of Aeronautics and Astronautics.

"It’s the most comprehensive and most capable university propulsion facility in
which to test engines at higher pressures and thrust levels," said Heister, who
has led efforts to refurbish the lab.

Rocket tests began in June.

"This lab truly will become a national resource because of its scale and
capabilities," said William Anderson, an associate professor of aeronautics and
astronautics. "We will be able to study physical phenomena on the scale and
conditions at which they occur in real rockets."

The lab will be an important training ground for a new generation of engineers,
who will be essential for the nation’s space industry to meet its goals,
Anderson said.

"It is well recognized that there is a critical need for new grads as the
engineers who began their careers in the ’60s retire," he said. "By the time our
students begin their professional careers, they will already have seen their
designs transformed into experimental hardware and see how their analyses
compare to actual results. NASA and industry realize this, and they have been
very supportive of our efforts to build up this lab, and we are very
appreciative of their support."

The rocket-testing facility within the High Pressure Lab, built in 1965, had not
been upgraded since the mid-1970s. Jay Gore, the Vincent P. Reilly Professor of
Mechanical Engineering and Associate Dean of Engineering for Research and
Entrepreneurship, said in the interim, other, more modern portions of the lab
have been active in combustion research for turbine engines used in aircraft and
power generation and in work to improve diesel engines for trucks and other
vehicles.

Purdue began rebuilding the lab two years ago, when it received a $1 million,
two-year grant from the Indiana 21st Century Research and Technology Fund,
established by the state to promote high-tech research and development and to
help commercialize university innovations. That work, which established the lab
as the Indiana Propulsion and Power Center of Excellence, was carried out with
help from the Allison Advanced Development Co. in Indianapolis, a division of
Rolls-Royce Corp.

The renovated lab has already begun attracting research dollars.

"Over those two years that Purdue received $1 million, we brought in almost $3
million in research money, so we leveraged that money quite well," said Scott E.
Meyer, senior propulsion engineer at the lab.

The high-pressure lab includes two "test cells," blockhouse-like rooms with
18-inch-thick steel-reinforced concrete walls. Each cell contains two test beds,
meaning four separate tests can be carried out at the same time.

One of the cells is for rocket testing. The other is for combustion research for
turbine engines and for work in experimental propulsion systems such as
"pulse-detonation" engines. These engines may lead to the development of
"hypersonic" aircraft that travel several times the speed of sound. The advanced
military and commercial aircraft are expected not only to travel faster, but
also more efficiently and at lower cost than conventional jets.

The lab is jointly operated by the School of Mechanical Engineering and the
School of Aeronautics and Astronautics. Its namesake, Maurice J. Zucrow, was a
Purdue mechanical engineering alumnus who, in 1928, earned the first doctoral
degree in an engineering field granted by Purdue. His research in rocket
propulsion inspired the construction of the first facility at Zucrow Labs in
1948. Since then, the Zucrow labs have evolved into a complex of six facilities
on a 24-acre site west of campus, where engineers perform a wide range of
propulsion-related research in rockets, jet engines and other internal
combustion engines.

"Support from the 21st Century Research and Technology Fund made it possible to
inject new energy into the propulsion and power effort at Purdue, which is one
of our true legacies," said E. Daniel Hirleman, the William E. and Florence E.
Perry Head of the School of Mechanical Engineering.

A critical part of the lab is a system that pressurizes the rocket fuel before
feeding it to the test engines — a step that enables the facility to simulate
the real thing. The Purdue lab is believed to be the only university facility in
the nation capable of firing rockets with propellant-feed pressures up to 6,000
pounds per square inch and thrust levels up to 10,000 pounds of force, which are
typical conditions that exist in advanced chemical rocket engines.

Rockets use special turbopumps to inject fuel at high pressure into the
combustion chamber. In the lab setting, however, it is safer and more practical
to use high-pressure nitrogen to push the fuel into the engine instead of using
the turbopumps. Liquid nitrogen is held in a 2,400-gallon tank maintained at
about minus 300 degrees Fahrenheit. The nitrogen is vaporized and transferred
via metal tubing to holding tanks at pressures as high as 6,000 pounds per
square inch for use in the experiments. While the engines are running in the
test cells, data are collected by various sensors, and video cameras record the
firing.

Another unusual feature in the lab is a large tank, or "heat exchanger," in
which natural gas heats air to test pulse-detonation and jet engines. Unlike
rockets, jet turbines and pulse-detonation engines scoop air from the atmosphere
in order to burn fuel. In live flights, the air in such engines is heated to
hundreds of degrees. To simulate those operating conditions, air is artificially
heated with natural gas and then fed into the test cell.

"I think we are well positioned to really contribute to a lot of the high-speed
propulsion systems that are being developed because we have a large air supply,
and we can heat air to simulate high-speed flight conditions," Heister said.

Yet another factor that sets the Purdue lab apart from other university
facilities is that it was designed originally for rocket testing.

"Because most facilities were not built to do this kind of work, they are
landlocked on their campuses or limited in other ways," Meyer said. "This lab
was intentionally created to be remote from campus to be able to do this kind of
work."

Students are essential for the lab’s operation because they perform most of the
work, gaining valuable experience in the process.

"The students not only have to fulfill their rigorous course work, they also
come out here and do real engineering," Meyer said. "They do the lion’s share of
the work, running tubing and plumbing, doing the wiring, programming the
data-acquisition systems, hooking up instrumentation, conducting the test
operations."

Senior Kevin Miller of Goshen, Ind., said opportunities in the lab influenced
his decision to stay at Purdue for graduate studies.

"It’s extraordinary to have such firsthand exposure to all phases of a project,"
Miller said. "I chose to stay on for grad school because I am extremely excited
about the research that is being conducted here, and I feel that working in this
particular lab environment will enable me to develop rapidly as an engineer."

The first tests carried out in the refurbished lab were for Northrop Grumman
Space Technologies, which is developing rocket engines for a new generation of
space shuttles. Other work funded by NASA also will focus on testing engines for
future space shuttles.

"The high pressure lab has been an invaluable experience in terms of hands-on,
practical knowledge," said Adam Butt of Carmel, Ind., who is studying for a
master’s degree in aeronautics and astronautics. "Most engineers in the field
only work on one aspect of a system design. Here we have the opportunity not
only to design, but also to build, test, analyze, and redesign.

"It’s an amazing and rare opportunity."

Related Web site:

* Purdue School of Aeronautics and Astronautics Propulsion Web site
http://roger.ecn.purdue.edu/~propulsi/propulsion/