An intensive analysis of a specific rocket engine design that promises high performance, longevity, and low cost is called for in a $175,000 sub-contract recently awarded to The University of Tennessee Space Institute.
ORBITEC’s innovative vortex combustion
rocket engine – labeled the Cool-Wall Vortex Combustion
Chamber (CWVCC) -- confines the mixing and burning of
propellants to the inner region of a whirling flow
field, preventing heat damage to the chamber.
“The outer region of the flow field prevents hot
combustion products from contacting the chamber wall,”
Dr. Joe Majdalani, UTSI professor and principal
investigator for the contract with the Wisconsin firm,
said. “While the chamber walls are subject to the
radiant heat transfer, one of the propellants provides
effective wall cooling to prevent heat from damaging the
chamber.”
The Cool-Wall design also results in minimal heat
cycling of the chamber walls, the Jack D. Whitfield
Professor of High Speed Flows said. “This extends the
lifetime of the chamber and allows for simple,
lightweight, low-cost engine designs.”
The ultimate goal of the project is to improve ORBITEC’s
computational and theoretical capabilities in modeling
heat transfer, lifetime, reusability, and
thrust-to-weight ratio for a liquid propelled rocket
engine, according to Majdalani. Further expected
benefits include simplifying the manufacture of the
engine and lowering operational costs.
“Second and third generation launch vehicles will
benefit from an available computational model during
their developmental stages,” Majdalani said.
“Computational fluid dynamics provide a feasible method
for simulating combined-cycle engines, liquid propellant
rocket motors, and air-breathing engines such as ramjets
and scramjets.”
The CWVCC concept can improve performance from
commercial and military perspectives, too, the professor
noted. Aside from the propulsive applications, he said
characterization of the vortex combustion field, with
minor changes, may have “significant benefits” in the
energy sector.
“For example,” Majdalani continued, “it could be applied
to swirl burners and furnaces that employ vortex
technology. It can also be applied to model gas and
hydrocyclone separators and de-dusters. Potential
results include improved combustion efficiency, extended
lifetime, and potentially reduced emissions.”
“Our theoretical study aims at better understanding the
fundamental behavior of cyclones and their inner
workings,” Majdalani added. “We also hope to better
understand and quantify the wall-cooling characteristics
attributed to cyclonic combustion.”
Since 1996, Majdalani has been engaged in a partnership
with ORBITEC.
The first NASA Phase II project was on the Vortex
Injection Hybrid Rocket Engine. Since that time, the
professor and his students have developed analytical
solutions that “capture the essence of the gaseous
motion inside the vortex-driven hybrid rockets.” They
have provided both theoretical solutions and numerically
simulated assessments to the first NASA/ORBITEC
vortex-driven liquid rocket engine.
“Now, our focus is switching to modeling an improved
version of the ORBITEC engines,” said Majdalani,
“including lab scale, full scale, and workhorse engines
sanctioned by the U.S. Air Force.”
Majdalani said his lengthy collaboration with Dr. Martin
J. Chiaverini, Principal Propulsion Engineer at ORBITEC,
“has enabled us to solve several problems of key
importance – specifically those pertaining to the vortex
engine development -- to ORBITEC, NASA, the U.S. Air
Force and Army. We are extremely grateful for Marty’s
efforts to support UTSI and for his contributions in
promoting vortex engine technology.” Chiaverini chairs
the Wisconsin Section of the American Institute of
Aeronautics and Astronautics and the AIAA Hybrid Rocket
Technical Committee.
DR. JOE MAJDALANI
Writer: Weldon Payne (931) 393-7222
wpayne@utsi.edu
