AUSTIN, Texas—Four University of Texas at Austin aerospace engineering professors have received a $5 million, five-year grant from the U.S. Air Force Office of Scientific Research to develop more efficient engine concepts for space vehicles.
“If we don’t improve the cost-efficiency of launching vehicles into space, we will never be able to take advantage of the potential that space offers for scientific, commercial and military applications,” said Dr. David Dolling, professor of aerospace engineering and the project’s principal investigator.
The engineers will seek to combine propulsion methods used in commercial airliners and advanced research-grade engines to create an engine that is the most efficient for each point in the flight through the earth’s atmosphere, until rocket engines take over to boost the vehicle into orbit. Such an engine would save fuel and reduce structural weight, Dolling said.
Engines use only one kind of “propulsion cycle”—a way of mixing fuel and oxidizer, combusting it and producing hot, high energy gas to propel the vehicle. Commercial aircraft, for example, use gas turbine cycles and a few supersonic systems use ramjet propulsion cycles, in which the speed of the vehicle is so high that the air is compressed in the intake without a mechanical compressor. In the future, aircraft may be propelled by “scramjet” cycles in which combustion of the fuel and oxidizer will occur at supersonic speeds. The scramjet cycle is most efficient at very high speeds. Each of these cycles provides optimal efficiency over a different range of speeds. By combining cycles, the engine maximizes its efficiency at all points in the flight.
Another benefit of combined-cycle engines is that they “breathe” air from the atmosphere directly, reducing significantly the weight of the vehicle. Space shuttles now must carry not only fuel but also oxygen, increasing their overall weight and the amount of fuel needed to propel them.
Other University of Texas at Austin aerospace engineers working with Dolling are Drs. Noel Clemens, Laxminarayan Raja and Maruthi Akella. The grant will be shared with a team of four professors from Stanford University, and they will all work closely with researchers from the U.S. Air Force.
For more information contact: Becky Rische, College of Engineering, 512-471-7272.
