Goddard Space Flight Center, Greenbelt, Maryland 20771
ENGINEERING COLLOQUIUM
Monday, December 3, 2007 / 3:30 PM, Building 3 Auditorium
Thomas Jackson
"Power for a Space Plane: Developing the Hydrocarbon-Fuelled Scramjet Engine "
ABSTRACT -- The supersonic combustion ramjet (scramjet) engine has been under development at one level or another for nearly 60 years. The largest single scramjet development effort within the U.S. was the National Aerospace Plane (NASP) program, focused on a single stage, runway-to-space-insertion engine/vehicle concept. NASP ended in the mid-90’s without flying. More narrowly focused scramjet efforts have continued within NASA and the DOD. NASA’s Hyper-X vehicles successfully flew at Mach 7 and 10. Both were hydrogen fuelled and of heat-sink construction. Their fuel volume and thermal management plan limited the duration of the powered portion of the flight to seconds. The Air Force is well into the X-51 Scramjet Engine Demonstration program with first flight to occur in 2009. Ground tests of the full-scale, flight-like hardware are 50% complete. The Air Force scramjet technology is centered on an actively cooled, hydrocarbon-fuelled engine. Test flights are planned for several minutes. The scramjet powered X-51 will accelerate over two Mach numbers and will maintain thermal balance during the entire powered portion of the flight. Critical technologies are the fixed geometry engine flowpath, designed for operation from Mach 4.5 to 6.5; the fuel management system which relies on a well controlled, endothermic cracking of the fuel within the engine heat exchanger as the core of the thermal management strategy; and, un-cooled, high temperature materials to complement the actively cooled portion of the engine/vehicle structure. These technologies are discussed, as well as future science and technology needs required to mature scramjet engine technology and broaden its utility – eventually, perhaps, to the original NASP concept.
SPEAKER -- Thomas Jackson is a Principal Engineer assigned to the Propulsion Directorate of the Air Force Research Laboratory. His primary responsibility is development of hydrocarbon-fuelled Scramjet propulsion technology. Dr. Jackson received his B.S. degree in Aerospace Engineering from the University of Cincinnati, his M.S. degree in the same discipline from the University of Dayton, and his Ph.D. degree in Mechanical Engineering from the University of California at Irvine. For his first 15 years in propulsion R&D he worked gas turbine engine technology, primarily in the areas of combustion of alternative hydrocarbon fuels and fuel injection systems. After receiving a Masters Degree in the Management of Technology from the Sloan School of the Massachusetts Institute of Technology, Dr. Jackson managed the mechanical systems area within the Propulsion Directorate in the early 90’s. He then assumed his current position of Deputy for Science in the Aerospace Propulsion Division of AFRL.