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A team led by The Johns Hopkins University Applied Physics Laboratory (APL), in Laurel, Md., successfully conducted the first-ever ground test of a full-scale, fully integrated hypersonic cruise missile engine using conventional liquid hydrocarbon fuel, May 30, at NASA Langley Research Center in Virginia.
The APL-invented Dual Combustion Ramjet (DCR) engine concept being tested forms the basis for a hypersonic strike missile concept being developed under the newly initiated Hypersonic Flight (HyFly) Demonstration Program - a joint effort between DARPA (Defense Advanced Research Projects Agency) and ONR (Office of Naval Research). HyFly is aimed at flying a high-speed, long-range hypersonic air-breathing test vehicle. Such technology could be used to develop a future high-speed strike weapon to engage and defeat time-critical, heavily defended, hardened or buried targets while keeping forces farther from harm.
The May 30th test, simulating realistic cruise conditions for a hypersonic vehicle operating at 90,000 feet at a speed of Mach 6.5, demonstrated robust engine operation. It's the first in a series of tests to fully characterize the engine's performance at speeds of Mach 6.0 and above. Tests later this summer, at the Arnold Engineering Development Center (AEDC) in Tennessee, will verify operation at Mach 3.5-4.0 flight conditions simulating takeover after a rocket boost.
"This is the first time a full-scale, scramjet missile engine has been tested with conventional, liquid hydrocarbon fuel where the complete engine flowpath is fully installed in a missile configuration. This has enabled us to measure for the first time net positive thrust for an installed hydrocarbon fueled scramjet engine. This is a major milestone for the hypersonic community and it's the product of a real team effort between DARPA, ONR, APL, Boeing, Aerojet and NASA," says Mike White, APL program area manager for Advanced Vehicle Technologies. "APL conducted combustor developmental testing and worked with Boeing to refine the DCR inlet design. Aerojet built the freejet engine we're now testing. Our current freejet tests are the transition element between ground-test development performed under the ONR Hypersonic Weapon Technology Program and the joint HyFly flight demonstration program." Boeing and Aerojet have now taken over responsibility for the DCR flight demonstrator under HyFly.
"The dual combustion ramjet engine concept is the enabling technology for a future high-speed strike weapon," according to a joint statement, included within a DARPA press release announcing the test, issued by Rear Adm. Jay Cohen, chief of Naval Research and Dr. Tony Tether, director of DARPA. "A hypersonic strike weapon has the potential to transform our nation's armed forces to meet future warfighting needs. HyFly is a leading element of DoD's National Aerospace Initiative to demonstrate advanced hypersonic technologies."
Earlier this fiscal year, DARPA and ONR joined forces in the four-year HyFly program to demonstrate, in flight, a missile concept capable of flying at speeds up to Mach 6.5 at ranges of 600 nautical miles using liquid hydrocarbon fuels, which are non-toxic and safe to carry aboard ships. The missile concept being developed can also cruise at Mach 4.0, extending the range to over 800 nautical miles.
Current testing verifies very robust, high performance Mach 6.5 operation of the engine using room-temperature, liquid JP-10 fuel. "The engine test just completed demonstrated robust engine operation over a broad range of fuel flows that transitioned the engine from supersonic combustion to dual-mode combustion operation during this single test," says Don Messit, Aerojet's lead propulsion engineer for DCR. "The JP-10 fuel we are using for DCR is the same fuel that is currently used in the Tomahawk cruise missile and already approved for shipboard use," according to Gil Graff, ONR program manager for Weapon Technology and deputy program manager for HyFly.
Development of the DCR engine concept continues through 2002 with freejet engine tests and complementary direct-connect combustor tests at APL's Avery Advanced Technology Development Laboratory. "We're continuing to conduct full-scale, direct-connect combustor tests in parallel with the freejet tests to obtain a more complete picture of the total engine performance," says Steve D'Alessio, APL's project manager for the DCR engine. "We've conducted over 100 runs simulating Mach 6.0-6.5 conditions in preparation for the freejet tests. We're now testing at conditions simulating Mach 3.0-4.0 in our direct-connect facility prior to testing the full-scale freejet model at AEDC later this summer."
Flight tests of HyFly's demonstrator vehicle will begin in late 2003 with demonstration of a surrogate submunition deployment in March 2004. Powered flights at Mach 4.0 will begin in November 2004 and at Mach 6.0 a year later. A total of 11 flights (eight will be powered) will be conducted in a "fly early, fly often" program approach geared toward managing risk while achieving program performance goals.
As lead technical agent for DARPA and ONR throughout this program, APL provides technical advisory support to program management and to the government and industry team executing the program. "APL has nearly a 60-year heritage in the development of high-speed guided-missile technology," says White. "We're applying our long-term expertise in this area to help a team of government and industry experts succeed in transitioning this technology to industry for development of a high-speed strike weapon."
The Applied Physics Laboratory, a division of The Johns Hopkins University, meets critical national challenges through the innovative application of science and technology. For more information, visit http://www.jhuapl.edu.