Tunnel 9 completes Falcon Hypersonic Test Vehicle testing
By Philip Lorenz III
/ Published May 23, 2007
ARNOLD AIR FORCE BASE, TENN --
The U.S. Air Force's Arnold Engineering Development Center's (AEDC) Tunnel 9 facility in White Oak, Md. is playing a crucial role in the ongoing Falcon program, with the completion of mission-critical testing of the Hypersonic Technology Vehicle 1 (HTV-1).
The Falcon initiative is a joint Defense Advanced Research Projects Agency (DARPA) and Air Force program. The objective is to develop and demonstrate hypersonic technologies that will enable the capability to execute prompt global reach missions. The ultimate capability is envisioned to entail a reusable Hypersonic Cruise Vehicle (HCV) capable of delivering 12,000 pounds of payload a distance of 9,000 nautical miles in less than two hours. The technologies required by an HCV include high lift-to-drag technologies, high temperature materials, thermal protection systems, and guidance, navigation and control. A series of hypersonic technology vehicles (HTVs) are planned to incrementally demonstrate these required technologies in flight.
During the contracting stage of the program, three prime contractors specified requirements for pre-flight testing at AEDC (specifically in the ARC Heater Test Facility and VKF Tunnels B & C as well as Tunnel 9). Lockheed Martin won the contract and began their program. Early in the planning for the HTV-1 experiment it became clear that Computational Fluid Dynamics (CFD) modeling should be validated with highly accurate ground test data. Tunnel 9 alone provided the match of test conditions and data accuracy needed to make the program successful, according to Dan Marren, Tunnel 9 site director.
The Air Force Research Laboratory Air Vehicles (AFRL) Directorate at Wright Patterson Air Force Base, Ohio, provides technical guidance for the Falcon program to DARPA.
During program technical reviews, AFRL suggested that the program could be enhanced by the inclusion of data from AEDC Hypervelocity Wind Tunnel 9.
The AFRL Air Vehicles Scientific Advisor Dr. Peter Erbland, stated, "The Tunnel 9 facility exactly duplicates the HTV-1 flight Reynolds number at Mach 10, and the large model size permits accurate flow field resolution...Tunnel 9 will provide the best quality data and the best return on the investment of test dollars and effort."
More than 30 runs were successfully completed during this HTV-1 entry in AEDC Tunnel 9 at Mach 10 and 14. This data will help validate the aerodynamic data base at two important flight points prior to the upcoming critical design review.
"DARPA program management placed wind tunnel verification of HTV-1's aerodynamic properties on the top of their priority list," said 1st Lt. Ben Berlin, from the Air Force Falcon program office. "Not only did Tunnel 9 provide a unique and cost-effective means to perform this extremely valuable testing, Tunnel 9 finished testing ahead of schedule in order to provide this crucial data to Lockheed Martin prior to their critical design review.
"Working with AEDC Tunnel 9 personnel has been a true pleasure because they exemplify dedication and professionalism."
According to DARPA officials, the goal of the joint program is to develop and validate in-flight technologies that enable both a near-term (2010) and far-term (2025) capability to execute time-critical, prompt global-reach missions, while at the same time demonstrating affordable and responsive space lift.
The success of this effort extends past the boundaries of the Falcon program alone as evidenced by comments from the Air Force Chief Scientist Dr. Mark Lewis who stated, "This was an excellent linking of modeling and simulation, analysis and testing. AEDC contributed significant resources and technical expertise to the effort and this will almost certainly prove to be a definitive data set for both code validation and boundary-layer analysis."