Image to right: The 8-Foot High Temperature Tunnel at NASA's Langley Research Center was the site for testing by Pratt & Whitney Rocketdyne (PWR) of their hypersonic Ground Demonstrator Engine No. 2. The hydrocarbon-fueled scramjet propulsion system was tested in Mach 5 conditions. Image credit: NASA Langley Research Center/Paul Bagby

The 8-Foot High Temperature Tunnel at NASA's Langley Research Center was the site of testing of Pratt Whitney Rocketdyne's (PWR) hypersonic Ground Demonstrator Engine No. 2 (GDE-2). According to the company, their tests were the first time that a closed-loop hydrocarbon-fueled scramjet propulsion system has been successfully tested at hypersonic conditions.

The PWR GDE-2 produced significant hypersonic data results during several test runs conducted at Mach 5 conditions in the tunnel, which can accommodate testing at speeds from Mach 4 to Mach 7. The engine used standard JP-7 fuel in a closed-loop configuration to both cool the engine hardware and to fuel the engine’s combustor.

The 8-Foot High Temperature Tunnel at Langley simulates true enthalpy at hypersonic flight conditions for testing advanced large-scale, flight-weight aerothermal, structural, and propulsion concepts. The open-jet test section is 8 ft in diameter and 12-ft long. The test section accommodates very large models, air-breathing hypersonic propulsion systems, and structural and thermal protection system (TPS) components.

Pratt & Whitney Rocketdyne teamed with NASA and the U.S. Air Force Research Laboratory (AFRL) to complete the testing of GDE-2. A government/industry team that includes AFRL, DARPA (Defense Advanced Research Projects Agency), NASA, PWR, and The Boeing Company will use technology demonstrated by GDE-2 to develop the propulsion system for the X-51A flight demonstration program, which will begin flight testing in 2008, according to PWR.