ARNOLD AIR FORCE BASE, TENN. – To meet development and testing needs for long-range strike and hypersonic vehicle materials, the H2 Arc Heater at AEDC has been upgraded, with checkouts being performed recently to ensure the modifications were successful. According to Harry Clark, AEDC senior engineer with the Strategic Plans and Test Facility Requirements, this project, known as the Mid-Pressure Arc Heater Prototype project or MPAH, has been a risk reduction effort that supports the Central Test and Evaluation Investment Program (CTEIP) project upgrading the H2 arc-jet test capability.
“The Test & Evaluation, Science & Technology branch of the Test Resource Management Center identified in 2014 the opportunity to ensure the success of the MPAH project by funding the installation of a segmented arc heater in H2 and demonstrating its performance envelope,” Clark said. “The project was funded in 2015 and has nine test conditions that comprise the Key Performance Parameter for the risk reduction effort. Successful demonstration of the KPP is required before the CTEIP project can proceed to execution.”
The facility modifications necessary to install the segmented heater in H2 were designed by AEDC engineers in 2015 and the fabrication was accomplished in 2016. Checkout of H2 began in the fall of last year, with the first KPP test condition demonstrated successfully in December. Two more KPP conditions were demonstrated before the end of 2016 and four of the remaining six were demonstrated last month.
“The AEDC design engineering team, the Model and Machine Shop team and the Arcs Test team deserve high praise for their efforts to take this project from concept to an operational first step toward a validated new test capability in just over two years,” Clark said.
As part of the upgrade, a state-of-the-art segmented heater is being placed in the H2 Arc Tunnel to replace the vintage Huels heater. The upgrade is necessary as hypersonic flight places extreme demands on vehicle structures and materials. Survivability testing of thermal protection system materials and structures for hypersonic environments requires high-temperature air flow with gas temperatures between approximately 4,500 degrees and 17,500 degrees Fahrenheit.
Arc heaters are able to meet this need by providing an efficient source for heating simulations, with realistic run times that are consistent with the time of many hypersonic flight missions.
Ted Myers, NAS project manager, also notes that the MPAH represents a significant operational capability upgrade to the AEDC arc jet test capabilities, which are unmatched by any in the world.
“Many folks have contributed to this accomplishment by personal sacrifice and long extensive work hours,” he said. “I take great pride in working with all the talented professionals that have made this happen, from technology, design, fabrication and installation work in the model shop and test facility to the ongoing successful checkouts being conducted by the facility test team. All was accomplished with no injuries to personnel.” The H2 Arc Tunnel was built from 1986 to 1988 as part of the Air Force consolidation of arc facilities at AEDC. It is one of three arc tunnels currently in use at the Complex.
DOD programs supported by H2 have included the Intercontinental Ballistic Missile, Navy Submarine-Launched Ballistic Missile, Defense Advanced Research Projects Agency (DARPA) Hypersonic Technology Vehicle 2 and HTV-3, DARPA Materials Development for Platforms, the Air Force Hypersonic Technology (HyTECH) Scramjet, multiple Army missile programs and Missile Defense Agency hypersonic interceptor programs. Civil and NASA programs supported include the Crew Exploration Vehicle, Mars Science Lab, Heat Shield for Extreme Entry Environments and Orion/Multi-Purpose Crew Vehicle.