Manufacturing Process Maturation for Propulsion Technology: Structural Insulators

ABSTRACT:The Arnold Engineering Development Complex (AEDC) represents the nations largest aerospace ground test facilities and includes several wind tunnels that are unlike any other in the world.AEDC routinely provides aerodynamic and aerothermodynamic ground testing to evaluate aerodynamic and propulsion system performance under hypersonic conditions.Its facilities are used to test the flight and materials behavior of all atmospheric reentry vehicles, trans-atmospheric interceptors, and access-to-space flight systems.One of the more aggressive AEDC facilities is Hypervelocity Wind Tunnel No. 9 (Tunnel 9) located at White Oak, Maryland.Tunnel 9 provides aerodynamic simulation critical to hypersonic system and vehicle technologies. The Tunnel 9-unique storage heater supplies working fluid at pressures up to 1900 atmospheres and temperatures up to 3650R.The fluid can be used in four axisymmetric, contoured nozzles that operate at Mach 7, 8, 10 and 14 enabling test times on the order of seconds (0.5-15sec).The combination of operational range and large test cell results in the highest Reynolds number, largest scale ground test facility in the world.Tunnel 9 is capable of simultaneously collecting continuous force, moment, pressure, and heat transfer data during each run.Having the ability to test at flight matched Reynolds numbers provides a significant risk reduction for the design and evaluation of hypersonic systems.Because of the short run times, Tunnel 9 does not employ active cooling in the supply and throat area.Instead, it relies on high temperature materials and the heat sink capability of the design to survive the extreme pressures and temperatures.Additionally Tunnel 9 uses nitrogen as the working fluid to minimize oxidation and corrosion of hardware.The harsh environmental conditions in Tunnel 9 cause performance issues in the throat that are very similar to those found in rocket nozzles, so recently developed missile propulsion technology can be exploited. Based on a Missile Defense Agency (MDA) SBIR in which high temperature materials, fabrication technologies, and design methodologies were developed and demonstrated, the proposed program will develop Tunnel 9 components with improved performance and extended life capability, while also reducing facility operational cost. The overall goal of the program is to develop a prototype Mach 18 throat section for use in Tunnel 9 that incorporates improvements gained at Mach 14.The transition effort includes tasks of analysis and component design, fabrication, laboratory scale testing, and delivery of prototype throats that will continue to mature state of the art nozzle technologies.Materials Research & Design, Inc. (MR&D) and its team of Plasma Processes, Inc. (PPI), Exothermics, Inc., and Southern Research Institute (SoRI) proposes to develop these extended life, high Mach throats for AEDC wind tunnels.This technology will reduce facility costs, improve flow quality, increase service life of the throat hardware, and expand Tunnel 9 testing capabilities.BENEFIT:Based on the success of this program, the materials and design technology can be transitioned to other high energy wind tunnel hardware including AEDC facilities (arc heaters, ATPU, etc.) and the GASL hypersonic air breathing propulsion test cells.