An Analysis of Alternatives to Provide a Varying Mach Number Test Capability at APTU

The Aerodynamic and Propulsion Test Unit at the Arnold Engineering Development Center began a series of major upgrades in 2002 to provide a ground-test capability for high-speed/hypersonic air-breathing propulsion systems up to near Mach 8. The next major phase of the upgrade program, started in 2005, will add a varying Mach number test capability by 2011. The Hypersonic Propulsion Test Capability project will procure a flexible wall freejet nozzle and install it in the test facility with the requirement to vary the Mach number from as low as Mach 2 to above Mach 5 at simulated flight conditions of interest to the air-breathing propulsion industry. An Analysis of Alternatives methodology was used to quantitatively determine the best solution to the problem of varying the Mach number in a high-speed and hypersonic test facility. This paper describes the decision analysis process used for the study and discusses the various MUST and WANT objectives chosen to guide the decision process. The various approaches to providing the varying Mach number test capability are also described.