Calibration of the AEDC-PWT 16-Foot transonic tunnel aerodynamic test section at various Reynolds numbers /

Tests were conducted in the AEDC Propulsion Wind Tunnel (16T) to determine the tunnel test section Mach number distributions and calibration at various Reynolds numbers. Two separate test entries were made. Collectively, the calibration was conducted at Mach numbers from 0.2 to 1.6 and at Reynolds numbers from 500,000/ft to 6 million/ft. The calibration was conducted with the aerodynamic test section (Test Section 2) using a centerline pipe and/or wall pressure orifices to define the Mach number distributions. A quantitative evaluation of the effects of tunnel pressure ratio, test section wall angle, and Reynolds number on the tunnel Mach number distributions and calibration was accomplished. Results indicate that good quality Mach number distributions are obtained for both zero and the optimum wall angle schedule. To obtain the maximum accuracy, the Tunnel 16T calibration must be defined as a function of test section wall angle, Reynolds number, and Mach number. Comparison of this calibration with previous calibration results indicates that a revision in the tunnel calibration used for operations is desirable. Analytical expressions which represent the tunnel calibration at various test conditions were developed for use during Tunnel 16T operations.