• The Ames 11 Ft. Transonic Wind Tunnel is now back in service after a lengthy modernization project. Many old systems were renovated, but some significant improvements were also made. Modern digital control systems for the tunnel and model support control provide increased accuracy and speed. Several new flow elements were added to the circuit that improve flow quality. The baseline turbulence level has been reduced from 0.33% to 0.24% with a further reduction to 0.17% when all test section slots are covered. A vortex near the test section centerline has essentially been eliminated and local flow angularities have been reduced from 0.6 degrees to < 0.1 degrees.
	• Non-invasive flow techniques are available for customers of NASA/Ames wind tunnels. Pressure and temperature sensitive paint are commonly used in our facilities. Two laser velocimetry techniques (PIV and DGV) have been extensively used and are available with advance notice. A prototype liquid crystal technique for visualization of surface shear stresses can also be used with advance notice.
	• NASA/Ames wind tunnels measure model surface pressures using electronically scanned pressure modules from PSI Corporation. We are currently converting our inventory of pressure modules to Digitally Temperature Compensated (DTC) modules and have already seen dramatic improvements in productivity and data quality from the use of these new modules. The advantages of the DTC modules include: • Less system noise due to on-board digitizing and a fiber optic data link. • A simpler electrical installation. • A smaller wire and tubing bundle required to bridge across the internal balance. • Less drift and fewer calibrations. • Higher system bandwidth which allow longer measurement settling time improving data quality.