Smithsonian Report. 1955. - Hunsaker 



Plate 5 



1. The 14-foot test section of tlte Ames Unitary Plan wind tunnel. It is capable of operating 

 smoothly from subsonic speeds throuch the speed of sound to low supersonic values, a 

 region where conventional wind tunnels are not usable, owing to choking. The perforated 

 or slotted walls of the tunnel permit flow disturbances to pass through the open parts while 

 retaining sufficient solid area to guide the air uniformly past the model. Two other test 

 sections operate at speeds up to Mach No. 3.5. 



2. The NACA Lewis Laborator\''s new 10-by-lO-foot supersonic wind tuinu'l is used for 

 research of aircraft power plants. This tunnel is designed for speeds of Mach Nos. 2 

 to 3.5. 



