DESIGN FEATURES AND OPERATIONAL CHARACTERISTICS OF THE LANGLEY 0.3-METER TRANSONIC CRYOGENIC TUNNEL

摘要

Experience with the Langley 0.3-meter transonic cryogenic tunnel, which is fan driven, indicates that such a tunnel presents no unusual design difficulties and is simple to operate. In addition, purging, cooldown, and warmup times are acceptable and can be predicted with good accuracy. Cooling with liquid nitrogen is practical over a wide range of operating conditions at power levels required for transonic testing, and good temperature distributions are obtained by using a simple liquid-nitrogen injection system.nTo take full advantage of the unique Reynolds number capabilities of the 0.3-meter transonic tunnel, it has been designed to accommodate test sections other than the original, octagonal, three-dimensional test section. A 20- by 60-cm two-dimensional test section has recently been installed and is being calibrated. A two-dimensional test section with self-streamlining walls and a test section incor¬porating a magnetic suspension and balance system are being considered.