This Standard specifies such contents as terms, definitions, test method, and test rules of technical performance of meteorological low-speed wind tunnel (hereinafter referred to as wind tunnel).
This Standard is applicable to technical performance test of reversed flow type and direct-flow low-speed wind tunnel for meteorology newly manufactured, in use and after renovation with the upper limit velocity as 30 m/s. Meteorology wind tunnel performance with the upper limit velocity above 30 m/s may refer to this Standard.
2 Terms and Definitions
For the purposes of this Standard, the following terms and definitions apply.
2.1 Test section
The wind tunnel section for installation of instrument or standard instrument
2.2 Velocity range
The stable and available minimum (lower limit) to maximum (upper limit) velocity which may be reached within wind tunnel test section, the unit is meter per second (m/s).
2.3 Uniformity of velocity
The uniformity of air-flow velocity distributed on the same cross-section within wind tunnel test section which is expressed by the relative standard deviation of air-flow velocity at all points of cross profile within the wind tunnel test section.
2.4 Stability of velocity
The degree of the pulse of air velocity in the wind tunnel test section with time, represented with the ratio between the maximum value of velocity to average speed within specified time interval and the average speed.
2.5 Velocity ratio
The mean of the ratio between air-flow velocity of No.2 test section (or transition section) to that of No.1 test section (i.e. main test section) within the range of wind tunnel speed.
2.6 Deflection of air flow
The included angle between the airflow direction and the wind tunnel center within the test section of wind tunnel, the unit is degree (°).
2.7 Turbulence intensity
The dither degree existing relative to the air-flow velocity at any point in the wind tunnel test section, represented with the ratio of root mean square of pulse velocity to the average velocity.
2.8 Axial velocity gradient
