The calculation and application of Reynolds number in <?A3B2 pi6?>cascade wind tunnel and experiment

The calculation formula of the Reynolds number in cascade testing was derived in detail using different viscosity calculation methods, including the index method and the Sutherland method. The relationship between characteristic parameters and the law of characteristic Reynolds number changing with Mach number was obtained. The Reynolds number per unit length (<italic>Re</italic>/ <italic>L</italic>) was suggested to be used as a universal characteristic parameter of wind tunnel Reynolds number. Finally, a method to confirm the modular size of a cascade and blade number based on the constraints of aspect ratio, Reynolds number, and vent height was proposed. The error range of Reynolds number calculation method of the cascade wind tunnel test is acceptable in engineering. And the method has important reference value in the fields of wind tunnel construction, cascade experiment, and modular design.