In engineering, the critical Reynolds number for pipe flow is Re=2320. Does this value also apply to gas flow in pipes such as compressed air?
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In engineering, the critical Reynolds number for pipe flow is Re=2320. Does this also apply to gas flows such as compressed air? Is it related to the type of fluid?
I think it should not be applicable to gas flow such as compressed air； The critical Reynolds number Re=2320 for pipe flow applies to incompressible fluids; air and other gases are compressible fluids ； The critical Reynolds number is related to the type of fluid.
It can be used for estimation; keep in mind that the density also changes after air is compressed.
The boundary between turbulence and laminar flow is somewhat vague; the Re value generally ranges from 2300 to 4000, with different values applicable to various fluids. Moreover, many of the calculation formulas used in engineering are empirical or semi-empirical formulas, and the applicable range of these formulas specifies the value range for Re! For things such as the drag coefficient, etc., refer to the applicable range of formulas in the relevant manuals!