How can I scale down a propeller for wind tunnel testing? I want to scale down my propeller for a wind tunnel testing. But I am unable to find any literature on it.  Please give suggestions.
The airfoil of the propeller should not change with size if you are scaling it up and down. As long as the airfoil is the same and the proportions are correct relative to both propellers (length, chord, pitch, etc.) that should be all you need to pay attention to.