I am trying to figure out the ideal fan axial placement on a dust blower. How far back should the fan wheel be. As close to the inlet side as possible seems logical, but too close may cause a siren effect. Or maybe air flow need a little extra room so long shaving do not jam up. Of course this is after the cyclone so shavings should not be an issue. This is for a standard sheet metal fan wheel with no extra shrouding attached to the wheel.
My google just gets me adds for confined space blowers.
Bill D