Rotor to stator port ratio?

[Justin]

Say I have a 4:4 rotor with a 10:12 port ratio stator...
Will this work as effectively as a 10:12 port rotor against a 10:12 stator?

For example, will one experience a decibel SPL drop because too much air is being let out at once?

Can speeding up the rotor motor help counter any sound pressure loss?

[Robert Gift]

Regardless of how many openings the rotor has, it is the stator ports which determine how much air is released and when.

I wondered what would happen if one had a five opening rotor in a six port stator.

At a given moment, some rotor openings and stator ports would be aligned and expel air and chop it, while at other places in the circumference the rotor opening would be blocked.

So instead of air being released through all stators ports simultaneously, creating the greatest pulse of air, some air would be partially or completely blocked, so the SPL would be less.

Speeding up the rotor will pull in more air and increase the air pressure against the stator and increase the spl from the level produced by the less efficient mismatched opening to port ratio.

Would be fun to try!

[Justin]

Ok, thanks mate.

[Jim_Ferer]

Any mismatch between rotor and stator means a loss of efficiency and a lessening of the sound output.

[Daniel]

You may be able to get a bit more efficiency if you had, for example, a 10-12 rotor and a 5-6 stator with slots the width of one rotor port. This could increase air pressure through the ports. Then again, I've never experimented.

[Justin]

Yeah after thinking about it for a while, it made sense.

Thanks for your answers guys.

[Robert Gift]

Are any rotor stator assemblies made such that they are interchangeable?
It would be a fun experiment to calculate the difference, then measure the difference.

If it weren't so difficult, after tornado season I'd like to exchange the
rotors in the 2t22: 12-chamber rotor in the 10-port stator and 10-chamber rotor in the 12-port stator.

But I am afraid I may not get the rotors exactly on the shafts as they were - or am I being too cautious.

[Justin]

Are any rotor stator assemblies made such that they are interchangeable?

Wink wink, nudge nudge.

[AllSafe]

I think the only difference it would make to switch the rotors in a 2T22/3T22 would make is a slight variation in the harmonics resultant from chopping the air. It wouldn't change the pitch.

[Daniel]

Are any rotor stator assemblies made such that they are interchangeable?

Wink wink, nudge nudge.

Say no more!