Testing a steam whistle on Air

[GreensandsParticipant @greensands]

Hi – Is it practical to test a whistle constructed for a miniature steam locomotive by using air in place of steam? The design I am experimenting  with is one based upon that published in a recent ME  and the results when tested around 50psi have been disappointing, the sound issuing from the tube being more one of escaping air rather than a musical note. I also note that this particular design uses a double slot as opposed to the more usual single slot. Any views and comments would be very welcomed.

[roy entwistleParticipant @royentwistle24699]

You cannot test a steam whistle on air as far as I know

Roy

[norm nortonParticipant @normnorton75434]

A whistle that sounds fine on steam will blow fine on air, but at a slightly different pitch. Conversely, a whistle that works on air will not necessarily sound right on steam. I say this from my limited trial and error experiments.

I think it is because under steam there is more energy being inserted (higher viscosity, temperature?) and the whistle that was OK on air will now have a whole set of additional harmonics that sound like the trodden-on cat.

Norm

[noel shelleyParticipant @noelshelley55608]

I’m with Norm on this, it should work but at a different pitch.  Pressure will have a bearing on the matter to. Noel.

[Clive Brown 1Participant @clivebrown1]

LBSC’s “Shop Shed and Road” has a good chapter on whistles of various types. Tuning of chime whistles on air is described. The need for fairly high pressure is mentioned; ie 60+ psi.

[Speedy Builder5Participant @speedybuilder5]

The whistle I made for SPEEDY 5″ loco works well on steam, air and human breath. I made it from a section of tube taken from a trumpet that had been “trampled on”.

[Author]

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