Air Resonance Frequency: Effects of Excitation

[Mohamed_Wael]

I wonder of the air has resonance frequency or not, if yes what would happen if we excite it at this frequency

 

[Merlin3189]

The molecules in air, O₂ and N₂ both have many resonances, as do the minority constituents. For eg. both have resonances in the UV band and this provides some protection against UV radiation from the Sun. Oxygen has resonance in the region of 60GHz limiting the range of radio signals in this band.

There may be many others. Generally the effect is that radiation at resonant frequencies is absorbed and dissipated as heat or reradiated at lower frequencies.

 

[Mech_Engineer]

If you mean pressure wave resonance, this may be of interest to you: http://hyperphysics.phy-astr.gsu.edu/hbase/waves/opecol.html

The resonant frequencies of air columns depend upon the speed of sound in air as well as the length and geometry of the air column. Longitudinal pressure waves reflect from either closed or open ends to set up standing wave patterns. Important in the visualization of these standing waves is the location of the nodes and antinodes of pressure and displacement for the air in the columns.

 

[JBA]

Mech_Engineer, Your reference appears to me to also be an excellent reference for those investigating and trying to understand the mechanics of tuned intake and exhaust systems on engines.