Can hot air replicate the sound effects of exhaust gases?

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Discussion Overview

The discussion centers on the possibility of replicating the sound effects produced by exhaust gases in cars using only hot air. Participants explore the implications of sound generation in electric vehicles compared to traditional internal combustion engine (ICE) vehicles, considering both aesthetic and safety aspects.

Discussion Character

  • Exploratory
  • Technical explanation
  • Debate/contested

Main Points Raised

  • Some participants question whether the goal is merely to create sound effects or to conduct a scientific test or experiment.
  • One participant suggests that replacing exhaust gases with air would alter the speed of sound, density, and acoustic impedance, but the differences may not be significant.
  • Another participant proposes harnessing heat from electric motors and batteries to produce sounds that mimic conventional ICE vehicles.
  • A suggestion is made that sounds could be generated electronically using loudspeakers, allowing customization of car sounds.
  • Concerns are raised about the relevance of the original question, with a focus on the pulsed gas flow of ICE exhaust compared to the continuous flow of cooling air in electric vehicles, which may not produce similar sounds.
  • One participant speculates that using a rotary blower with a cyclical bleed could create a pulsed airflow that might resonate in a tube, potentially mimicking exhaust sounds.

Areas of Agreement / Disagreement

Participants express differing views on the feasibility and methods of replicating exhaust sounds with hot air, indicating that multiple competing perspectives remain without a clear consensus.

Contextual Notes

There are unresolved assumptions regarding the acoustic properties of different gas compositions and the specific mechanisms by which sound could be generated in electric vehicles.

Khumo
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Hey guys, is it possible to replicate the sounds produced by exhaust gases in a car by using only hot air? Thanks in advance for your responses.
 
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Is this about just getting 'sound effects' or is it about some scientific test or experiment ?

Tell us more in any case .
 
Suppose we replace the exhaust gases by air. The composition is different, but both of them still contain mostly nitrogen. How does the speed of sound, the density and the acoustic impedance change if part of the oxygen is replaced by CO2 and H2O ? There will be differences in the acoustics, but it is probably not large.
 
Nidum said:
Is this about just getting 'sound effects' or is it about some scientific test or experiment ?

Tell us more in any case .
Nidum said:
Is this about just getting 'sound effects' or is it about some scientific test or experiment ?

Tell us more in any case .
Thanks for the responses, basically I wanted to know if it would be possible to harness the heat generated by electric motors & batteries and channel to produce sound so that electric cars would sound just like conventional IC engine cars.
 
You could generates the sounds in the passenger compartment electronically just using loudspeaker systems .

Nice idea in principle though . Anyone with a modern boring box on wheels could choose to program in their choice of car sounds .

Imagine a Mondeo that sounded like a race tuned 6 1/2 litre Blower Bentley .
 
I'm guessing that Khumo is less interested in esoteric aesthetic sounds than in road safety.
Porsche and VW cars have had air cooling for IC engines in the past, but I don't know if that produced much sound.
If these electric cars need some forced air cooling, maybe it could be made deliberately noisy without wasting to much power.
I think the original question is a bit off track, as the sound of IC engine exhaust has more to do with the pulsed gas flow forced by the IC process, than to do with the fact that the gases are hot or anything to do with their chemistry. Electric motors'cooling air would more likely come in a continuous stream with only turbulence noise. But if it were driven by a rotary blower, perhaps a small cyclical bleed - like old WW2 mechanical sirens - could produce a pulsed air flow to a resonant tube and matching horn?
 
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