Can sound be used as energy to start & run car

[PRAVEEN58]

ADMINSTRATIVE NOTE: this topic has been split from another thread where it was out of topic.

 

QUESTION 1:-

 

can sound be used as energy to start & run car ?

instead of fuel such as petrol , diesel etc.

i m trying to reasearch on this but i cant find it eaisy

Edited November 15, 2010 by sanctus
off-topic elsewhere

[sanctus]

Sound is just pressure of the air, so you are asking if we can use pressure of air as a method of propulsion. So the answer is yes, but the question remains how effective that is...

[Qfwfq]

If you get the right ladies sitting inside, ya never know, a good enough transducer might even do the job...

/forums/images/smilies/banana_sign.gif

[CraigD]

Hi Singh! Welcome to hypography! :)

can sound be used as energy to start & run car ?

instead of fuel such as petrol , diesel etc.

In principle, yes, but to see if it can be practically done, a few approximate calculations are needed.

 

0 dB = 10^-12 W/m²

 

A typical noisy city street has a sound intensity of about 80 to 90 dB. 130 dB is painfully/hearing damagingly loud. A running jet engine at 30 m is about 150 dB, while the theoretically loudest sound there can be is about 190 dB.

 

A 2 m x 2 m x 4 m car (about a full-size van) has about 24 m² of surface area that could be covered with sound transducers (big speaker/microphones, essentially). So, assuming 100% efficiency, this big vehicle would receive less than 0.024 W from 90 dB ordinary road noise, 240 W from painfully loud 130 dB noise, 24000 W from the 150 dB near a jet engine.

 

240 W (about .32 horsepower) isn’t enough to move a car. 24000 W (about 32 HP) could, about as well as a vintage 1950s VW van.

 

So the scheme could, in principle, work, for low-speed vehicles in very loud environments. I don’t think it could be a practical replacement for ordinary, oil-burning cars and trucks.

 

See the wikipedia articles decibel and sound pressure for an overview of and references to the above calculations.