Pressure inside an ic engine

  1. Could some one tell me if there is any method to find out the instant pressure inside the combustion chamber of the internal combustion engine. I plan to change the way engines work if the pressure can be monitored.
     
  2. jcsd
  3. Danger

    Danger 9,878
    Gold Member

    Other than by calculation, I guess that the only way would be to mount transducers inside the cylinders or measure the force exerted on the connecting rod bearings.
    Brewnog does this sort of stuff for a living, so he might be the best person to answer this.
     
  4. i was thinking of using piezo electric crystals as the transducer in this case. Would they melt or be active at the temp and pressure acting inside the combustion chamber.
     
  5. brewnog

    brewnog 2,793
    Science Advisor
    Gold Member

    Yes you can use a piezo transducer, but you need one specially designed for combustion use, and you need a device capable of capturing the data at high speed and matching it to crankshaft angle from a rotary encoder.

    Try AVL or Kistler.
     
  6. could you suggest how this could be done
    i'm not trying to do it practically
    but only doing theoretical paper.
    so i need to explain the usage and not actually make it.
     
  7. i mean where can we get a piezoelectric transducer designed for such high temperature use. also let me know how to go about capturing the high speed data.
     
  8. brewnog

    brewnog 2,793
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    Gold Member

    What do you want to know? Put a pressure sensor in the cylinder, capture the signal using some kind of data acquisition kit, and link this to crankshaft angle from a rotary encoder.

    What's your question?
     
  9. I want to know what pressure sensor to use.
     
  10. brewnog

    brewnog 2,793
    Science Advisor
    Gold Member

    A piezoelectric dynamic pressure transducer?
     
  11. FredGarvin

    FredGarvin 5,087
    Science Advisor

    Look at Endevco's web site.
     
  12. can you give me the link please to this site.
     
  13. Danger

    Danger 9,878
    Gold Member

  14. sorry to have bothered you
    i'll rely on google more from now on
     
  15. Danger

    Danger 9,878
    Gold Member

    No bother. I was just pointing out that you need not rely upon others quite as much. You can learn much more by doing your own searches, since they can lead to multiple other related sites that might be beneficial.
     
  16. brewnog

    brewnog 2,793
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    Gold Member

    Nice link Fred. AVL and Kistler are the market leaders for reciprocating engine pressure measurement, I'll be sure to check out Endevco.
     
  17. actually even if i search, my ability to check out the correct links is less compared to an experts eyes. see all the links that you all post from nasa.
    i'm a regular visitor of www.nasa.gov but have never come across those links.
    just inexperienced i guess
     
  18. brewnog

    brewnog 2,793
    Science Advisor
    Gold Member

    I've never posted a Nasa link, just two which were pertinent to what I thought your question was.
     
  19. Try PCB Transducers, Also ussually internal combustion engines we do not speak of a combustion chamber since it is also a compression chamber etc.
    Most of the time only a couple cycles are tested this way one does not let the engine run for a long time. You will need high speed data capturing probably 1 Mhz temporal resolution (see Gagescope). That will give you about one datapoint per degree turning angle
     
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