1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Contact pressure of piston rod onto a surface?

  1. May 5, 2015 #1
    I have two images below.

    This is a single piston with pressure inside, the variables are as listed.

    P_in = 2700 Pa.
    P_out = 0 Pa.
    R1 = Radius 1 = 10 cm.
    R2 = Radius 2 = 5 mm.
    P_contact = ?

    My solution to P_contact is as follows.

    Area A1 of piston at R1 = .0314m^2 and area A2 at R2 = 7.85x10^-5 m^2. The force exerted by P_in on the face of the piston with A1 is 84.78 N. Therefore P_contact = 84.78/ A2 = 1080000 Pa. I'm just wondering if this is correct?

    ?temp_hash=cf837626c0695dd932af5fd7aa30c911.png


    My second picture has a dual piston setup and my question is whether the P_contact variable on either side is halved?

    ?temp_hash=cf837626c0695dd932af5fd7aa30c911.png
     

    Attached Files:

  2. jcsd
  3. May 5, 2015 #2
    Assuming that the black area is a fluid, P_in will be the same as P_contact. The forces on the two sides will be different though.
     
  4. May 6, 2015 #3
    Oh no, forgot to mention the black area would be a solid like steel or something. The Pressure for P_in would be due to a gas like air and the grey area would be a solid too like steel or wood.
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook




Similar Discussions: Contact pressure of piston rod onto a surface?
Loading...