RE: [T3] too much mind time (advanced intro to applied mechanics :-)

["Erkson, Toby" <toby.erkson@intel.com>]

Lemme see if I have this right.  Since I'm a male and considered an engineer
I'll use a semi-visual :)

              Pressure Wave and Direction
Time Period         Valve   Plenum
     1                  H -->
     2                  L <--
     3                  L -->
     4                  H <--

Is this correct?  Why does the wave suddenly change direction in the plenum?
Why not continue it's travel to the OTHER valve?  And what effect is there
if this wave does continue to the other valve?  Why isn't the wave a high
pressure one in time period 3 and a low pressure one in time period 4 (I'm
thinking simple waves, like in a pond...shows my level of physics :)?  What
about the other pulses that are happening in the intake system, how do they
affect the others?  I have to go to the bathroom, are we there yet? :)

Lastly, for us wanna-be mechanical engineers, can you recommend any books
for us beginners, like Mechanical Engineering for Dummies?  :)  I have two
books on fastener technology (how screws, rivets and such work, where to
place them, figuring out torque, and other completely geeky stuff) but I
need more about material science and fluid, wave mechanics, thermodynamics,
etc. as well.

   Toby "I may look like a geek, but I am one...no, wait...duh-ooh!" Erkson
   air_cooled_nut@pobox.com
   '72 VW Squareback 1.6L bored and stroked to 2.0L, Berg five-speed
   '95 VW Jetta III GL 2.0L, P-Chipped, Jamex sport suspension
   Portland, Oregon, http://www.icbm.org/

>-----Original Message-----
>...
>The other factor in the idealization is that immediately after the intake
valve 
>sharply closes (thanks to our idealized "digital" cam :-), a pressure pulse
is 
>generated at the back side of the valve.  This "positive" (i.e. higher than

>mean plenum pressure) pulse travels to the plenum, is reversed, travels
back to 
>the valve as a "negative" (i.e. lower than mean plenum pressure) pulse, 
>reflects, travels back to the plenum and is reversed again, then travels
back 
>to the intake valve as a "positive" pressure pulse.  This scenario is what
I 
>termed the 1st harmonic.  The 2nd harmonic is when this sequence happens
twice 
>and the 3rd is thrice, etc. 

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