🚀 go-pugleaf

In article <1992Nov6.214257.4807@ee.ubc.ca>, jmorriso@ee.ubc.ca (John Paul Morrison) writes:
|> In article <1992Nov6.185517.25840@mprgate.mpr.ca> vanderby@mprgate.mpr.ca (David Vanderbyl) writes:
|> >Actually, there is no corelation between engine size and allowable
|> >emissions in the air care tests.  This is because the measurements
|> >are ppm and %, the total volume of pollutants is irrelevant.
|> >
|> >(This, incidentally, is why a hole in your muffler cannot help
|> > you pass emissions testing.)
|> 
|> Depending on the shape of the hole, and its position, the exhaust gases
|> could easily, and conceivably create a vacuum, and suck in more air into
|> the hole, thus diluting the exhaust.
|> 
[ascii drawing deleted]
|> 
|> Air flows IN instead of out, as you  might assume.
|> 
|> The gas is moving at  a high velocity, and is therefore at a lower pressure,
|> which will suck in air.

If the gas was at a lower pressure (than atmospheric) nothing would ever flow
out of the exhaust pipe. Your argument seems to be based on the Bernoulli
equation, which does not apply to compressible gas flow.
 
|> >
|> >Dave.
|> -- 
|> __________________________________________________________________________
|>  John Paul Morrison                     |  
|>  University of British Columbia, Canada |  
|>  Electrical Engineering                 |   .sig file without a cause
|>  jmorriso@ee.ubc.ca              VE7JPM |  
|> ________________________________________|_________________________________

-- 
----------------------------------------------------------------------
Daniel Ouellet, Research Associate
Pulp and Paper Centre, University of British Columbia
2385 East Mall, Vancouver, BC, Canada V6T 1Z4
Tel:(604)822-8240   Fax:(604)822-8563   Email: daniel@ppc.ubc.ca