Now, with as many laws on the books for emmissions, and fuel economy, manufacturers must find a way to adhere to these laws.
Compression ratio (r)-
"The ratio of the volume of the cylinder when the piston is at the bottom of the cylinder (V2) to the volume when the piston is at the top (V1)." [1]
Where r = V2 / V1
The equation for the efficiency of this process is (n) = 1 - r^1-k
Where k = Cp /Cv
The higher the compression ratio, the more powerful the engine is and the higher its efficiency is.
Compression ratios have been required to decrease due to emmission laws.
Kenai Halvorson
University of Alaska Fairbanks
March 24, 2005
Physics 212x
with David Newman
http://biotsavart.tripod.com/ice.htm
Pv Diagram of the Otto cycle
On the PV-diagram 1-2 is the intake, 2-3 is compression, 3-4 is the ignition, 4-5 is the Exhaust and
5-2is the heat expulsion.