- #1
Rx7man
- 425
- 189
Homework Statement
I am working on creating a spreadsheet where you can input the parameters of an engine at a given rotational speed such as volumetric efficiency, boost pressure, atmospheric pressure and temperature, and compressor efficiency... It's been a very long time since I've done thermodynamics, and have forgotten too much of it to derive all the equations.
To start with, let's forget about engine speed, volumetric efficiency, and compressor efficiency, and assume perfect adiabatic compression.
The online calculators I found require the volumes to be known, not the pressures
Homework Equations
Working with an initial volume of 1 m3 at atmospheric conditions
P initial = 101,000 pa
T initial = 300K
V initial = 1
Calculate n from ideal gas law: PV = nRT, (n= PV/RT), n = (101000*1)/(8.314*300), n = 40.5
We know n inital = n final
Pfinal = 303,000 pa (3:1 pressure ratio)
Work = ?
T final =?
V final =?
The Attempt at a Solution
I was trying to work out the solution with the help of this site but I'm not getting too far with it
http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/adiab.html
When I get there, I will factor in the compressor efficiency as a function of extra work added to the system... So if a perfect system would require 10J, a 50% efficient system would require 20J, raising the temperature and volume, but keeping the pressure the same (since the pressure is what I measure and control)
Thanks for the help... My mind has turned to mush looking at this for a couple hours