# Homework Help: [Thermodynamics] Quick question about ''Cut-off ratio'' in the Diesel Cycle.

1. Jun 19, 2010

### Je m'appelle

[SOLVED] Quick question about ''Cut-off ratio'' in the Diesel Cycle.

So I've been studying the Diesel Cycle, and I've come up with something called the ''cut-off ratio'', which is simply a name for the ratio of expansion $$r_E$$.

But I'm getting different definitions for this ratio.

For example, in the below link the expansion ratio is given by $$r_E = \frac{V_1}{V_3}$$

http://hyperphysics.phy-astr.gsu.edu/hbase/thermo/diesel.html#c2

And in this other link the expansion ratio is given differently by $$r_E = \frac{V_3}{V_2}$$

http://www.taftan.com/thermodynamics/DIESEL.HTM

I'm confused, can someone enlighten me please, are those expressions similar, if yes, how so?

Thanks.

Last edited: Jun 20, 2010
2. Jun 20, 2010

### Je m'appelle

I've already found out what I was getting wrong.

Thanks for all the help I was provided.

3. Jun 29, 2010