Swirl equation in Heywood book
 

Hello everyone!

One of the important parameters in IC engine CFD analysis is swirl calculation. Most literature would point to the revered Internal Combustion Fundamentals book by John Heywood.

On p.345, Eq.(8.29), the equation for swirl ratio (Rs) is given. However, when I derived this equation I arrived at something similar but off by a factor of 4 (mine is 1/4 smaller than Heywood's).

I'm wondering if anyone has encountered the same problem. Could it be a typographical error in this equation? I'd really appreciate it if someone could shed some light on this.

Thank you! YKS