0
$\begingroup$

I tried to understand of some formulas in ISA Standard "Flow Equations for Sizing Control Valves": http://integrated.cc/cse/ISA_750101_SPBd.pdf

ISA standard likes to give formulas without giving reasons. For example, following formula is about expansion factor Y (page 22, Eq.32) :

$$ Y = 1- \frac{x}{3F_{\gamma}x_T} $$

I've spent a lot of time trying to figure above formula out, but without success. I would be very grateful if someone could give a derivation, or you could point me to a literature.

$\endgroup$
4
  • 1
    $\begingroup$ Dimensional analysis is one possibility see BReynolds and Buckingham. Or it may derive from experimental work. $\endgroup$
    – Solar Mike
    Apr 19, 2023 at 5:00
  • $\begingroup$ I don't think so. $\endgroup$
    – John
    Apr 19, 2023 at 5:52
  • $\begingroup$ So with valves, or what can be assumed to be orifices, how do you get the coefficient of discharge? As you "don't think so" ?? I remember "proving" those coefficients by experiment as labs at uni... $\endgroup$
    – Solar Mike
    Apr 19, 2023 at 6:50
  • $\begingroup$ Dear Mike, You may be right, I find Buckingham's old paper, maybe it has answer. Thank you! $\endgroup$
    – John
    Apr 19, 2023 at 7:08

0

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service and acknowledge you have read our privacy policy.

Browse other questions tagged or ask your own question.