Talk:Discharge coefficient

Expands?
I don't know what this part is supposed to mean: "which expands an identical working fluid from the same initial conditions to the same exit pressure." Expands? Identical? Identical to what? The same initial conditions as what? The same exit pressure as what? Are these words supposed to describe what an ideal nozzle does to any working fluid, i.e. behave reliably? Nicknicknickandnick (talk) 08:50, 25 December 2010 (UTC)

answer by Peng, Sen: first of all, you need to know how Cd works. don't haning around with "definitions".

this coefficient is going to be used under below circumstance: when you calculating a orifice discharging problem, the only thing you know is orifice diameter and upstream conditions like pressure and temperature. while you can not calculate mass flow rate with orifice area and velocity/pressure/temperature at orifice because you do not know these condition at orifice itself. instead, you assume there is a ideal condition took place downstream of this orifice, where you can calculate the ideal pressure/temprature/density of working fluid there base on known condition of orifice upstream. so you use these downstream ideal condition combine with real orifice area to calculate mass flow rate. obviously, you can not get a right answer because these parameters came from differerent station, beside, they came from ideal isentropic deduction. to correct this calculation, you use Cd to correct this formular. of course, you have to know Cd prior to your calculation, actually Cd came from experiment before you start your calculation. you actually use Cd/orifice area/upstream condition to calculate actual mass flow accross the orifice. — Preceding unsigned comment added by 202.50.49.9 (talk) 08:22, 31 October 2011 (UTC)

The post is fine for most to all of Nick's comments. When the words "identical" or "same" are used, they refer to conditions that are congruent in both a non-ideal case and an ideal case. Onionmon (talk) 22:30, 5 June 2012 (UTC)

Flow coefficient vs discharge coefficient
What's the difference?--86.12.160.194 (talk) 16:46, 8 April 2019 (UTC)

Article is garbage
This article is complete garbage - the definitions are completely wrong - I have attempted to remedy iyt by replaving "theoretical" with "ideal" but it is still very bad - needs someone with better Wikipedia skills than I to sort it out — Preceding unsigned comment added by 195.89.73.55 (talk) 08:51, 6 October 2021 (UTC)