2 replies to this topic

[Sara Owens]

Has anyone done the direct intergration of the isentropic nozzle flow per API 520 part 1. I'm looking at Ninth edition. There is a table C2, pg 115, . which shows the example for the results of the direct intergration. i'm trying to calculate the method and i'm running thru errors. i can't get my numbers to match with the table.

I'm trying to find Mass flux, and i'm using their equation fround in line C.4 Pg 112.

 

I cannot find out how to get density_t. The density_t is what i need to find mass flux, but i plugged the densities from the table and i can't seem to find a match.

 

anyone tried this before?

[breizh]

Hi Sara,

You may find some interest reading the documents attached .

hope this is helping you and others.

Breizh

[PaoloPemi]

Sara,

I have not access to Ninth edition however for single phase applications the method is simple and you should't have problems,

by evaluating the properties at different conditions results are more accurate than old API formulation (based on integration with constant cp/cv), this is true in most cases near or above PC,

in addition to the documents provided by breizh, you may also find useful the alternative formulations included in psvcompare1.xls see post 21 of thread

https://www.cheresou...ing-temperature

if, instead, you have phase changes, things are much more complex and there is not a general consensus vs HEM or HNE or HNE-DS etc. to mention a few...

Edited by PaoloPemi, 20 March 2019 - 05:51 AM.