Changing steam.dat to ammonia data

[09513]

I am currently working on a CFD-analysis of some pipes, where I need to use a subsonic solver, which means that I need variable density, which means I need to modify my steam.dat-file to have ammonia-data instead of the default water-steam.

I have more or less figured out how to do it, import to excel from dat-file, change data to ammonia and then export again, (I haven´t exported yet).

But I want to know, that what I am doing is correct.

- which temperature-steps would be sufficient.

- how many values are needed.

- some of the values are divided by numbers like "0.2 25" and "0.4 23", what are their function?

[marco.mueller]

Hello,

- which temperature-steps would be sufficient.

- how many values are needed.

Both questions seem to be similar?! It depends on how good your results have to be, similar to the mesh resultion or other material properties. As a starting point you can chose maybe a rough assumption with only a few values.

- some of the values are divided by numbers like "0.2 25" and "0.4 23", what are their function?

this line (and the others) defines a single isobar for the steam properties. In your example it is the 0.2 psi isobar and 25 temperature values (in the lines beneath) specify the curve.