The operating pressure is stored in both case and data files

Let's setup a problem ("case1.cas", "case1.dat") with a certain operating pressure Pop1.
Modify "case1.cas" by changing thse operating pressure to Pop2 and any other variables then save under "case2.cas".
If you read in "case1.dat" in "" the operating pressure displayed in the Operating Conditions panel will not be Pop2 but Pop1.

The reason behind this change is because the operating pressure is also stored in data files.
So although the operating pressure was changed to Pop2 in "case2.cas", the fact that the user read "case2.dat" changed the value in the operating panel back to Pop1. The value of the operating pressure in the case file was overwritten by the value in the data file.

The need to store the operating pressure in the data file is related to the "floating operating pressure'' option in FLUENT. In fact, FLUENTprovides the floating operating pressure option to handle time-dependent compressible flows with a gradual increase in the absolute pressure in the domain. In these cases, it is necessary to have the value of the operating pressure stored in the data file so that further runs can be completed with the right operating pressure. However, FLUENT doesn't make a distinction between cases with floating operating pressure and constant operating pressure and hence the operating pressure is always stored in the data file.

If you edit a data file, you'll see the operating pressure value displayed (see below).

(0 "fluent6.1.18")

(0 "Machine Config:")
(4 (60 0 0 1 2 4 4 4 8 4 4))

(0 "Grid size:")
(33 (1230 1993 764))

(0 "Variables:")
(37 (
(flow-time 0)
(time-step 0)
(periodic/pressure-derivative 0)
(number-of-samples 0)
(dpm/summary ())
(operating-pressure 101725)
(delta-time-sampled 0)))

(0 "Data:")

(0 "SV_P, domain 1, cell zone 9, 1230 cells:")
(2300 (1 9 1 0 1 1 1230)

Show Form
No comments yet. Be the first to add a comment!