[MAK_JUST_University]

Hi fluent's

i need you valuable help please

I'm modeling a gas ejector and i'm really stuck and toughly struggling

In fact I'm working on 2d-axisymmetry modeling for supersonic ejector using NIST real gas for R134a and i'm not getting any convergence especially for continuity and x-velocity variables.

also i'm getting REFPROP_error (203) from function: tprho (density)
[TPRHO error 203] vapor iteration has not converged

i will highly appreciate you kind assistance regarding the issue

Yours
Moh'd

[aerospace84]

hello! have you tried before going with gases using air ideal gas or easier like water if the model you've set up really work?

[MAK_JUST_University]

Thanks Luke for your kind reply

Yes i tried using ideal gas as a working fluid and first order schemes intending to use the results to initialize the true real gas NIST model

but the convergence progress is very slow where its almost indicates a constant values for the scaled residuals even after 17500 iterations

I would highly appreciate if you passed to the attachment file where i captured a snapshot for the scaled residuals history

Yours
Moh'd

[aerospace84]

Hi, attached my residuals. how many elements do you have?

[MAK_JUST_University]

This report is generated by FLUENT
Awaiting your kind comment


Mesh Quality:
Orthogonal Quality ranges from 0 to 1, where values close to 0 correspond to low quality.
Minimum Orthogonal Quality = 5.81132e-01
Maximum Aspect Ratio = 3.66096e+00

Domain Extents:
x-coordinate: min (m) = -7.430342e-02, max (m) = 1.618900e-01
y-coordinate: min (m) = 0.000000e+00, max (m) = 1.311797e-02
Volume statistics:
minimum volume (m3): 2.703190e-12
maximum volume (m3): 1.009905e-09
total volume (m3): 2.606182e-05
minimum 2d volume (m3): 1.216947e-09
maximum 2d volume (m3): 1.396445e-08
Face area statistics:
minimum face area (m2): 2.710528e-05
maximum face area (m2): 1.405167e-04
Checking mesh...........................

[aerospace84]

HI! It seem good! but i don't read the number of elements and i don't know your geometry but the quality is good. Have you tried non ideal gas?I mean air with constat density?if it doesn't work in this way probably there are some problems with the boundary conditions...I suggest pressure inlet and outlet and then compute the flow rate from the results

[ali_ranjbar]

Originally Posted by MAK_JUST_University

Hi fluent's

i need you valuable help please

I'm modeling a gas ejector and i'm really stuck and toughly struggling

In fact I'm working on 2d-axisymmetry modeling for supersonic ejector using and ia'm not getting any convergence especially for continuity and x-velocity variables.

also i'm getting REFPROP_error (203) from function: tprho (density)
[TPRHO error 203] vapor iteration has not converged

i will highly appreciate you kind assistance regarding the issue

Yours
Moh'd

please i need to know how you used NIST real gas for R134a? i really need to know what is the ufd code for the R134a real gas and my emali is ali.r1995@outlook.com , please I need force help form you sir