Hi, I'm trying to add new material to the existing fluent database. I'm following the same format as that given in the USER's guide (page 8-10). However, I get the following error. Error: GENERAL-CAR-CDR: invalid argument [1]: improper list Error object : air, I get this error even if I copy the exact format given on this page. Can you please help me out? Thanks, Ashish

I've got the same problem: Error: CAR: invalid argument [1]: wrong type [not a pair] Error Object: #f

I'll surely post the solution if and when I get it.

[cheesey]

i have this error too. may i know what does it mean? thanks.

[bgu]

One would expect that after 20 30(?) years Fluent or Ansys will provide a tool for editing the database. I tried it several times and usually failed. I do not bother with the database anymore, instead, I edit an existing material in Fluent-Materials panel and Change/Create it.

[mystic_cfd]

Hi there

We regularly make use of custom material files. Remember that it is a file written in the Scheme language and requires attention to formatting.

From your error it would appear that the Scheme interpreter has a problem with one of your lists. This can be due to unmatched parentheses, but often occurs when the text editor you use inserts additional control characters into the file (or by copying a file from Windows to run on Linux).

If you still have problems, post your file and someone will probably fix it for you...

regards

[cheesey]

(fluid
(chemical-formula . formula)
(density (constant . 1025))
(viscosity (constant . 1068.36))
temperature (constant . 293)))

above is my input..but came out this:

Error: GENERAL-CAR-CDR: invalid argument [1]: improper list
Error Object: fluid

is my database correct?

thanks!

[TDi]

I was having the same problem and found the solution in an older thread on this forum: you need another set of enclosing parentheses () around the whole thing. Thus, there are sets of parentheses for each of the whole file, each material, each property, and if needed, each numeric value.
The sample should correctly read as follows:

(
(air
  fluid
  (chemical-formula . #f)
  (density (constant . 1.225)
  (premixed-combustion 1.225 300))
  (specific-heat (constant . 1006.43))
  (thermal-conductivity (constant . 0.0242))
  (viscosity (constant . 1.7894e-05)
  (sutherland 1.7894e-05 273.11 110.56)
  (power-law 1.7894e-05 273.11 0.666))
  (molecular-weight (constant . 28.966))
  )

 (aluminum
  solid
  (chemical-formula . al)
  (density (constant . 2719))
  (specific-heat (constant . 871))
  (thermal-conductivity (constant . 202.4))
  (formation-entropy (constant . 164448.08))
  )
)

[Jui C]

I had similar problem with interpreted udf -
Error: CAR: invalid argument [1]: wrong type [not a pair] Error Object []

I was using a long name for udf with 3 underscores earlier, then changed it to a smaller one and it worked.

[wwa]

Hello,
I have the same problem and none of the solutions above work for me. I enclosed it in additional parentheses, converted it to unix format, but still encountered the same error

Error: GENERAL-CAR-CDR: invalid argument [1]: improper list
Error Object: sodium-carbonate

Can anyone have a look at that? I'm using Fluent 6.3 on Windows.

here is the code (don't mind the incorrect constants, it's just a test):

 
 ( 
  (sodium-carbonate
  fluid
  (chemical-formula . Na2CO3<s>)
  (density (constant . 2000))
  (specific-heat (constant . 1220)(polynomial piecewise-polynomial (273 1000 -464.17822 4.9711663 -0.0038992118 1.4829381e-06 -2.8855555e-10) (1000 5000 1031.5207 1.150554 -0.00046290062 8.9357071e-08 -6.372102e-12)))
  (molecular-weight (constant . 104))
  (formation-enthalpy (constant . -101.268))
  (reference-temperature (constant . 298))
  (formation-entropy (constant .  0.5731747e+04))
  (species-phase (constant . 1))
  )
  
  (sodium-sulfite
  fluid
  (chemical-formula . Na2SO3<s>)
  (density (constant . 2000))
  (specific-heat (constant . 1220)(polynomial piecewise-polynomial (273 1000 -464.17822 4.9711663 -0.0038992118 1.4829381e-06 -2.8855555e-10) (1000 5000 1031.5207 1.150554 -0.00046290062 8.9357071e-08 -6.372102e-12)))
  (molecular-weight (constant . 124))
  (formation-enthalpy (constant . -101.268))
  (reference-temperature (constant . 298))
  (formation-entropy (constant .  0.5731747e+04))
  (species-phase (constant . 1))
  )
 )

Thanks for replies,

Peter

[robboflea]

Hi all,

I came across this problem when trying to define a new material using the data insertion mask from fluent gui.
I solved it by specifying the database name and the materials names in lower-case letters.

Hope this helps!

Rob

[nasser]

hi friend
its the best way :
The materials database is located in the following file:

path /Fluent.Inc/fluent6. /cortex/lib/propdb.scm
where path is the directory in which you have installed FLUENT and the variable corresponds to your release version, e.g., 1 for fluent6.1.

If you wish to enhance the materials database to include additional materials that you use frequently, you can follow the procedure below:

1.
Copy the file propdb.scm from the directory listed above to your working directory.
2.
Using a text editor, add the desired material(s) following the format for the other materials. You may want to copy an existing material that is similar to the one you want to add, and then change its name and properties. The entries for air and aluminum are shown below as examples:
(air
fluid
(chemical-formula . #f)
(density (constant . 1.225)
(premixed-combustion 1.225 300))
(specific-heat (constant . 1006.43))
(thermal-conductivity (constant . 0.0242))
(viscosity (constant . 1.7894e-05)
(sutherland 1.7894e-05 273.11 110.56)
(power-law 1.7894e-05 273.11 0.666))
(molecular-weight (constant . 28.966))
)

(aluminum
(solid)
(chemical-formula . al)
(density (constant . 2719))
(specific-heat (constant . 871))
(thermal-conductivity (constant . 202.4))
(formation-entropy (constant . 164448.08))
)
When you next load the materials database in a FLUENT session started in the working directory, FLUENT will load your modified propdb.scm, rather than the original database, and your custom materials will be available in the Database Materials panel.

If you want to make the modified database available to others at your site, you can put your customized propdb.scm file in the cortex/lib directory, replacing the default database. Before doing so, you should save the original propdb.scm file provided by Fluent Inc. to a different name (e.g., propdb.scm.orig) in case you need it at a later time.

[Per_Holmgren]

Old topic I know but how much I might try I always end up here.

I have a problem related to this, where I simply want to add one more product (ko2) released from the combustion of wood. Copying the materials I want to modify and moving them to my own database doesn't really help.

For instance, I have this in the default database:

(wood-volatiles-air mixture
(chemical-formula . #f)
(species (names wood_vol o2 co2 h2o n2))
(reactions (finite-rate ("reaction-1" ((wood_vol 1 0.2 1) (o2 1.058 1.3 1)) ((co2 1 0 1) (h2o 1.191 0 1)) ((n2 0 1)) (stoichiometry "1wood_vol + 1.058o2 --> 1co2 + 1.191h2o") (arrhenius 211900000000. 202700000. 0) (mixing-rate 4 0.5) (specified-rate-exponents? . #t) (use-third-body-efficiencies? . #f))) (finite-rate/eddy-dissipation ("reaction-1" ((wood_vol 1 0.2 1) (o2 1.058 1.3 1)) ((co2 1 0 1) (h2o 1.191 0 1)) ((n2 0 1)) (stoichiometry "1wood_vol + 1.058o2 --> 1co2 + 1.191h2o") (arrhenius 211900000000. 202700000. 0) (mixing-rate 4 0.5) (specified-rate-exponents? . #t) (use-third-body-efficiencies? . #f))) (eddy-dissipation ("reaction-1" ((wood_vol 1 1 0) (o2 1.058 1 1)) ((co2 1 0 1) (h2o 1.191 0 1)) ((n2 0 1)) (stoichiometry "1wood_vol + 1.058o2 --> 1co2 + 1.191h2o") (arrhenius 211900000000. 202700000. 0) (mixing-rate 4 0.5) (specified-rate-exponents? . #t) (use-third-body-efficiencies? . #f))))
)


So, for ease of view, I will just use the finite rate parameters (the first part of the code). If I change them to:

(chemical-formula . #f)
(species (names wood_vol o2 co2 h2o ko2 n2))
(reactions (finite-rate ("reaction-1" ((wood_vol 1 0.2 1) (o2 1.059 1.3 1)) ((co2 1 0 1) (h2o 1.191 0 1) (ko2 0.001 0 1)) ((n2 0 1)) (stoichiometry "1wood_vol + 1.059o2 --> 1co2 + 1.191h2o + 0.001ko2") (arrhenius 211900000000. 202700000. 0) (mixing-rate 4 0.5) (specified-rate-exponents? . #t) (use-third-body-efficiencies? . #f)))

I get the error

Error: GENERAL-CAR-CDR: invalid argument [1]: improper list
Error Object: #f

I assume #f stands for function? If so, how do I access that?

I can't really modify the material like I want to using Fluents functions, since even if I try to edit the property Mixture Species, I can't do anything other than look at the species already present. There is no way of actually adding species

I can open it up in Fluent and change Stochiometric Coefficinets and Rate Exponents, but I can't use my new material because of the warnings.

So, should I go back to the textbook, or is there someone here who could show me some mercy?