/[ascend]/trunk/models/johnpye/fprops/ammonia.c
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revision 1859 by jpye, Sun Sep 14 07:22:39 2008 UTC revision 1860 by jpye, Sun Sep 14 08:00:29 2008 UTC
# Line 5  Ideal gas data for Ammonia, from Tillner Line 5  Ideal gas data for Ammonia, from Tillner
5  Baehr, 'Eine neue Fundamentalgleichung für Ammoniak', DKV-Tagungsbericht,  Baehr, 'Eine neue Fundamentalgleichung für Ammoniak', DKV-Tagungsbericht,
6  20:167-181, 1993. This is the ammmonia property correlation recommended  20:167-181, 1993. This is the ammmonia property correlation recommended
7  by NIST in its program REFPROP 7.0.  by NIST in its program REFPROP 7.0.
   
 WARNING NOTE:  
 These parameters are currently created by a curve fit to the REFPROP output  
 using Fityk. FIXME use the published parameters for these values, and work  
 out why they weren't correct earlier (for some reason, 'correct' values gave  
 a cons  
   
   
   
   
 istent 0.01% error relative to REFPROP output).  
8  */  */
9  const IdealData ideal_data_ammonia = {  const IdealData ideal_data_ammonia = {
10      -15.815020 /* const */      -15.815020 /* const */
# Line 24  const IdealData ideal_data_ammonia = { Line 13  const IdealData ideal_data_ammonia = {
13      , 488.189 /* cpstar J/kgK */      , 488.189 /* cpstar J/kgK */
14      , 3 /* power terms */        , 3 /* power terms */  
15      , (const IdealPowTerm[]){      , (const IdealPowTerm[]){
16    #if 0
17            {1.8871646035249E+01, -1./3}
18            ,{5.9549943513550E-04, 3./2}
19            ,{-7.4983130863099E-05, 7./4}
20    #else
21    /*
22    WARNING NOTE:
23    These parameters are currently created by a curve fit to the REFPROP output
24    using Fityk. FIXME use the published parameters for these values, and work
25    out why they weren't correct earlier (for some reason, 'correct' values gave
26    a consistent 0.01% error relative to REFPROP output).
27    
28    The following parameters are ALL larger than the 'official' values above by a
29    factor of about 1.000056. It would appear that REFPROP is using a different
30    value of cpstar in its calculations (The value 488.189 is clearly stated by
31    Tillner-Roth, but perhaps REFPROP chooses to use the molecular mass instead
32    of this value, or do some other kind of scaling...)
33    */
34          {9213.45/488.189, -1./3.}          {9213.45/488.189, -1./3.}
35          ,{0.290733/488.189, 3./2.}          ,{0.290733/488.189, 3./2.}
36          ,{-0.036608/488.189, 7./4.}          ,{-0.036608/488.189, 7./4.}
37    #endif
38      }      }
39      , 0, (const IdealExpTerm *)0 /* no exponential terms */      , 0, (const IdealExpTerm *)0 /* no exponential terms */
40  };  };

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john.pye@anu.edu.au
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