R123 !Short name 306-83-2 !CAS number 2,2-Dichloro-1,1,1-trifluoroethane !Full name CHCl2CF3 !Chemical formula {C2HCl2F3} HCFC-123 !Synonym 152.931 !Molar mass [g/mol] 166.0 !Triple point temperature [K] 300.973 !Normal boiling point [K] 456.831 !Critical temperature [K] 3661.8 !Critical pressure [kPa] 3.596417 !Critical density [mol/L] 0.28192 !Acentric factor 1.356 !Dipole moment [Debye]; Meyer & Morrison (1991) J. Chem. Eng. Data 36:409-413. IIR !Default reference state 10.0 !Version number ???? !UN Number :UN: halocb !Family :Family: ???? !Heating value (upper) [kJ/mol] :Heat: 77. !GWP (IPCC 2007) :GWP: 0.01 !ODP (WMO 2010) :ODP: 9100. !RCL (ppm v/v, ASHRAE Standard 34, 2010) :RCL: B1 !Safety Group (ASHRAE Standard 34, 2010) :Safety: 1S/C2HCl2F3/c3-1(4)2(5,6)7/h1H !Standard InChI String :InChi: OHMHBGPWCHTMQE-UHFFFAOYSA-N !Standard InChI Key :InChiKey: ???? !Alternative fluid for mixing rules :AltID: efdfede0 !Hash number from InChI Key :Hash: !The fluid files contain general information about the fluid in the first 15 to 20 lines, followed by sections for the ! equations of state, transport equations, and auxiliary equations. Equations of state are listed first. The NIST recommended ! equations begin with a hash mark (#). The secondary equations begin with the @ symbol. These symbols can be swapped to ! select a secondary equation as primary and the primary as secondary. The equation of state section also contains auxiliary ! equations for the ideal gas heat capacity or ideal gas Helmholtz energy. Below the equations of state (both primary and ! secondary) are the transport equations, first viscosity and then thermal conductivity. These are then followed by the ! secondary equations if available. The transport section also contains auxiliary equations required to calculate either the ! dilute gas state or the critical enhancement. At the end of the file are additional but not necessary auxiliary equations, ! including simple equations for the vapor pressure, saturated liquid and vapor densities, melting line (for some fluids), and ! sublimation line (for even fewer fluids). This section also contains the equations for dielectric constant and surface ! tension if available. The sections are divided by different symbols (these being _-+=^*~) to aid the eye in locating a ! particular section. Secondary equations are indented 10 spaces to avoid confusion with the NIST recommended equations. The ! end of the fluid file is marked with @END. Anything below that is ignored. ! compiled by M. McLinden, NIST Physical and Chemical Properties Division, Boulder, Colorado ! 10-10-95 MM, Original version. ! 11-01-99 EWL, Add Span 12 term short equation of state. ! 08-17-10 IDC, Add ancillary equations. ! 12-06-12 EWL, Add surface tension coefficients of Mulero et al. (2012). ! 04-25-18 MLH, Add TK3 block to replace TK1 block. ________________________________________________________________________________ #EOS !---Equation of state--- BWR !MBWR equation of state for R-123 of Younglove and McLinden (1994). :TRUECRITICALPOINT: 456.831 3.596417 !True EOS critical point [K, mol/L] (where dP/dD=0 and d^2P/dD^2=0 at constant T) :DOI: 10.1063/1.555950 ? ?``````````````````````````````````````````````````````````````````````````````` ?Younglove, B.A. and McLinden, M.O., ? "An International Standard Equation of State for the Thermodynamic ? Properties of Refrigerant 123 (2,2-Dichloro-1,1,1-Trifluoroethane)," ? J. Phys. Chem. Ref. Data, 23:731-779, 1994. ? ?The uncertainties of the equation of state are 0.1% in density, 1.5% in heat ? capacity, and 2% in the speed of sound, except in the critical region. ? The uncertainty in vapor pressure is 0.1%. Uncertainties are greater below ? 180 K. ? !``````````````````````````````````````````````````````````````````````````````` 166.0 !Lower temperature limit [K] 600.0 !Upper temperature limit [K] 40000.0 !Upper pressure limit [kPa] 11.60 !Maximum density [mol/L] CPP !Pointer to Cp0 model 152.931 !Molar mass [g/mol] 166.0 !Triple point temperature [K] 0.004202 !Pressure at triple point [kPa] 11.58 !Density at triple point [mol/L] 300.973 !Normal boiling point temperature [K] 0.28192 !Acentric factor 456.831 3661.8 3.596417 !Tc [K], pc [kPa], rhoc [mol/L] 456.831 3.596417 !Reducing parameters [K, mol/L] 3.596417 !gamma 0.08314510 !Gas constant [L-bar/mol-K] 32 1 !Nterm, Ncoeff per term -0.00657453133659 2.93479845842 -98.9140469845 20102.9776013 -3835665.27886 0.00227587641969 -9.0872681945 4341.81417995 3541164.64954 -0.00063539484967 3.20786715274 -1312.76484299 -0.116360713718 -11.3354409016 -5375.43457327 2.5811241612 -0.106148632128 50.0026133667 -2.04326706346 -2494383.45685 -463962781.113 -284903.429588 0.974392239902e+10 -6373.14379308 314121.189813 -145.747968225 -8438302.61449 -2.41138441593 1085.08031257 -0.0106653193965 -12.1343571084 -257.51038324 #AUX !---Auxiliary function for Cp0 CPP !Ideal gas heat capacity function for R-123 of Younglove & McLinden (1994). ? ?``````````````````````````````````````````````````````````````````````````````` ?Younglove, B.A. and McLinden, M.O., 1994. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 1.0 1.0 !Reducing parameters for T, Cp0 4 0 0 0 0 0 0 !Nterms: polynomial, exponential, cosh, sinh 17.01154 0.0 0.4046308 1.0 -0.0004644803 2.0 2.347418e-7 3.0 #AUX !---Auxiliary function for PX0 PX0 !Helmholtz energy ideal-gas function for R-123 of Younglove & McLinden (1994). ? ?``````````````````````````````````````````````````````````````````````````````` ?Younglove, B.A. and McLinden, M.O., 1994. ? !``````````````````````````````````````````````````````````````````````````````` 1 5 0 0 0 0 0 0 !Nterms: ai*log(tau**ti); ai*tau**ti; ai*log(1-exp(bi*tau)) 1.0460186721932314 1.0 !ai, ti for [ai*log(tau**ti)] terms -13.2327874222552726 0.0 !aj, ti for [ai*tau**ti] terms 10.948194603389112 1.0 !aj, ti for [ai*tau**ti] terms 0.0486659157339362 -1.0 -0.558641584869e-04 -2.0 0.282329586824e-07 -3.0 -------------------------------------------------------------------------------- @EOS !---Equation of state--- FE1 !Helmholtz transformation of MBWR EOS for R-123 of Younglove & McLinden (1994). ? ?``````````````````````````````````````````````````````````````````````````````` ?Younglove, B.A. and McLinden, M.O., ? "An International Standard Equation of State for the Thermodynamic ? Properties of Refrigerant 123 (2,2-Dichloro-1,1,1-trifluoroethane)," ? J. Phys. Chem. Ref. Data, 23:731-779, 1994. ? ?The equation here is the same as the Younglove and McLinden BWR equation, ? but has been transformed into the fundamental Helmholtz energy form. ? !``````````````````````````````````````````````````````````````````````````````` 166.0 !Lower temperature limit [K] 600.0 !Upper temperature limit [K] 40000.0 !Upper pressure limit [kPa] 11.60 !Maximum density [mol/L] CPP !Pointer to Cp0 model 152.931 !Molar mass [g/mol] 166.0 !Triple point temperature [K] 0.0042 !Pressure at triple point [kPa] 11.60 !Density at triple point [mol/L] 300.973 !Normal boiling point temperature [K] 0.28192 !Acentric factor 456.831 3661.8 3.596417 !Tc [K], pc [kPa], rhoc [mol/L] 456.831 3.596417 !Reducing parameters [K, mol/L] 8.314510 !Gas constant [J/mol-K] 40 4 0 0 0 0 0 0 0 0 0 0 !# terms and # coefs/term for normal terms, Gaussian terms, and Gao terms -10.0242647494 3.0 0. 0. !a(i),t(i),d(i),l(i) -0.280607656419 4.0 0. 0. 0.0206814471606 5.0 0. 0. -0.284379431451 0.0 1. 0. 5.93928110321 0.5 1. 0. -9.36560389528 1.0 1. 0. 4.16660793675 2.0 1. 0. -1.74023292951 3.0 1. 0. 0.177019905365 0.0 2. 0. -1.5472169226 1.0 2. 0. 1.6182049559 2.0 2. 0. 2.88903529383 3.0 2. 0. -0.118493874757 0.0 3. 0. 1.30952266209 1.0 3. 0. -1.17308103711 2.0 3. 0. -0.12812513195 1.0 4. 0. -0.0786087387513 2.0 5. 0. -0.0816000499305 3.0 5. 0. 0.0536451054311 2.0 6. 0. -0.00680078211929 2.0 7. 0. 0.00701264082191 3.0 7. 0. -0.000901762397311 3.0 8. 0. 10.0242647494 3.0 0. 2. 0.280607656419 4.0 0. 2. -0.0206814471606 5.0 0. 2. 7.98923878145 3.0 2. 2. -0.547972072476 4.0 2. 2. -0.0206814470584 5.0 2. 2. 2.49142724365 3.0 4. 2. -0.273986034884 4.0 4. 2. 0.236001863614 5.0 4. 2. 0.540528251211 3.0 6. 2. -0.0600457561959 4.0 6. 2. 0.0786672874826 5.0 6. 2. 0.0708085874508 3.0 8. 2. -0.0150114389748 4.0 8. 2. 0.00182205199477 5.0 8. 2. 0.00314978575163 3.0 10. 2. 0.00784455573794 4.0 10. 2. 0.000364410397155 5.0 10. 2. @EOS !---Equation of state--- FES !Helmholtz equation of state for R-123 of Span and Wagner (2003). ? ?``````````````````````````````````````````````````````````````````````````````` ?Span, R. and Wagner, W. ? "Equations of State for Technical Applications. III. Results for Polar Fluids," ? Int. J. Thermophys., 24(1):111-162, 2003. doi: 10.1023/A:1022362231796 ? ?The uncertainties of the equation of state are approximately 0.2% (to ? 0.5% at high pressures) in density, 1% (in the vapor phase) to 2% in ? heat capacity, 1% (in the vapor phase) to 2% in the speed of sound, and ? 0.2% in vapor pressure, except in the critical region. ? !``````````````````````````````````````````````````````````````````````````````` 166.0 !Lower temperature limit [K] 600.0 !Upper temperature limit [K] 100000.0 !Upper pressure limit [kPa] 11.62 !Maximum density [mol/L] CPP !Pointer to Cp0 model 152.931 !Molar mass [g/mol] 166.0 !Triple point temperature [K] 0.0041534 !Pressure at triple point [kPa] 11.613 !Density at triple point [mol/L] 300.96 !Normal boiling point temperature [K] 0.283 !Acentric factor 456.82 3672.0 3.6160098 !Tc [K], pc [kPa], rhoc [mol/L] 456.82 3.6160098 !Reducing parameters [K, mol/L] 8.31451 !Gas constant [J/mol-K] 12 4 0 0 0 0 0 0 0 0 0 0 !# terms and # coefs/term for normal terms, Gaussian terms, and Gao terms 1.116973 0.25 1. 0. !a(i),t(i),d(i),l(i) -3.074593 1.25 1. 0. 0.51063873 1.5 1. 0. 0.094478812 0.25 3. 0. 0.00029532752 0.875 7. 0. 0.66974438 2.375 1. 1. 0.96438575 2.0 2. 1. -0.014865424 2.125 5. 1. -0.49221959 3.5 1. 2. -0.022831038 6.5 1. 2. -0.1407486 4.75 4. 2. -0.025117301 12.5 2. 3. ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ #ETA !---Viscosity--- VS1 !Pure fluid viscosity model for R-123 of Tanaka and Sotani (1995). :DOI: 10.1007/BF01443394 ? ?``````````````````````````````````````````````````````````````````````````````` ?Tanaka, Y. and Sotani, T., ? "Transport Properties (Thermal Conductivity and Viscosity)," ? in McLinden, M.O., editor. R123--Thermodynamic and Physical ? Properties. Paris, International Institute of Refrigeration, 1995. ? ?see also: Int. J. Thermophys., 17(2):293-328, 1996. doi: 10.1007/BF01443394 ? ?The uncertainty in viscosity is 5%. ? !``````````````````````````````````````````````````````````````````````````````` 166.0 !Lower temperature limit [K] 600.0 !Upper temperature limit [K] 40000.0 !Upper pressure limit [kPa] 15.90 !Maximum density [mol/L] 4 !Number of terms associated with dilute-gas function NUL !Pointer to collision integral model 0.5909 !Lennard-Jones coefficient sigma [nm] 275.16 !Lennard-Jones coefficient epsilon/kappa [K] 1.0 1.0 !Reducing parameters for T, eta 0.0 0.5 !Chapman-Enskog term (not used here) -2.273638 0.0 !Polynomial term: Coefficient, power of T 0.05099859 1.0 -2.402786e-5 2.0 0 !# initial density terms (these are merged with residual term) 1 6 1 2 0 0 !# resid terms: close-packed density; simple poly; numerator of rational poly; denominator of rat. poly; numerator of exponential; denominator of exponential 1.0 0.006538897 1.0 !Reducing parameters for T, rho (= 1/MW), eta 1828.263 0.0 0. 0. 0 ! rho_0; powers of tau, del, del0; power of del in exponential [0 indicated no exponential term present] -176.2849 0.0 0. 0. 0 ! d0/rho_0 -0.02226484 0.0 1. 0. 0 ! const term in Eqn 2.8 (the initial density term) 5.550623e-5 1.0 1. 0. 0 !Temperature term in Eqn 2.8 -0.1009812 0.0 1. 0. 0 ! d1 in Eqn 2.9 6.161902e-5 0.0 2. 0. 0 ! d2 -8.84048e-8 0.0 3. 0. 0 ! d3 -322295.1 0.0 0. 0. 0 ! d0 in numerator of rational polynomial 1.0 0.0 1. 0. 0 ! rho in denominator of rational polynomial -1.0 0.0 0. 1. 0 ! rho_0 in denominator of rational polynomial NUL !Pointer to the viscosity critical enhancement auxiliary function (none used) ================================================================================ #TCX !---Thermal conductivity--- TC1 !Pure fluid thermal conductivity model for R-123 of Laesecke et al. (1996). :DOI: 10.1016/0140-7007(96)00019-9 ? ?``````````````````````````````````````````````````````````````````````````````` ?Laesecke, A., Perkins, R.A., and Howley, J.B., ? "An Improved Correlation for the Thermal Conductivity of HCFC123 ? (2,2-Dichloro-1,1,1-Trifluoroethane)," ? Int. J. Refrig., 19:231-238, 1996. doi: 10.1016/0140-7007(96)00019-9 ? ?The uncertainty in thermal conductivity is 2%, according to Laesecke et al, 1996. However, data published after 1996 (Perkins, R., Cusco, L., Howley, J., Laesecke, A., Matthes, S., Ramires, M.L.V., "Thermal Conductivities of Alternatives to CFC-11 for Foam Insulation," J. Chem. Eng. Data, 46:428-432, 2001. doi: 10.1021/je990337k) ? suggest that the uncertainty in gas phase thermal conductivity may be 10-20%. ? !``````````````````````````````````````````````````````````````````````````````` 166.0 !Lower temperature limit [K] 600.0 !Upper temperature limit [K] 67000.0 !Upper pressure limit [kPa] 12.42 !Maximum density [mol/L] (= 1900 kg/m^3) 2 0 !# terms for dilute gas function: numerator, denominator 1.0 1.0 !Reducing parameters for T, tcx -0.00778 0. !Coefficient, power in T 5.695e-5 1. 12 0 !# terms for background gas function: numerator, denominator 456.831 3.596417 1. !Reducing parameters for T (= Tc), rho (= Dc), tcx 0.0642894 -1.5 1. 0. !Coefficient, powers of Tau=T/Tc (= -powers of Tc/T), del, spare for future use -0.0530474 -2. 1. 0. 0.453522e-4 -6. 1. 0. -0.139928 0. 2. 0. 0.16654 -0.5 2. 0. -0.0162656 -1.5 2. 0. 0.136819 0. 3. 0. -0.183291 -0.5 3. 0. 0.0357146 -1.5 3. 0. -0.023121 0. 4. 0. 0.0341945 -0.5 4. 0. -0.00757341 -1.5 4. 0. TK3 !Pointer to critical enhancement auxiliary function #AUX !---Auxiliary function for the thermal conductivity critical enhancement TK3 !Simplified thermal conductivity critical enhancement for R123 of Perkins et al. (2013). ? ?``````````````````````````````````````````````````````````````````````````````` ?Perkins, R.A., Sengers, J.V., Abdulagatov, I.M., and Huber, M.L., ? "Simplified Model for the Critical Thermal-Conductivity Enhancement in Molecular Fluids," ? Int. J. Thermophys., 34(2):191-212, 2013. doi: 10.1007/s10765-013-1409-z ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 9 0 0 0 !# terms: CO2-terms, spare, spare, spare 1.0 1.0 1.0 !Reducing parameters for T, rho, tcx [mW/(m-K)] 0.63 !Nu (universal exponent) 1.239 !Gamma (universal exponent) 1.02 !R0 (universal amplitude) 0.063 !Z (universal exponent--not used for t.c., only viscosity) 1.0 !C (constant in viscosity eqn = 1/[2 - (alpha + gamma)/(2*nu)], but often set to 1) 0.216e-9 !Xi0 (amplitude) [m] 0.058 !Gam0 (amplitude) [-] 0.643e-9 !Qd_inverse (modified effective cutoff parameter) [m] 685.25 !Tref (reference temperature)=1.5*Tc [K] ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ @TRN !---ECS Transport--- ECS !Extended Corresponding States model (R134a reference); predictive mode for R-123. ? ?``````````````````````````````````````````````````````````````````````````````` ?Klein, S.A., McLinden, M.O., and Laesecke, A., "An Improved Extended Corresponding States Method for Estimation of Viscosity of Pure Refrigerants and Mixtures," Int. J. Refrigeration, 20(3):208-217, 1997. doi: 10.1016/S0140-7007(96)00073-4. ?McLinden, M.O., Klein, S.A., and Perkins, R.A., "An Extended Corresponding States Model for the Thermal Conductivity of Refrigerants and Refrigerant Mixtures," Int. J. Refrigeration, 23(1):43-63, 2000. doi: 10.1016/S0140-7007(99)00024-9 ? ?Thermal conductivity data used in the development of the extended corresponding ? states method were taken from: ? Assael, M. J. and Karagiannidis, E., "Measurements of the Thermal Conductivity of R22, R123, and R134a in the Temperature Range 250-340 K at Pressures up to 30 MPa," J Int. J. Thermophysics, V 14, N 2. P 183-197, 1993. ? ?The Lennard-Jones parameters were taken from Nabizadeh, H. and Mayinger, F., "Viscosity of gaseous R123, R134a and R142b," High Temperatures - High Pressures, 24:221, 1992. ? !``````````````````````````````````````````````````````````````````````````````` 166.0 !Lower temperature limit [K] 600.0 !Upper temperature limit [K] 40000.0 !Upper pressure limit [kPa] 11.60 !Maximum density [mol/L] FEQ R134A.FLD VS1 !Model for reference fluid viscosity TC1 !Model for reference fluid thermal conductivity NUL !Large molecule identifier 1 !Lennard-Jones flag (0 or 1) (0 => use estimates) 0.5909 !Lennard-Jones coefficient sigma [nm] for ECS method 275.16 !Lennard-Jones coefficient epsilon/kappa [K] for ECS method 1 0 0 !Number of terms in f_int term in Eucken correlation, spare1, spare2 0.00132 0. 0. 0. !Coefficient, power of T, spare1, spare2 1 0 0 !Number of terms in psi (visc shape factor): poly,spare1,spare2 1.0 0. 0. 0. !Coefficient, power of Tr, power of Dr, spare 1 0 0 !Number of terms in chi (t.c. shape factor): poly,spare1,spare2 1.0 0. 0. 0. !Coefficient, power of Tr, power of Dr, spare NUL !Pointer to critical enhancement auxiliary function ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ #STN !---Surface tension--- ST1 !Surface tension model for R-123 of Mulero et al. (2012). :DOI: 10.1063/1.4768782 ? ?``````````````````````````````````````````````````````````````````````````````` ?Mulero, A., Cachadiņa, I., and Parra, M.I., ? "Recommended Correlations for the Surface Tension of Common Fluids," ? J. Phys. Chem. Ref. Data, 41(4), 043105, 2012. doi: 10.1063/1.4768782 ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 1 !Number of terms in surface tension model 456.831 !Critical temperature used in fit (dummy) 0.056151 1.2367 !Sigma0 and n #PS !---Vapor pressure--- PS5 !Vapor pressure equation for R-123 of Cullimore (2010). ? ?``````````````````````````````````````````````````````````````````````````````` ?Cullimore, I.D., 2010. ? ?Functional Form: P=Pc*EXP[SUM(Ni*Theta^ti)*Tc/T] where Theta=1-T/Tc, Tc and Pc ? are the reducing parameters below, which are followed by rows containing Ni and ti. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 456.831 3661.8 !Reducing parameters 4 0 0 0 0 0 !Number of terms in equation -7.4610 1.0 2.0293 1.5 -2.1897 2.25 -3.4945 4.5 #DL !---Saturated liquid density--- DL1 !Saturated liquid density equation for R-123 of Cullimore (2010). ? ?``````````````````````````````````````````````````````````````````````````````` ?Cullimore, I.D., 2010. ? ?Functional Form: D=Dc*[1+SUM(Ni*Theta^ti)] where Theta=1-T/Tc, Tc and Dc are ? the reducing parameters below, which are followed by rows containing Ni and ti. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 456.831 3.596417 !Reducing parameters 5 0 0 0 0 0 !Number of terms in equation 1.9996 0.345 0.41823 0.74 0.24849 1.2 0.18831 2.6 0.13737 7.2 #DV !---Saturated vapor density--- DV3 !Saturated vapor density equation for R-123 of Cullimore (2010). ? ?``````````````````````````````````````````````````````````````````````````````` ?Cullimore, I.D., 2010. ? ?Functional Form: D=Dc*EXP[SUM(Ni*Theta^ti)] where Theta=1-T/Tc, Tc and Dc are ? the reducing parameters below, which are followed by rows containing Ni and ti. ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 456.831 3.596417 !Reducing parameters 6 0 0 0 0 0 !Number of terms in equation -3.0205 0.3905 -7.4537 1.29 -21.880 3.4 -57.430 7.0 11.239 12.0 -166.40 15.0 @END c 1 2 3 4 5 6 7 8 c2345678901234567890123456789012345678901234567890123456789012345678901234567890 @AUX !---Auxiliary function for the thermal conductivity critical enhancement TK1 !Pure fluid thermal conductivity model for R-123 of Laesecke et al. (1996). ? ?``````````````````````````````````````````````````````````````````````````````` ?Laesecke, A., Perkins, R.A., and Howley, J.B., ? !``````````````````````````````````````````````````````````````````````````````` 0. ! 10000. ! 0. ! 0. ! 1 0 2 0 !# terms: polynomial-numerator, poly-denom, exp, spare -456.831 3.596417 1.0 !Reducing parameters for T, rho, tcx [mW/(m-K)] (-Tc indicates tau = Tred/t), rho (= Dc), tcx in polynomial term 0.00486742 0. 0. 0. 0. 0 ! a13 -456.831 3.596417 1.0 !Reducing parameters for T, rho, tcx [mW/(m-K)] (-Tc indicates tau = Tred/t), rho (= Dc), tcx in exponential term -100.0 -1. 4. 0. 0. 0 ! a14*(tau - 1)**4 -7.08535 0. 0. -1. 2. 0 ! a15*(del - 1)**2