Chemkin-II inputhttp://www.frad.t.u-tokyo.ac.jp/public/chemkin/CKm_inp.html.en back - Chemkin-II input MIYOSHI Group, Univ. Tokyo Chemkin-II inputs This document describes the format of the chemkin-II input files. Contents Chemkin Interpreter input (chem.inp) Input-file structure Elements block Species block Thermo block Reactions block Senkin input (senk.inp) Senkin Binary-CSV converter input (sb2c.inp) Rxn Contrib tool input (rxnc.inp) Thermodynamic data (therm.dat) Chemkin Interpreter input For the complete description of the Chemkin Interpreter input file, see the following document. 'Chemkin-II: A Fortran Chemical Kinetics Package for the Analysis of Gas-Phase Chemical Kinetics,' R. J. Kee, F. M. Rupley, and J. A. Miller, Sandia Report, SAND89-8009B (1995). Input-file structure Below is an example input. !----------------------------------------------------------------------! 'exmHCO01.inp' ! C-H-O system machanism based on ... !----------------------------------------------------------------------ELEMENTS H C N O END !----------------------------------------------------------------------SPECIES H2 H O2 O OH HO2 H2O2 H2O N2 CH3 CH4 ...(snip)... END !----------------------------------------------------------------------THERMO CH3 121286C 1H 3 G 0300.00 5000.00 1000.00 0.02844051E+02 0.06137974E-01-0.02230345E-04 0.03785161E-08-0.02452159E-12 0.16437809E+05 0.05452697E+02 0.02430442E+02 0.11124099E-01-0.01680220E-03 0.16218288E-07-0.05864952E-10 0.16423781E+05 0.06789794E+02 END !----------------------------------------------------------------------REACTIONS KJOULES/MOLE MOLECULES H + CH3 (+M) = CH4 (+M) 3.50E-10 0. 0. !94CEC (300-1000K) LOW /1.726E-24 -1.8 0./ ! for M=Ar TROE /0.63 61. 3315./ ...(snip)... END !----------------------------------------------------------------------The input should be in the following order. The thermo block may be skipped. Elements block 'ELEMENTS' ~ 'END' Species block 'SPECIES' ~ 'END' Thermo block 1 2 3 4 1 sur 9 03/06/2013 08:09 Since thermodynamic functions are required to calculate the rate constants for reverse reactions (See Reactions block) and the heat balance. Chemkin requests the thermodata.html. do not modify the therm.dat is named as 'HCO'.. From the exclamation mark to the end of the line is skipped by the parser as a comment. but register it in here in the Thermo block.u-tokyo. and propyne. A reaction should be described in the order of the reaction equation and rate parameters. not 'CHO') When the chemical formula is not enough to identify the species. place the names of the species delimited by spaces or a line-feed between 'SPECIES' and 'END'. and if you choose to use them. Thermo block This block is an option. Not allowed in the thermo block which is a fixed-format part.dat or thermo block. 'C3H4C'. In such a case.). In an exceptional case. example-1 ELEMENTS H O AR CL END example-2 ELEMENTS H O C N HE END Species block List all the species (atoms and molecules) to be considered. The species name cannot exceed 16 charactors.dat with dummy data.en 'THERMO' ~ 'END' Reactions block 'REACTIONS' ~ 'END' At any position in the format-free part. (For example. and 'C3H4P' corresponding to allene.jp/public/chemkin/CKm_inp.dat) section for details. Place the symbols of elements delimited by a space (may be multiple spaces) or a line-feed between 'ELEMENTS' and 'END'.dat.t.frad.g. even for the isothermic calculation without any reversible reaction. Reaction equation A reaction equation can be given as the following format. lower. It does not need to be a chemcal formula such as CH4' or 'C2H6'. The format is identical with that of therm. and the first letter should not be numeric. Elements block List all the elements contained in the species (that is. reac1 + reac2 + reac3 = prod1 + prod1 + prod3 The number of the reactants or the products must be no less than one and no more than three. nor '='. When the all species in the Species Block are registered in the therm. '+'. thermodynamic data should be given for all the species considered. They are named as 'C3H4'. but should be identical with the name in the therm. Place the coefficients for thermodynamic functions in four-lines fixed-format per one species between 'THERMO' and 'END'. The 'REACTIONS' or 'END' statement should appear as an independent line. Similarly to the elements. this block can be skipped. The name of the reactant or product must be identical with the one declared in the Species Block except for the following exceptions. atoms and molecules) to be considered. For example. an exclamation mark. there are three species with C3H4 chemcal formula in therm. For this case. either of upper. 'AR' 'ar' or 'Ar') is allowed but it must be case-sensitively identical with that used in the thermodata. '!'. However. formyl radical in the default therm.Chemkin-II input http://www.dat. exception-1 A reaction with two or more identical reactants or products may be written as the following example. refer to The Chemkin Thermodynamic Data Base (SAND87-8215B). cyclopropene. Reactions block List reaction equations with rate parameters for the reactions to be considered in this block. and one reaction should be described in a line. respectively..ac. With Chemkin. one may register dummy (may be totally inaccurate) thermodata to avoid the error of Chemikin. 2OH = H2O2 2 sur 9 03/06/2013 08:09 . can be inserted. For element symbols. or mixed case (e.dat and refer to the Thermodata file (therm. when no reverse reaction should be considered and the temperature change can be negligible (which may no be rare as the condition of the laboratory kinetic experiments . thermodynamic data is not necessary. => Indicates an irreversible reaction. No choice for the unit such as mol/l (= mol dm−3). (2) where X is a reduce pressure normalized by the fall-off pressure [M]c. MOLES) or molecules-cm-s-K (MOLECULES). The acceptable keywords are as follows. two keywords specifying units for the activation energy and preexponential factor may placed after 'REACTIONS' delimited with space charactors.ac. and Ea should be specified in this order separated by space charactors. KJOULES/MOLE. Auxiliary input is required to specify the formula for the pressure dependence. Lindemann formula Evaluate the pressure dependence by using the Lindemann formula. In the top line of the Reactions Block. The following auxiliary inputs are accepted.t. The rate constant for the reverse reaction is calculated from the thermodynamic data unless it is specified by using REV keyword. H + H + M = H2 + M Details of the reactions with third-body will be given below. In scientific papers. The Chemkin input form is a convenience to clarify the way to calculate the pressure dependence of the rate constants and do not confuse.3 / Troe's formula Evaluate the pressure dependence by using the Troe's formula. KELVINS MOLES. The default is cal/mol for the activation energy and mol-cm-s-K for the preexponential factor. and Ea for the high-pressure limit in the reaction equation line.6 -54.html. Auxiliary input for the pressure dependence is required when the form-3 above is specified. that is. the reaction involving the third-body always written with the apparent 'M' irrespective of the pressure dependence of the rate constant. b.2 LOW/ 6. 3 sur 9 03/06/2013 08:09 . on of the following three forms is used. only the forward reaction is considered. (3). (4) Write A.jp/public/chemkin/CKm_inp. KCAL/MOLE. CAL/MOLE. = or <=> Indicates an reversible reaction. JOULES/MOLE.Chemkin-II input http://www. A + B (+ M) = C (+ M) 2. Reactions involving third-body Depending on how the rate constants changes with the pressure. The rate parameters for the low-pressure limit should be given in the next line by using LOW keyword as follows.frad.0 156. (1) The parameters. form-3 A + B (+ M) => C (+ M) Rate constant is in the fall-off region. It may be used as the following example.3E27 -2.en exception-2 M is a special third-body reactant (and product) representing the all the species. form-2 A + B + M => C + M Rate constant is assumed to be in low-pressure limiting region. One of the following separators can be used between the reactants and products. form-1 A + B => C Rate constant is considered to be independent of pressure. A. b. MOLECULES The unit for the preexponential factor may be either mol-cm-s-K (default. Rate constants and unit Rate constants are calculated by the modified Arrhenius equation.3E14 0.u-tokyo. 1. Place 'END' indicating the end of input in the last line.' (period). SAND87-8248 (1995). and J.3 CO/1. Similar input can be added for the fall-off reactions.6 -54. Miller. Lutz. H2. the problem selection keyword described below will appear at the first line. 3.7.t.3 / TROE/ 0. A. the rate parameters for the low-pressure limit or the low-pressure part of the fall-off region depends largely on the buffer gas. Sample input A sample input is shown below. Below is an example.html.3E27 -2. give the rate parameters for high-pressure and low-pressure limits in the first and second lines. A + B (+ M) = C (+ M) 2. the low-pressure limiting rate constant is multiplied by 1. and H2O. '/' (slash). and in the third line. 132.7/ CO2/3.ac. Senkin inputs For the complete description of the Senkin input file format./ H2O/5. A + B + M = C + M 6. See the following document. / In general. respectively.E-4 1. place 'SENS' in the first line. in this order by using TROE keyword. Lines beginning with '. J.9/ H2/1./ In this example. T**. Sensitivity option To perform the sensitivity analysis.frad.E-4 H2 2 O2 1 N2 4 Place one keyword per line.6 -54. SENS CONP PRES TEMP TIME DELT REAC REAC REAC END 1. R. The last parameter. T*.Chemkin-II input http://www. give the parameters a.9. T***.u-tokyo. CO2.0 156. or '!' (exclamation mark) are skipped as comments. Space character cannot be inserted at the beginning of a line. and T**. When no sensitivity analysis is needed.604 6980. 2.jp/public/chemkin/CKm_inp.3E14 0. (10) will be omitted when this parameter is omitted..' A.0 1000. Problem selection One (and only one) of the problem selection keyword is necessary at the first input except for the 'SENS' keyword. 'SENKIN: A Fortran Program for Predicting Homogeneous Gas Phase Chemical Kinetics with Sensitivity Analysis. Kee. The acceptable keywords are as follows.2 LOW/ 6. Sandia Report. Here is an example. This effect can be specified as an enhancement factor.3E27 -2. CONP CONstant Pressure & adiabatic 4 sur 9 03/06/2013 08:09 . for CO.en (5) (6) (7) (8) (9) (10) Similarly to the case of Lindemann formula. is optional and the last term of eq. E. and 5. REST Restart The initial condition will be read from the rest. results for all integration steps are stored.html. TIME Final time [s] for integration DELT Time interval [s] for the console and tign.bin. PRES. irrespective of this parameter. (Default : 1E-5) RTLS TLIM Ignition criterial temperature (Default : initial temperautre + 400 K) ICEN options When the 'ICEN' is selected for the problem. May present as many as needed.bin.4 Rotation speed [rpm] (Default : 1500) Ratio of connecting rod length to crank radius (Default : 3) 5 sur 9 03/06/2013 08:09 . The name must be registered in the Species Block of chem. Absolute tolerance of variables. For details. and PRGT are extended keywords which are not valid in the original Senkin. the initial time for restart is read from the rest. the soubroutine VOLT or TEMPT in the senkin driver (skdriver.f) must be properly written so as it calculates the volume or the temperature. at a given time. Use if required. It should be noted that the mass fraction of chemical species is integrated in the senkin. CGME. The keywords TEMP.en CONV CONT ICEN CONstant Volume & adiabatic CONstant Temperature & constant pressure Internal Combustion ENgine (zero-dimensional) – Adiabatic compression and expansion with a constant speed crank-piston mechanism. Integration control The following keywords can be used to control the integration (required). see ICEN Extension to SENKIN Code (pdf). Options Keywords for restart. CMPR K RPM N LOLR R Compression Ratio Ratio of the maximum cylinder volume to minimum volume. respectively. respectively.u-tokyo. Initial time [s] for restart Usually. # When the 'VTIM' or 'TTIM' is specified. Default is 1E-20.t.jp/public/chemkin/CKm_inp. CGME Core Gas Model Extention – Core gas model calculation for a rapid compression machine. Initial conditions The following keywords can be used to specify the initial consitions (required). VTIM# Volume as a function of TIMe & adiabatic PRGT* PRoGrammed Temperature & constant pressure TTIM# Temperature as a function of TIMe & constant pressure * ICEN. TEMP Initial temperature [K] PRES REAC Initial pressure [atm] Name of the reactant and moles. and REAC are no longer necessary and are ignored if present. The keywords below may be placed at any line between the problem selection keyword and 'END'.out output. precision of the integration.Chemkin-II input http://www. In save.frad. etc. (Default : 1E-8) ATLS Absolute and relative tolerance of sensitivity coefficients.ac. The mole fractions will be normalized in senkin. This may be changed by the 'TRES' keyword. TRES ATOL RTOL Relative tolerance of variables.inp.bin. the following options may be specified. Default is 18. and cylinder wall temperature. V−1 is quadratic. When the following CCVC option is NOT specified. Parameters for the volume change after the compression (Core-Gas Model Coefficients for Volume Function) The virtual volume change after compression by core gas model is approximated by the following empirical equation. When this option is specified.frad. respectively.jp/public/chemkin/CKm_inp.html. the volume is the core-gas model volume divided by the initial volume before compression. Parameters for the volume change during the compression (Core-Gas Model Coefficients for Volume Change during Compression) The virtual volume change during the compression by core gas model is approximated by the following empirical equations.ac. V−1 is approximated by the decay function specified by CCVF. Vi ) pairs at the switching points of the function forms.Chemkin-II input http://www. (Default : 100 cm3) Initial crank angle [Unit: degree / TDC = 0] (Default : 180°) Heat loss parameters Give the coefficients for the relation of Nusselt number with the Reynolds and Prandtl numbers. 6 sur 9 03/06/2013 08:09 . After t4. the calculation starts from the temperature and pressure of the compressed gas specified by TEMP and PRES. k 1 ~ k 3) are also used. Tw [K]. CCVF c1 k1 c2 k 2 c3 k 3 V−1 ∝ c1exp(−k 1t) + c2exp(−k 2t) + c3exp(−k 3t) + 1 Note that only the relative change of volume is needed and the last term can always be given as unity. B [cm]. The unit of k i is s−1. In the fourth part. The unit of the time t is s [second]. the initial temperature (TEMP) and pressure (PRES) should be those before the compression. When no heat loss is considered. It should be noted that the cylinder surface area is calculate by using Vc. except for the output of the total mass. The time = 0 should be defined so that the V−1 in the first part can be well approximated by a quadratic.u-tokyo. V and V−1 are approximated by straight lines. It should be unity (1) at time = 0. and should also be specified by the CCVF option.en VOLC Vc DEG0 θ0 Clearance volume [cm3] Cylinder volume at the TDC (top dead center).t. CCVC option specifies (ti . In the second and third parts. this value does not affect the calculation essentially. The profile of the volume change specified by the CCVC and CCVF options is shown in the figure to the right. the following optional parameters may be specified. In these equations. CGME options When the 'CGME' is selected as a problem. ICHT a m n B Tw Nu = a Re m Pr n cylinder bore. t<0: 0≤t< t1 : t1 ≤ t < t2 : t2 ≤ t < t3 : t3 ≤ t < t4 : CCVC t1 V1 t2 V2 t3 V3 t4 V4 t4 ≤ t : V=1 V−1 = b1t2 + 1 V = b2(t − t1) + V1 V−1 = b3(t − t2) + V2−1 V−1 = b4(t − t4)2 + V4−1 V = b5 / [c1exp(−k 1t') + c2exp(−k 2t') + c3exp(−k 3t') + 1] where t' = t − t4 b1 = (V1−1 − 1) / t12 b2 = (V2 − V1) / (t2 − t1) b3 = (V3−1 − V2−1) / (t3 − t2) b4 = (V3−1 − V4−1) / (t3 − t4)2 b5 = V4(c1 + c2 + c3 + 1) The parameters for the valume change after the compression (c1 ~ c3. Senkin binary-CSV coverter input Example input An example input is shown below.ac. the species names are case sensitive. but should not be deleted. One of the followings can be specified as the unit of time. they are not always necessary. Although the save.Chemkin-II input http://www. specify the control parameters. TIME OUTPUT CONTROL (one line) Specify the unit of the time output and the frequency of the output. Such a control can be done with atol and rtol.05 all selonly none molecules/cc molefrac ] all none (or species name list) ] In three blocks (TIME OUTPUT CONTROL. The first line and the lines beginning with '[' are comment lines and may be modified.frad.t.en PRGT option When the 'PRGT' is selected as a problem. The temperature at time = 0 is always the temperature specified by the 'TEMP' keyword. the resolution of the abscissa is limited to certain value. default is 's' (seconds). the time t of this option cannot be 0 or negative. for example for plotting. CONC OUTPUT CONTROL.html. ===== sb2c (sbin2csv. for example. s seconds ms milliseconds 7 sur 9 03/06/2013 08:09 . for the plotting. When the variation of the variables (mostly concentrations) is small. Since the converting all the time steps into CSV files often results in an extremely large file size and/or slow plotting. Temperature Point Gives the temperature T [K] at the time t [s].u-tokyo. SENS OUTPUT CONTROL). The temperature profile can be specified by using multiple TPNT t T 'TPNT' options. the output interval may be large. Therefore. Though the keywords are case insensitive.f) [ TIME OUTPUT CONTROL: us mind=1e-6 maxd=1e-5 [ CONC OUTPUT CONTROL: molecules/cc selonly H O OH HO2 H2 O2 [ SENS OUTPUT CONTROL: H O TEMP Control file ===== (s ms us) atol=# rtol=# mind=# maxd=# sent=# ] atol=1e-15 rtol=. they are skipped properly. Also. the following optional parameter may be specified. the temperatures between points are given by linear interpolation. The skipping is controlled by the parameters here. When omitted.bin contains the all the results for every integration steps.jp/public/chemkin/CKm_inp. The minimum time resolution is controlled by mind. With PRGT extension. and temperature. When omitted. (leave 'none'. concentrations of only H.u-tokyo. none none (output is generated for temperature and pressure) selonly selected species only all all the species The second line is allowed only when the selonly is specified in the first line. Absolute tolerance The species with mole fractions less than atol is not considered for the output frequency control. Variable names are the speceis names or 'TEMP' (temperature).html. all as below. for example. When omitted. The following units can be accepted. OH. the output interval is controlled to be smaller than or equal to maxd maxd. O. For example. HO2.05 sets the relative torelance to be 5%. species with mole fraction less than 1×10−15 are ignored in the output frequency determination.inp. For example. ] 2.0E+03 (1000 seconds) is adopted.frad. default is 0. (Default : molecules/cc). with atol=1e-15. Maximum ∆t (Unit: seconds) Irrespective of atol or rtol.0E-16.jp/public/chemkin/CKm_inp.en us microseconds Following output controls can be specified. ===== rxnc (rxncntrb. mind=5e-6 forces the minimum output interval to be 5 microseconds. In the example above.5e-4 1.ac. the sensitivity output is generated only for the specified time point. H2. In the example above. the output interval is controlled to be larger than or equal to mind mind.Chemkin-II input http://www. If omitted. and O2 are output in molecules cm−3 unit.e-6 8 sur 9 03/06/2013 08:09 .) none no output all output for all the variables Rxn Contrib tool input Example Below is an example. time2..1 (10%).78e-4 5e-5 1. dafault value 1. Though this input is meaningful only when the 'SENS' is specified in senk. . (Default : 'all'). rtol=. or list the variable names delimited by spaces. List the name of species delimied by spaces in the second line. For example. default is 1.. molecules/cc molecules cm−3 molefrac mole fraction One of the following species output control can be specified. atol rtol Minimum ∆t (Unit: seconds) Irrespective of atol or rtol.f) Control Input File ===== [ (Time points to be investigated in s) time1. SENS OUTPUT CONTROL (one line) Specify none. It should be noted that the minimum output interval is determined by the internal time integration step. Time for sensitivity output (Unit: seconds) Sensitivity output is generated for the all time points that satisfy the other output control options without this option. sensitivity coefficients are output for the species H and O.t. Relative tolerance The output is done when the relative change of the any of the variable exceeds rtol from the last output. When this option is specified. If not specified. but should never be deleted in other cases. sent CONC OUTPUT CONTROL (one or two line[s]) Specify the unit of concentration output and the species to be output. dafault value 1.0E-05 (10 microseconds) is adopted. The thermodynamic data consist of a1. 1E-20. that is. The first line consist of the name of the chemcial species. Default is save. respectively.00000000E+00 0. the time to be analyzed is specified in the unit of seconds. 300~1000 K and 1000~5000 K.en [ (species to be investigated) name1.bin The third. and seventh lines specifies the time. sbin=file name specifies the file name of the senkin binary to be read.Chemkin-II input http://www. Input the same number as in the senkin input. see the document shown above.frad. top#=n (integer) List the top n reactions with highest contribution.t. name2.00000000E+00 0. Thermodynamic data For the complete description of the thermodynamic data format. When this option is specified.02500000E+02 0. A.00 1000. Sandia Report.jp/public/chemkin/CKm_inp. two sets of the coefficients are prepared for two temperature ranges.. a2.02500000E+02 0.00000000E+00 0. the contribution output is also generated in the .1 sbin=save. For details. Multiple values are allowed.00 5000. and J. Thermodynamic functions are represented with the NASA polynomials. species.00 0.04366000E+02 1 2 3 4 9 sur 9 03/06/2013 08:09 . M.00000000E+00-0.html.u-tokyo. AR 120186AR 1 G 0300.00000000E+00 0.. ] H O HO2 [ options (atol.. In the option line. See the following document. F. min%=r (real) atol=ATOL ocsv List the reactions with the contribution no less than r %. (11) (12) (13) Usually. Kee.bin.00000000E+00 0. chemical formula etc.00000000E+00 0.04366000E+02 0.00000000E+00 -0. Default is the default adopted by senkin. 'The Chemkin Thermodynamic Data Base.' R. top#.07453750E+04 0. . Rupley.csv files.ac. Miller. a7 for high temperature and those for low temperature (totally 14 coefficients). In the time specification.. min%. following input with the form of keyword=value can be accepted. In the species line. Below is an example.07453750E+04 0.. ocsv) ] atol=1e-20 min%=0. SAND87-8215B (1994). J. fifth. . sbin. the names of the chemical species must be listed. and option.