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Basic Absorption Coefficients for UDF macro DEFINE_WSGGM_ABS_COEFF |
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moein vh
Join Date: Aug 2017
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Hi friends,
I wanna use a non-gray model for combustion. As it is mentioned in Fluent Theory Guide, "The weighted-sum-of-gray-gases model (WSGGM) cannot be used to specify the absorption coefficient in each band.", I want to use a UDF to calculate absorption coefficient for each band, separately. I found a macro in Fluent UDF manual which is named DEFINE_WSGGM_ABS_COEFF. An example: Code:
include "udf.h" #include "materials.h" DEFINE_WSGGM_ABS_COEFF(user_wsggm_abs_coeff, c, t, xi, p_t, s, soot_conc, Tcell, nb, ab_wsggm, ab_soot) { Material *m = THREAD_MATERIAL(t); int ico2 = mixture_specie_index(m, "co2"); int ih2o = mixture_specie_index(m, "h2o"); real CO2_molf, H2O_molf; real k2, k3, k4; CO2_molf= xi[ico2]; H2O_molf= xi[ih2o]; switch (nb) { case 0 : /* First gray gas*/ { *ab_wsggm = 0; } break; case 1 : /* Second gray gas*/ { k2 = 0.1; *ab_wsggm = (k2 * (H2O_molf + CO2_molf)) * p_t; } break; case 2 : /* Third gray gas*/ { k3 = 7.1; *ab_wsggm = (k3 * (H2O_molf + CO2_molf)) * p_t; } break; case 3 : /* Fourth gray gas*/ { k4 = 60.0; *ab_wsggm = (k4 * (H2O_molf + CO2_molf)) * p_t; } } *ab_soot = 0.1; } Do you know any reference that could give me the values of basic absorption coefficients (k2, k3, k4) for various infrared and visible bands? Best Regards, Moein Vh |
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Tags |
absorption coefficient, band, non-gray, udf, wsggm |
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