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Hello everybody, I’m working on a simulation of a tubular reactor for secondary reforming. Since my 3D simulation run resulted in error, I decided to face the same situation with a 1D model, but the error is the same. I have to define a temperature-dependent kynetic, so I attached to the simulation 2 physics, which are “transport of diluted species in porous media” and “heat transfer in porous media”. I checked that all the empty sections were filled out, but I didn’t find anything wrong. The kinetics for steam reforming are quite difficult, so I tried to check them, but I could not have seen some error in the variables. The error after "compute" is:

Feature: Stationary Solver 1 (sol1/s1) Attempt to evaluate nonintegral power of negative number. - Function: ^ Failed to evaluate variable. - Variable: B1 - Defined as: 1/(((comp1.cH2(unit_m_cf^3))/unit_mol_cf)^2.5) Failed to evaluate variable. - Variable: cost1 - Defined as: ((A1B1)(unit_m_cf^6))/((unit_kg_cfunit_h_cf)unit_mol_cf) Failed to evaluate variable. - Variable: cost1_1 - Defined as: cost1/(DEN^2) Failed to evaluate variable. - Variable: r1_ - Defined as: cost1_1((comp1.cCH4comp1.cH2O)-(((comp1.cCO(comp1.cH2^3))((comp1.TR)^2))/Keq1)) Failed to evaluate variable. - Variable: r1 - Defined as: r1_rhocat Failed to evaluate variable. - Variable: comp1.tds.rpb1.reac1.R_cCH4 - Defined as: (-r1)-r3 Failed to evaluate variable. - Variable: comp1.tds.rpb1.R_cCH4 - Defined as: comp1.tds.rpb1.reac1.R_cCH4 Failed to evaluate expression. - Expression: d(((4picomp1.tds.rpb1.Npecomp1.tds.rpb1.rperpb1_r^2(-(comp1.tds.rpb1.rpe/unit_m_cf)^2comp1.tds.rpb1.epsilon_ped(comp1.tds.rpb1.cpe_cCH4,t)test(comp1.tds.rpb1.cpe_cCH4)-comp1.tds.rpb1.Dpeff_cCH4d(comp1.tds.rpb1.cpe_cCH4,rpb1_r)test(d(comp1.tds.rpb1.cpe_cCH4,rpb1_r))+(comp1.tds.rpb1.rpe/unit_m_cf)^2comp1.tds.rpb1.R_cCH4test(comp1.tds.rpb1.cpe_cCH4)))(tds_rpb1_xdim.atonly(dvol)))(dvol_spatial),{test@0}) Failed to evaluate Jacobian of expression. - Expression: ((4picomp1.tds.rpb1.Npecomp1.tds.rpb1.rperpb1_r^2(-(comp1.tds.rpb1.rpe/unit_m_cf)^2comp1.tds.rpb1.epsilon_ped(comp1.tds.rpb1.cpe_cCH4,t)test(comp1.tds.rpb1.cpe_cCH4)-comp1.tds.rpb1.Dpeff_cCH4d(comp1.tds.rpb1.cpe_cCH4,rpb1_r)test(d(comp1.tds.rpb1.cpe_cCH4,rpb1_r))+(comp1.tds.rpb1.rpe/unit_m_cf)^2comp1.tds.rpb1.R_cCH4test(comp1.tds.rpb1.cpe_cCH4)))(tds_rpb1_xdim.atonly(dvol)))*(dvol_spatial)

I also changed the initial values, because in some forums I have read that values equal to 0 sometimes give rise to errors, but my error is persistent. I attach my file in order to let you understand better my study and my errors. Thank you in advance for your help, your help could be really important!