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January 24, 2022, 06:03 |
Error with Peng-Robinson EoS
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New Member
Nicola Fontana
Join Date: Nov 2021
Posts: 8
Rep Power: 4 |
Hi everyone. I'm simulating a stage of a turbine to make a comparison between air and carbon dioxide as working fluid. When I run the simulation with air everything is ok and the program reach the last iteration and end with "Exit succes".
For what regards carbon dioxide, I decided to use Peng-Robinson (any suggestions on how to best model carobn dioxide is welcome) and I setted the properties as follows, without changing any other settings: Code:
% ------------------------------ sCO2 -----------------------------------------% % Different gas model (STANDARD_AIR, IDEAL_GAS, VW_GAS, PR_GAS) FLUID_MODEL= PR_GAS % Ratio of specific heats (1.4 default and the value is hardcoded % for the model STANDARD_AIR) GAMMA_VALUE= 1.29 % Specific gas constant (287.058 J/kg*K default and this value is hardcoded % for the model STANDARD_AIR) GAS_CONSTANT= 188.92 % Critical Temperature (273.15 K by default) CRITICAL_TEMPERATURE= 304.25 % Critical Pressure (101325.0 N/m^2 by default) CRITICAL_PRESSURE= 7377300 % Acentri factor (0.035 (air)) ACENTRIC_FACTOR= 0.22394 % --------------------------- VISCOSITY MODEL ---------------------------------% % Viscosity model (SUTHERLAND, CONSTANT_VISCOSITY). VISCOSITY_MODEL= CONSTANT_VISCOSITY %VISCOSITY_MODEL= SUTHERLAND % Molecular Viscosity that would be constant (1.716E-5 by default) MU_CONSTANT= 1.3764E-5 % Sutherland Viscosity Ref (1.716E-5 default value for AIR SI) %MU_REF= 1.376E-5 % Sutherland Temperature Ref (273.15 K default value for AIR SI) %MU_T_REF= 273.15 % Sutherland constant (110.4 default value for AIR SI) %SUTHERLAND_CONSTANT= 222 % --------------------------- THERMAL CONDUCTIVITY MODEL ----------------------% % Conductivity model (CONSTANT_CONDUCTIVITY, CONSTANT_PRANDTL). CONDUCTIVITY_MODEL= CONSTANT_CONDUCTIVITY % Molecular Thermal Conductivity that would be constant (0.0257 by default) THERMAL_CONDUCTIVITY_CONSTANT= 0.028 After this change, the program print this message at every step since the first iteration: Code:
Root must be bracketed for bisection in rtbis Too many bisections in rtbis TD consistency not verified in hs call With the inelt condition setted, carbon dioxide should be in the supercritical region, could this be the problem, or anyone have any suggestion on why this happens? The configuration file is the following: Code:
% SU2 configuration file % % Case description: 2D Axial stage % % Author: N. Fontana % % Institution: % % Date: Jan 12th, 2022 % % File Version 7.2.0 "Blackbird" % % % %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% % % Enable multizone mode MULTIZONE= YES % % List of config files CONFIG_LIST= (zone_1.cfg, zone_2.cfg) % % ------------- DIRECT, ADJOINT, AND LINEARIZED PROBLEM DEFINITION ------------% % % Physical governing equations (EULER, NAVIER_STOKES, % WAVE_EQUATION, HEAT_EQUATION, LINEAR_ELASTICITY, % POISSON_EQUATION) SOLVER= RANS % % Specify turbulent model (NONE, SA, SST) KIND_TURB_MODEL= SST % % Mathematical problem (DIRECT, ADJOINT, LINEARIZED) MATH_PROBLEM= DIRECT % % Restart solution (NO, YES) RESTART_SOL= NO % % % -------------------- COMPRESSIBLE FREE-STREAM DEFINITION --------------------% % % Mach number (non-dimensional, based on the free-stream values) MACH_NUMBER= 0.3 % % Angle of attack (degrees, only for compressible flows) AOA= 0.0 % % Free-stream pressure (101325.0 N/m^2 by default, only Euler flows) FREESTREAM_PRESSURE= 10000000.0 % % Free-stream temperature (273.15 K by default) FREESTREAM_TEMPERATURE= 500.0 % % Free-stream temperature (1.2886 Kg/m3 by default) FREESTREAM_DENSITY= 2 % % Free-stream option to choose if you want to use Density (DENSITY_FS) or Temperature (TEMPERATURE_FS) to initialize the solution FREESTREAM_OPTION= TEMPERATURE_FS % % Free-stream Turbulence Intensity FREESTREAM_TURBULENCEINTENSITY = 0.03 % % Free-stream Turbulent to Laminar viscosity ratio FREESTREAM_TURB2LAMVISCRATIO = 100.0 % %Init option to choose between Reynolds (default) or thermodynamics quantities for initializing the solution (REYNOLDS, TD_CONDITIONS) INIT_OPTION= TD_CONDITIONS % % ---------------------- REFERENCE VALUE DEFINITION ---------------------------% % % Reference origin for moment computation REF_ORIGIN_MOMENT_X = 0.00 REF_ORIGIN_MOMENT_Y = 0.00 REF_ORIGIN_MOMENT_Z = 0.00 % % Reference length for pitching, rolling, and yawing non-dimensional moment REF_LENGTH= 1.0 % % Reference area for force coefficients (0 implies automatic calculation) REF_AREA= 1.0 % % % Flow non-dimensionalization (DIMENSIONAL, FREESTREAM_PRESS_EQ_ONE, % FREESTREAM_VEL_EQ_MACH, FREESTREAM_VEL_EQ_ONE) REF_DIMENSIONALIZATION= DIMENSIONAL % % %------------------------------------------------------------------------------% % ------------------------------ sCO2 -----------------------------------------% %------------------------------------------------------------------------------% % Different gas model (STANDARD_AIR, IDEAL_GAS, VW_GAS, PR_GAS) FLUID_MODEL= PR_GAS % Ratio of specific heats (1.4 default and the value is hardcoded % for the model STANDARD_AIR) GAMMA_VALUE= 1.29 % Specific gas constant (287.058 J/kg*K default and this value is hardcoded % for the model STANDARD_AIR) GAS_CONSTANT= 188.92 % Critical Temperature (273.15 K by default) CRITICAL_TEMPERATURE= 304.25 % Critical Pressure (101325.0 N/m^2 by default) CRITICAL_PRESSURE= 7377300 % Acentri factor (0.035 (air)) ACENTRIC_FACTOR= 0.22394 % --------------------------- VISCOSITY MODEL ---------------------------------% % Viscosity model (SUTHERLAND, CONSTANT_VISCOSITY). VISCOSITY_MODEL= CONSTANT_VISCOSITY %VISCOSITY_MODEL= SUTHERLAND % Molecular Viscosity that would be constant (1.716E-5 by default) MU_CONSTANT= 1.3764E-5 % Sutherland Viscosity Ref (1.716E-5 default value for AIR SI) MU_REF= 1.376E-5 % Sutherland Temperature Ref (273.15 K default value for AIR SI) MU_T_REF= 273.15 % Sutherland constant (110.4 default value for AIR SI) SUTHERLAND_CONSTANT= 222 % --------------------------- THERMAL CONDUCTIVITY MODEL ----------------------% % Conductivity model (CONSTANT_CONDUCTIVITY, CONSTANT_PRANDTL). CONDUCTIVITY_MODEL= CONSTANT_CONDUCTIVITY % Molecular Thermal Conductivity that would be constant (0.0257 by default) THERMAL_CONDUCTIVITY_CONSTANT= 0.028 % % -------------------- BOUNDARY CONDITION DEFINITION --------------------------% % % Navier-Stokes wall boundary marker(s) (NONE = no marker) MARKER_HEATFLUX= ( wall1, 0.0, wall2, 0.0) % % Periodic boundary marker(s) (NONE = no marker) % Format: ( periodic marker, donor marker, rot_cen_x, rot_cen_y, rot_cen_z, rot_angle_x-axis, rot_angle_y-axis, rot_angle_z-axis, translation_x, translation_y, translation_z) MARKER_PERIODIC= ( periodic1, periodic2, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.04463756775, 0.0, periodic3, periodic4, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.0, 0.04463756775, 0.0) % % %-------- INFLOW/OUTFLOW BOUNDARY CONDITION SPECIFIC FOR TURBOMACHINERY --------% % % Inflow and Outflow markers must be specified, for each blade (zone), following the natural groth of the machine (i.e, from the first blade to the last) MARKER_TURBOMACHINERY= (inflow, outmix, inmix, outflow) % % Mixing-plane interface markers must be specified to activate the transfer of information between zones MARKER_MIXINGPLANE_INTERFACE= (outmix, inmix) % % Giles boundary condition for inflow, outfolw and mixing-plane % Format inlet: ( marker, TOTAL_CONDITIONS_PT, Total Pressure , Total Temperature, Flow dir-norm, Flow dir-tang, Flow dir-span, under-relax-avg, under-relax-fourier) % Format outlet: ( marker, STATIC_PRESSURE, Static Pressure value, -, -, -, -, under-relax-avg, under-relax-fourier) % Format mixing-plane in and out: ( marker, MIXING_IN or MIXING_OUT, -, -, -, -, -, -, under-relax-avg, under-relax-fourier) MARKER_GILES= (inflow, TOTAL_CONDITIONS_PT, 22000000, 800, 1.0, 0.0, 0.0,1.0,1.0, outmix, MIXING_OUT, 0.0, 0.0, 0.0, 0.0, 0.0,1.0,1.0, inmix, MIXING_IN, 0.0, 0.0, 0.0, 0.0, 0.0,1.0, 1.0 outflow, STATIC_PRESSURE, 8000000.00, 0.0, 0.0, 0.0, 0.0,1.0,1.0) % %YES Non reflectivity activated, NO the Giles BC behaves as a normal 1D characteristic-based BC SPATIAL_FOURIER= NO % % %---------------------------- TURBOMACHINERY SIMULATION -----------------------------% % % Specify kind of architecture (AXIAL, CENTRIPETAL, CENTRIFUGAL, CENTRIPETAL_AXIAL) TURBOMACHINERY_KIND= AXIAL AXIAL % % Specify option for turbulent mixing-plane (YES, NO) default NO TURBULENT_MIXINGPLANE= YES % % Specify ramp option for Outlet pressure (YES, NO) default NO RAMP_OUTLET_PRESSURE= NO % % Parameters of the outlet pressure ramp (starting outlet pressure, updating-iteration-frequency, total number of iteration for the ramp) RAMP_OUTLET_PRESSURE_COEFF= (140000.0, 10.0, 2000) % % Specify Kind of average process for linearizing the Navier-Stokes equation at inflow and outflow BC included mixing-plane % (ALGEBRAIC, AREA, MASSSFLUX, MIXEDOUT) default AREA AVERAGE_PROCESS_KIND= MIXEDOUT % % Specify Kind of average process for computing turbomachienry performance parameters % (ALGEBRAIC, AREA, MASSSFLUX, MIXEDOUT) default AREA PERFORMANCE_AVERAGE_PROCESS_KIND= MIXEDOUT % %Parameters of the Newton method for the MIXEDOUT average algorithm (under relaxation factor, tollerance, max number of iterations) MIXEDOUT_COEFF= (1.0, 1.0E-05, 15) % % Limit of Mach number below which the mixedout algorithm is substituted with a AREA average algorithm AVERAGE_MACH_LIMIT= 0.05 % % % ------------------------ SURFACES IDENTIFICATION ----------------------------% % % Marker(s) of the surface in the surface flow solution file MARKER_PLOTTING= (wall1, wall2) % % ------------- COMMON PARAMETERS DEFINING THE NUMERICAL METHOD ---------------% % % Numerical method for spatial gradients (GREEN_GAUSS, WEIGHTED_LEAST_SQUARES) NUM_METHOD_GRAD= WEIGHTED_LEAST_SQUARES % % Courant-Friedrichs-Lewy condition of the finest grid CFL_NUMBER= 10.0 % % Adaptive CFL number (NO, YES) CFL_ADAPT= NO % % Parameters of the adaptive CFL number (factor down, factor up, CFL min value, CFL max value ) CFL_ADAPT_PARAM= ( 1.3, 1.2, 1.0, 10.0) % % ------------------------ LINEAR SOLVER DEFINITION ---------------------------% % % Linear solver or smoother for implicit formulations (BCGSTAB, FGMRES, SMOOTHER) LINEAR_SOLVER= FGMRES % % Preconditioner of the Krylov linear solver (ILU, LU_SGS, LINELET, JACOBI) LINEAR_SOLVER_PREC= LU_SGS % % Min error of the linear solver for the implicit formulation LINEAR_SOLVER_ERROR= 1E-4 % % Max number of iterations of the linear solver for the implicit formulation LINEAR_SOLVER_ITER= 10 % % % -------------------------- MULTIGRID PARAMETERS -----------------------------% % % ----------- NOT WORKING WITH PERIODIC BOUNDARY CONDITIONS !!!!! --------------% % % % ----------------------- SLOPE LIMITER DEFINITION ----------------------------% % % Coefficient for the limiter VENKAT_LIMITER_COEFF= 0.05 % % Freeze the value of the limiter after a number of iterations LIMITER_ITER= 999999 % % % -------------------- FLOW NUMERICAL METHOD DEFINITION -----------------------% % % Convective numerical method (JST, LAX-FRIEDRICH, CUSP, ROE, AUSM, HLLC, % TURKEL_PREC, MSW) CONV_NUM_METHOD_FLOW= ROE % % Spatial numerical order integration (1ST_ORDER, 2ND_ORDER, 2ND_ORDER_LIMITER) MUSCL_FLOW= YES % % Slope limiter (VENKATAKRISHNAN, VAN_ALBADA_EDGE) SLOPE_LIMITER_FLOW= VAN_ALBADA_EDGE % % Entropy fix coefficient (0.0 implies no entropy fixing, 1.0 implies scalar artificial dissipation, 0.001 default) ENTROPY_FIX_COEFF= 0.01 % % 2nd and 4th order artificial dissipation coefficients JST_SENSOR_COEFF= ( 0.5, 0.02 ) % % Time discretization (RUNGE-KUTTA_EXPLICIT, EULER_IMPLICIT, EULER_EXPLICIT) TIME_DISCRE_FLOW= EULER_IMPLICIT % -------------------- TURBULENT NUMERICAL METHOD DEFINITION ------------------% % % Convective numerical method (SCALAR_UPWIND) CONV_NUM_METHOD_TURB= SCALAR_UPWIND % % Monotonic Upwind Scheme for Conservation Laws (TVD) in the turbulence equations. % Required for 2nd order upwind schemes (NO, YES) MUSCL_TURB= NO % % Slope limiter (VENKATAKRISHNAN, MINMOD) SLOPE_LIMITER_TURB= VENKATAKRISHNAN % % Time discretization (EULER_IMPLICIT) TIME_DISCRE_TURB= EULER_IMPLICIT % % Reduction factor of the CFL coefficient in the turbulence problem CFL_REDUCTION_TURB= 1.0 % % % --------------------------- CONVERGENCE PARAMETERS --------------------------% % Number of total iterations OUTER_ITER= 6000 % Min value of the residual (log10 of the residual) CONV_RESIDUAL_MINVAL= -12 % Start convergence criteria at iteration number CONV_STARTITER= 10 % Number of elements to apply the criteria CONV_CAUCHY_ELEMS= 100 % Epsilon to control the series convergence CONV_CAUCHY_EPS= 1E-6 % ------------------------- INPUT/OUTPUT INFORMATION --------------------------% % Mesh input file MESH_FILENAME= mesh_axial_stage_2d_turb.su2 % Mesh input file format (SU2, CGNS, NETCDF_ASCII) MESH_FORMAT= SU2 % Mesh output file MESH_OUT_FILENAME= meshout.su2 % Restart flow input file SOLUTION_FILENAME= solution_flow.dat % Restart adjoint input file SOLUTION_ADJ_FILENAME= solution_adj.dat % Output file format (PARAVIEW, TECPLOT, STL) TABULAR_FORMAT= CSV % Output file convergence history (w/o extension) CONV_FILENAME= history % Output file restart flow RESTART_FILENAME= restart_flow.dat % Output file restart adjoint RESTART_ADJ_FILENAME= restart_adj.dat % Output file flow (w/o extension) variables VOLUME_FILENAME= multizone_AIR_changed % Output file adjoint (w/o extension) variables VOLUME_ADJ_FILENAME= adjoint % Output objective function gradient (using continuous adjoint) GRAD_OBJFUNC_FILENAME= of_grad.dat % Output file surface flow coefficient (w/o extension) SURFACE_FILENAME= surface_flow % Output file surface adjoint coefficient (w/o extension) SURFACE_ADJ_FILENAME= surface_adjoint % Writing solution file frequency OUTPUT_WRT_FREQ= 1000 Thank you in advance, Nicola |
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Tags |
carbon dioxide, nicfd, pengrobinson |
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