Case Creator Guide

Case Creator Guide

Quick reference for building MFC cases: working examples, compatibility rules, and configuration requirements.

Auto-generated from case_validator.py and examples/.

🧩 Case Design Playbook

Learn by example: The cases below are curated from MFC's examples/ directory and are validated, working configurations. Use them as blueprints for building your own simulations.

🟢 Beginner Examples

2D Shock-Bubble Interaction 🟢 Beginner · 2D_shockbubble

Two-fluid shock-interface benchmark. Classic validation case for compressible multiphase flows.

Tags: 2D · Multiphase · Shock

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 2
• Dimensionality: 2D

Numerical Methods:

• Reconstruction: WENO-5
• Riemann solver: HLLC (riemann_solver = 2)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)
• Riemann Solvers

🟡 Intermediate Examples

1D Bubble Screen 🟡 Intermediate · 1D_bubblescreen

Euler-Euler ensemble-averaged bubble dynamics through shock wave.

Tags: 1D · Bubbles · Euler-Euler

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 1
• Dimensionality: 1D
• Active features: Euler-Euler bubbles, Acoustic sources

Numerical Methods:

• Reconstruction: WENO-5
• Riemann solver: HLLC (riemann_solver = 2)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)
• Riemann Solvers
• Bubble Models

2D Lagrangian Bubble Screen 🟡 Intermediate · 2D_lagrange_bubblescreen

Individual bubble tracking with Euler-Lagrange method.

Tags: 2D · Bubbles · Euler-Lagrange

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 2
• Dimensionality: 2D
• Active features: Euler-Lagrange bubbles, Viscous, Acoustic sources

Numerical Methods:

• Reconstruction: WENO-5
• Riemann solver: HLLC (riemann_solver = 2)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)
• Riemann Solvers
• Bubble Models
• Viscosity

2D Orszag-Tang MHD Vortex 🟡 Intermediate · 2D_orszag_tang

Magnetohydrodynamics test problem with complex vortex structures.

Tags: 2D · MHD

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 1
• Dimensionality: 2D
• Active features: MHD

Numerical Methods:

• Reconstruction: WENO-1
• Riemann solver: HLL (riemann_solver = 1)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)
• Riemann Solvers
• MHD

2D IBM Airfoil 🟡 Intermediate · 2D_ibm_airfoil

Immersed boundary method around a NACA airfoil geometry.

Tags: 2D · IBM · Geometry

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 2
• Dimensionality: 2D
• Active features: Immersed boundaries

Numerical Methods:

• Reconstruction: WENO-5
• Riemann solver: HLLC (riemann_solver = 2)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)
• Riemann Solvers
• Immersed Boundaries

2D Viscous Shock Tube 🟡 Intermediate · 2D_viscous_shock_tube

Shock tube with viscous effects and heat transfer.

Tags: 2D · Viscous · Shock

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 2
• Dimensionality: 2D
• Active features: Viscous

Numerical Methods:

• Reconstruction: WENO-3
• Riemann solver: HLL (riemann_solver = 1)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)
• Riemann Solvers
• Viscosity

🔴 Advanced Examples

2D Phase Change Bubble 🔴 Advanced · 2D_phasechange_bubble

Phase change and cavitation modeling with 6-equation model.

Tags: 2D · Phase-change · Cavitation

Physics Configuration:

• Model: 6-Equation (model_eqns = 3)
• Number of fluids: 3
• Dimensionality: 2D
• Coordinates: Cylindrical/Axisymmetric
• Active features: Phase change

Numerical Methods:

• Reconstruction: WENO-3
• Riemann solver: HLLC (riemann_solver = 2)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 3)
• Riemann Solvers

3D Taylor-Green Vortex 🔴 Advanced · 3D_TaylorGreenVortex

Classic 3D turbulence benchmark with viscous dissipation.

Tags: 3D · Viscous · Turbulence

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 1
• Dimensionality: 3D
• Active features: Viscous

Numerical Methods:

• Reconstruction: WENO-5
• Riemann solver: HLLC (riemann_solver = 2)
• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)
• Riemann Solvers
• Viscosity

2D IGR Triple Point 🔴 Advanced · 2D_IGR_triple_point

Triple point problem using Iterative Generalized Riemann solver.

Tags: 2D · IGR · Multiphase

Physics Configuration:

• Model: 5-Equation (model_eqns = 2)
• Number of fluids: 2
• Dimensionality: 2D
• Active features: IGR solver

Numerical Methods:

• Time stepping: RK3 (SSP)

Related Documentation:

• Model Equations (model_eqns = 2)

🚀 Common Configuration Patterns

Start with these proven combinations:

💧 Multiphase Flow (Bubbles)

'model_eqns': 2,              # 5-equation model
'num_fluids': 2,              # Two-phase
'bubbles_euler': 'T',         # Ensemble-averaged bubbles
'riemann_solver': 2,          # HLLC
'avg_state': 2,               # Arithmetic average

⚡ Magnetohydrodynamics (MHD)

'model_eqns': 2,              # 5-equation model
'num_fluids': 1,              # Single component
'mhd': 'T',                   # Enable MHD
'riemann_solver': 1,          # HLL (or 4 for HLLD)

🌡️ Phase Change

'model_eqns': 3,              # 6-equation model
'num_fluids': 2,              # Two-phase
'relax': 'T',                 # Phase change
'riemann_solver': 2,          # HLLC

💎 Elastic Materials

'model_eqns': 2,              # 5-equation model
'hypoelasticity': 'T',        # Elastic solids
'riemann_solver': 1,          # HLL

📊 Feature Compatibility

What works together:

Physics Models

Feature	Requirements	Notes
Magnetohydrodynamics (MHD)	—	✓ General use
Surface Tension Model	Specific model	✓ General use
Hypoelasticity	—	✓ General use
Hyperelasticity	—	✓ General use
Phase Change (Relaxation)	—	✓ General use
Viscosity	—	✓ General use
Acoustic Sources	—	✓ General use

Bubble Models

Feature	Requirements	Notes
Euler-Euler Bubble Model	—	⚠️ Not with: Euler-Lagrange Bubble Model
Euler-Lagrange Bubble Model	—	⚠️ Not with: Euler-Euler Bubble Model
Quadrature-Based Moment Method (QBMM)	—	✓ General use
Polydisperse Bubble Dynamics	—	✓ General use
adv_n	—	✓ General use

Numerics

Feature	Requirements	Notes
Riemann Solver	Specific model	✓ General use
WENO Order	—	✓ General use
MUSCL Order	—	✓ General use

Geometry

Feature	Requirements	Notes
Immersed Boundaries	—	✓ General use
Cylindrical Coordinates	—	✓ General use

🔢 Model Equations

Choose your governing equations:

Model 1: Gamma-law

• Use for: Single-fluid compressible flow
• Value: model_eqns = 1
• Note: Cannot use num_fluids, bubbles, or certain WENO variants

Model 2: 5-Equation

• Use for: Multiphase, bubbles, elastic materials, MHD
• Value: model_eqns = 2
• Requirements: Set num_fluids
• Note: Compatible with most physics models

Model 3: 6-Equation

• Use for: Phase change, cavitation
• Value: model_eqns = 3
• Requirements: riemann_solver = 2 (HLLC), avg_state = 2 (arithmetic), wave_speeds = 1 (direct)
• Note: Not compatible with bubbles or 3D cylindrical

Model 4: 4-Equation

• Use for: Single-component flows with bubbles
• Value: model_eqns = 4
• Requirements: Set rhoref, Set pref, num_fluids = 1 (1)

⚙️ Riemann Solvers

Solver	riemann_solver	Best For	Requirements
HLL	1	MHD, elastic materials	—
HLLC	2	Bubbles, phase change, multiphase	avg_state=2 for bubbles
Exact	3	High accuracy (expensive)	—
HLLD	4	MHD (advanced)	MHD only, no relativity
Lax-Friedrichs	5	Robust fallback	Not with cylindrical+viscous

💧 Bubble Models

Euler-Euler (bubbles_euler)

Requirements:

• model_eqns = 2 (5-Equation) or 4 (4-Equation)
• riemann_solver = 2 (HLLC)
• avg_state = 2 (arithmetic)
• Recommended to also set: nb, polytropic

Extensions:

• polydisperse = T: Multiple bubble sizes (requires nb, poly_sigma), odd nb > 1
• qbmm = T: Quadrature method (recommends bubbles_euler), requires nnode = 4
• adv_n = T: Number density advection (requires num_fluids = 1)

Euler-Lagrange (bubbles_lagrange)

Requirements:

• n > 0 (2D or 3D only)
• file_per_process = F
• Not compatible with model_eqns = 3

Note: Tracks individual bubbles

📖 Quick Parameter Reference

Key parameters and their constraints:

R0ref (R0ref)

Schema constraints:

• Min: 0

Acoustic Sources (acoustic_source)

Dependencies:

• When enabled, requires: num_source

avg_state (avg_state)

Schema constraints:

• Choices: 1 = Roe, 2 = arithmetic

Requirements (errors):

• avg_state must be set if riemann_solver != 3,5
• 6-equation model (model_eqns = 3) requires avg_state = 2
• Bubble modeling requires arithmetic average (avg_state = 2)

Valid values (errors):

• avg_state must be 1 or 2

bf_x (bf_x)

Dependencies:

• When enabled, requires: k_x, w_x, p_x, g_x

Requirements (errors):

• k_x must be specified if bf_x is true
• w_x must be specified if bf_x is true
• p_x must be specified if bf_x is true

bf_y (bf_y)

Dependencies:

• When enabled, requires: k_y, w_y, p_y, g_y

Requirements (errors):

• k_y must be specified if bf_y is true
• w_y must be specified if bf_y is true
• p_y must be specified if bf_y is true

bf_z (bf_z)

Dependencies:

• When enabled, requires: k_z, w_z, p_z, g_z

Requirements (errors):

• k_z must be specified if bf_z is true
• w_z must be specified if bf_z is true
• p_z must be specified if bf_z is true

bubble_model (bubble_model)

Schema constraints:

• Choices: 1 = Gilmore, 2 = Keller-Miksis, 3 = Rayleigh-Plesset

Incompatibilities (errors):

• The 5-equation bubbly flow model does not support bubble_model = 1 (Gilmore)

Euler-Euler Bubble Model (bubbles_euler)

Dependencies:

• When enabled, requires model_eqns = 2 (5-Equation) or 4 (4-Equation), riemann_solver = 2 (HLLC), avg_state = 2 (arithmetic)
• When enabled, recommends: nb, polytropic

Requirements (errors):

• Polydisperse bubble modeling requires the bubbles_euler flag to be set
• QBMM requires the bubbles_euler flag to be set
• adv_n requires bubbles_euler to be enabled

Incompatibilities (errors):

• Activate only one of the bubble subgrid models (bubbles_euler or bubbles_lagrange)
• alt_soundspeed is not compatible with bubbles_euler

Valid values (errors):

• patch_icpp(istr)r0 must be positive (got r0)

cfl_adap_dt (cfl_adap_dt)

Dependencies:

• When enabled, recommends: cfl_target

Requirements (errors):

• dt must be set when using fixed time stepping (t_step_start/t_step_stop)

Valid values (errors):

• t_stop must be positive
• t_save must be positive

cfl_dt (cfl_dt)

Dependencies:

• When enabled, recommends: cfl_target

Requirements (errors):

• dt must be set when using fixed time stepping (t_step_start/t_step_stop)

Valid values (errors):

• t_stop must be positive
• t_save must be positive

cfl_max (cfl_max)

Schema constraints:

• Min: 0

cfl_target (cfl_target)

Schema constraints:

• Min: 0

chemistry (chemistry)

Dependencies:

• When enabled, requires: cantera_file

dt (dt)

Schema constraints:

• Min: 0

Valid values (errors):

• dt must be positive

format (format)

Schema constraints:

• Choices: 1 = Silo, 2 = binary

Requirements (errors):

• output_partial_domain requires format = 2

Valid values (errors):

• format must be 1 or 2

Immersed Boundaries (ib)

Dependencies:

• When enabled, requires: num_ibs

Requirements (errors):

• Immersed Boundaries do not work in 1D (requires n > 0)

Incompatibilities (errors):

• output_partial_domain is incompatible with certain output flags

Valid values (errors):

• num_ibs must be between 1 and num_patches_max (10)

integral_wrt (integral_wrt)

Dependencies:

• When enabled, requires: fd_order

Requirements (errors):

• fd_order must be specified for integral_wrt
• integral_wrt requires bubbles_euler to be enabled

m (m)

Schema constraints:

• Min: 0

Requirements (errors):

• x_domainbeg must be set when m > 0
• x_domainend must be set when m > 0
• down sample requires m divisible by 3

Valid values (errors):

• m must be positive
• m must be at least igr_order - 1 (= igr_order - 1)

Model Equations (model_eqns)

Schema constraints:

• Choices: 1 = Gamma-law, 2 = 5-Equation, 3 = 6-Equation, 4 = 4-Equation

Dependencies:

• When = 2, requires: num_fluids
• When = 3, requires riemann_solver = 2 (HLLC), avg_state = 2 (arithmetic), wave_speeds = 1 (direct)
• When = 4, requires: rhoref, pref
• When = 4, requires num_fluids = 1 (1)

Requirements (errors):

• 5-equation model (model_eqns = 2) requires num_fluids to be set
• 6-equation model (model_eqns = 3) requires num_fluids to be set
• 4-equation model (model_eqns = 4) requires num_fluids to be set

Incompatibilities (errors):

• num_fluids is not supported for model_eqns = 1
• model_eqns = 1 does not support mpp_lim
• 6-equation model (model_eqns = 3) does not support cylindrical coordinates (cyl_coord = T and p != 0)

Valid values (errors):

• model_eqns must be 1, 2, 3, or 4

muscl_lim (muscl_lim)

Schema constraints:

• Choices: 1 = minmod, 2 = MC, 3 = Van Albada, 4 = Van Leer, 5 = SUPERBEE

Valid values (errors):

• muscl_lim must be 1, 2, 3, 4, or 5

MUSCL Order (muscl_order)

Schema constraints:

• Choices: 1 = 1st order, 2 = 2nd order

Valid values (errors):

• muscl_order must be 1 or 2
• m must be at least muscl_order - 1 (= muscl_order - 1)

n (n)

Schema constraints:

• Min: 0

Requirements (errors):

• Immersed Boundaries do not work in 1D (requires n > 0)
• down sample requires n divisible by 3
• stretch_y requires n > 0

Incompatibilities (errors):

• Bx0 must not be set in 2D/3D MHD simulations
• Hyperbolic cleaning is not supported for 1D simulations

Valid values (errors):

• n must be non-negative
• n must be at least igr_order - 1 (= igr_order - 1)

nb (nb)

Schema constraints:

• Min: 1

Requirements (errors):

• The Ensemble-Averaged Bubble Model requires nb >= 1
• Polydisperse bubble dynamics requires nb > 1

Valid values (errors):

• nb must be odd for polydisperse bubbles

Number of Fluids (num_fluids)

Schema constraints:

• Min: 1
• Max: 10

Requirements (errors):

• 5-equation model (model_eqns = 2) requires num_fluids to be set
• 6-equation model (model_eqns = 3) requires num_fluids to be set
• 4-equation model (model_eqns = 4) requires num_fluids to be set

Incompatibilities (errors):

• num_fluids is not supported for model_eqns = 1
• num_fluids = 1 does not support mpp_lim

Valid values (errors):

• num_fluids must be positive
• perturb_flow_fluid must be between 0 and num_fluids

num_ibs (num_ibs)

Schema constraints:

• Min: 0
• Max: 10

Valid values (errors):

• num_ibs must be between 1 and num_patches_max (10)

num_integrals (num_integrals)

Schema constraints:

• Min: 1

num_patches (num_patches)

Schema constraints:

• Min: 0
• Max: 10

Valid values (errors):

• num_patches must be non-negative
• num_patches must be positive for the non-restart case

num_probes (num_probes)

Schema constraints:

• Min: 1

num_source (num_source)

Schema constraints:

• Min: 1

Requirements (errors):

• num_source must be specified for acoustic_source

Valid values (errors):

• num_source must be non-negative

p (p)

Schema constraints:

• Min: 0

Requirements (errors):

• down sample requires 3D (p > 0)
• down sample requires p divisible by 3
• stretch_z requires p > 0

Incompatibilities (errors):

• 6-equation model (model_eqns = 3) does not support cylindrical coordinates (cyl_coord = T and p != 0)

Valid values (errors):

• p must be non-negative
• p must be odd for cylindrical coordinates

Polydisperse Bubble Dynamics (polydisperse)

Dependencies:

• When enabled, requires: nb, poly_sigma

Requirements (errors):

• Polydisperse bubble dynamics requires nb > 1
• Polydisperse bubble modeling requires the bubbles_euler flag to be set
• Polydisperse bubble modeling requires poly_sigma to be set

Valid values (errors):

• nb must be odd for polydisperse bubbles
• poly_sigma must be positive

precision (precision)

Schema constraints:

• Choices: 1 = single, 2 = double

Requirements (errors):

• output_partial_domain requires precision = 2

Valid values (errors):

• precision must be 1 or 2

probe_wrt (probe_wrt)

Dependencies:

• When enabled, requires: num_probes, fd_order

Requirements (errors):

• fd_order must be specified for probe_wrt

Quadrature-Based Moment Method (QBMM) (qbmm)

Dependencies:

• When enabled, recommends: bubbles_euler

Requirements (errors):

• QBMM requires the bubbles_euler flag to be set
• QBMM requires nnode = 4

Incompatibilities (errors):

• adv_n is not compatible with qbmm
• adap_dt is not compatible with qbmm

recon_type (recon_type)

Schema constraints:

• Choices: 1 = WENO, 2 = MUSCL

Dependencies:

• When = 2, recommends: muscl_order, muscl_lim

Requirements (errors):

• int_comp (THINC interface compression) requires recon_type = 2 (MUSCL)

relativity (relativity)

Dependencies:

• When enabled, requires: mhd

Requirements (errors):

• relativity requires mhd to be enabled

Incompatibilities (errors):

• HLLD is not available for RMHD (relativity)

Riemann Solver (riemann_solver)

Schema constraints:

• Choices: 1 = HLL, 2 = HLLC, 3 = Exact, 4 = HLLD, 5 = Lax-Friedrichs

Requirements (errors):

• hypoelasticity requires HLL Riemann solver (riemann_solver = 1)
• 6-equation model (model_eqns = 3) requires riemann_solver = 2 (HLLC)
• wave_speeds must be set if riemann_solver != 3,5

Incompatibilities (errors):

• Exact Riemann (riemann_solver = 3) does not support wave_speeds
• HLLD is not available for RMHD (relativity)

Valid values (errors):

• riemann_solver must be 1, 2, 3, 4 or 5

schlieren_wrt (schlieren_wrt)

Dependencies:

• When enabled, requires: fd_order

Requirements (errors):

• schlieren_wrt requires n > 0 (at least 2D)
• fd_order must be set for schlieren_wrt

Incompatibilities (errors):

• output_partial_domain is incompatible with certain output flags

sigma (sigma)

Schema constraints:

• Min: 0

Requirements (errors):

• sigma must be set if surface_tension is enabled

Valid values (errors):

• sigma must be greater than or equal to zero

stretch_x (stretch_x)

Dependencies:

• When enabled, requires: a_x, x_a, x_b

Requirements (errors):

• a_x must be set with stretch_x enabled
• x_a must be set with stretch_x enabled
• x_b must be set with stretch_x enabled

Incompatibilities (errors):

• old_grid and stretch_x are incompatible

Valid values (errors):

• x_a must be less than x_b with stretch_x enabled

stretch_y (stretch_y)

Dependencies:

• When enabled, requires: a_y, y_a, y_b

Requirements (errors):

• a_y must be set with stretch_y enabled
• y_a must be set with stretch_y enabled
• y_b must be set with stretch_y enabled

Incompatibilities (errors):

• old_grid and stretch_y are incompatible

Valid values (errors):

• y_a must be less than y_b with stretch_y enabled

stretch_z (stretch_z)

Dependencies:

• When enabled, requires: a_z, z_a, z_b

Requirements (errors):

• a_z must be set with stretch_z enabled
• z_a must be set with stretch_z enabled
• z_b must be set with stretch_z enabled

Incompatibilities (errors):

• old_grid and stretch_z are incompatible
• stretch_z is not compatible with cylindrical coordinates

Valid values (errors):

• z_a must be less than z_b with stretch_z enabled

Surface Tension Model (surface_tension)

Dependencies:

• When enabled, requires: sigma

Requirements (errors):

• sigma must be set if surface_tension is enabled
• The surface tension model requires model_eqns = 2 or model_eqns = 3
• The surface tension model requires num_fluids = 2

Valid values (errors):

• sigma must be greater than or equal to zero

t_save (t_save)

Schema constraints:

• Min: 0

Valid values (errors):

• t_save must be positive
• t_save must be <= t_stop

t_step_print (t_step_print)

Schema constraints:

• Min: 1

t_step_save (t_step_save)

Schema constraints:

• Min: 1

Valid values (errors):

• t_step_save must be positive
• t_step_save must be <= (t_step_stop - t_step_start)

t_stop (t_stop)

Schema constraints:

• Min: 0

Valid values (errors):

• t_stop must be positive
• t_save must be <= t_stop

teno (teno)

Dependencies:

• When enabled, requires: teno_CT

Requirements (errors):

• teno requires teno_CT to be set. A typical value is 1e-6
• teno requires weno_order = 5 or 7

Valid values (errors):

• teno_CT must be positive. A typical value is 1e-6

time_stepper (time_stepper)

Schema constraints:

• Choices: 1 = RK1 (Forward Euler), 2 = RK2, 3 = RK3 (SSP)

Requirements (errors):

• adap_dt requires Runge-Kutta 3 (time_stepper = 3)

Valid values (errors):

• time_stepper must be 1, 2, or 3

Viscosity (viscous)

Dependencies:

• When enabled, recommends: fluid_pp(1)Re(1)

wave_speeds (wave_speeds)

Schema constraints:

• Choices: 1 = direct, 2 = pressure

Requirements (errors):

• wave_speeds must be set if riemann_solver != 3,5
• 6-equation model (model_eqns = 3) requires wave_speeds = 1

Incompatibilities (errors):

• Exact Riemann (riemann_solver = 3) does not support wave_speeds

Valid values (errors):

• wave_speeds must be 1 or 2

weno_eps (weno_eps)

Schema constraints:

• Min: 0

Requirements (errors):

• weno_order != 1 requires weno_eps to be set. A typical value is 1e-6

Valid values (errors):

• weno_eps must be positive. A typical value is 1e-6

WENO Order (weno_order)

Schema constraints:

• Choices: 0 = MUSCL mode, 1 = 1st order, 3 = WENO3, 5 = WENO5, 7 = WENO7

Requirements (errors):

• weno_order != 1 requires weno_eps to be set. A typical value is 1e-6
• wenoz at 7th order requires wenoz_q to be set (should be 2, 3, or 4)
• teno requires weno_order = 5 or 7

Incompatibilities (errors):

• mapped_weno is not compatible with weno_order = 1
• wenoz is not compatible with weno_order = 1
• weno_order = 1 without weno_avg does not support fluid_pp(i)Re(j)

Valid values (errors):

• weno_order must be 1, 3, 5, or 7
• m must be at least weno_order - 1 (= weno_order - 1)

⚠️ Physics Warnings

These checks are non-fatal — they print a yellow warning but do not abort the run. They catch common mistakes in initial conditions and EOS parameters.

Check	Stage	Description
Alpha-Rho Consistency	pre_process	patch_icpp(i): alpha(j) = 0 but alpha_rho(j) = alpha_rho (density in absent phase); patch_icpp(i): alpha(j) = alpha but alpha_rho(j) = 0 (present phase has zero density)
EOS Parameter Sanity	common, post_process, pre_process, simulation	fluid_pp(i)gamma = gamma implies physical gamma = physical_gamma (unusually high). MFC uses the transformed parameter Gamma = 1/(gamma-1); fluid_pp(i)gamma = gamma implies physical gamma = physical_gamma (very close to 1). Did you enter the physical gamma instead of 1/(gamma-1)?
Volume Fraction Sum	pre_process	patch_icpp(i): volume fractions sum to alpha_sum, expected 1.0

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💡 Tip: If you encounter a validation error, check the relevant section above or review case_validator.py for complete validation logic.

Page last updated: 2026-02-27