# 8.3.9. Initial Condition¶

Each initial condition (IC) is specified over a rectangular region (or pie-shaped for cylindrical coordinates) that corresponds to the scalar numerical grid. These are 3D regions: X_w X_e, Y_s Y_n, and Z_t Z_b. The region is defined by the constant coordinates of each of the six faces, which may be specified as the physical coordinates or the cell indices. The physical coordinates are easier to specify than the cell indices. If cell sizes are not small enough to resolve a region specified using physical coordinates, MFIX will indicate this problem with an error message.

In cylindrical coordinates, when the theta direction crosses the 0 value, split that region into two regions: e.g., Split a region spanning 1.9 pi to 0.1 pi as 1.9 pi to 2 pi and 0 to 0.1 pi.

Initial condition regions may overlap. When an overlap occurs, MFIX uses the conditions specified for the higher IC number.

## 8.3.9.1. IC_X_W(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

X coordinate of the west face.

## 8.3.9.2. IC_X_E(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

X coordinate of the east face.

## 8.3.9.3. IC_Y_S(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Y coordinate of the south face.

## 8.3.9.4. IC_Y_N(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Y coordinate of the north face.

## 8.3.9.5. IC_Z_B(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Z coordinate of the bottom face.

## 8.3.9.6. IC_Z_T(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Z coordinate of the top face.

## 8.3.9.7. IC_I_W(IC)¶

Data Type: INTEGER

• $$1 \le IC \le 500$$

I index of the west-most wall.

## 8.3.9.8. IC_I_E(IC)¶

Data Type: INTEGER

• $$1 \le IC \le 500$$

I index of the east-most wall.

## 8.3.9.9. IC_J_S(IC)¶

Data Type: INTEGER

• $$1 \le IC \le 500$$

J index of the south-most wall.

## 8.3.9.10. IC_J_N(IC)¶

Data Type: INTEGER

• $$1 \le IC \le 500$$

J index of the north-most wall.

## 8.3.9.11. IC_K_B(IC)¶

Data Type: INTEGER

• $$1 \le IC \le 500$$

K index of the bottom-most wall.

## 8.3.9.12. IC_K_T(IC)¶

Data Type: INTEGER

• $$1 \le IC \le 500$$

K index of the top-most wall.

## 8.3.9.13. IC_TYPE(IC)¶

Data Type: CHARACTER

• $$1 \le IC \le 500$$

Type of initial condition. Mainly used in restart runs to overwrite values read from the .RES file by specifying it as _PATCH_. The user needs to be careful when using the _PATCH_ option, since the values from the .RES file are overwritten and no error checking is done for the patched values.

## 8.3.9.14. IC_EP_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial void fraction in the IC region.

## 8.3.9.15. IC_P_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial gas pressure in the IC region. If this quantity is not specified, MFiX will set up a hydrostatic pressure profile, which varies only in the y-direction.

## 8.3.9.16. IC_P_STAR(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial solids pressure in the IC region. Usually, this value is specified as zero.

## 8.3.9.17. IC_L_SCALE(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Turbulence length scale in the IC region.

## 8.3.9.18. IC_ROP_S(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Initial bulk density (rop_s = ro_s x ep_s) of solids phase in the IC region. Users need to specify this IC only for polydisperse flow (MMAX > 1). Users must make sure that summation of ( IC_ROP_s(ic,m) / RO_s(m) ) over all solids phases is equal to ( 1.0 - IC_EP_g(ic)).

## 8.3.9.19. IC_EP_S(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Initial solids volume fraction of solids phase in the IC region. This may be specified in place of IC_ROP_s.

## 8.3.9.20. IC_T_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial gas phase temperature in the IC region.

## 8.3.9.21. IC_T_S(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Initial solids phase temperature in the IC region.

## 8.3.9.22. IC_THETA_M(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Initial solids phase granular temperature in the IC region.

## 8.3.9.23. IC_GAMA_RG(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Gas phase radiation coefficient in the IC region. Modify file rdtn2.inc to change the source term.

## 8.3.9.24. IC_T_RG(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Gas phase radiation temperature in the IC region.

## 8.3.9.25. IC_GAMA_RS(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Solids phase radiation coefficient in the IC region. Modify file energy_mod.f to change the source term.

## 8.3.9.26. IC_T_RS(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Solids phase radiation temperature in the IC region.

## 8.3.9.27. IC_U_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial x-component of gas velocity in the IC region.

## 8.3.9.28. IC_U_S(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Initial x-component of solids-phase velocity in the IC region.

## 8.3.9.29. IC_V_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial y-component of gas velocity in the IC region.

## 8.3.9.30. IC_V_S(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Initial y-component of solids-phase velocity in the IC region.

## 8.3.9.31. IC_W_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial z-component of gas velocity in the IC region.

## 8.3.9.32. IC_W_S(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Initial z-component of solids-phase velocity in the IC region.

## 8.3.9.33. IC_X_G(IC, SPECIES)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Species \le 100$$

Initial mass fraction of gas species.

## 8.3.9.34. IC_X_S(IC, PHASE, SPECIES)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

• $$1 \le Species \le 100$$

Initial mass fraction of solids species.

## 8.3.9.35. IC_SCALAR(IC, SCALAR EQ.)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Scalar Eq. \le 100$$

Initial value of Scalar n, assigned to scalar equation.

## 8.3.9.36. IC_K_TURB_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial value of K in K-Epsilon equation.

## 8.3.9.37. IC_E_TURB_G(IC)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

Initial value of Epsilon in K-Epsilon equation.

## 8.3.9.38. IC_DES_FIT_TO_REGION(IC)¶

Data Type: LOGICAL

• $$1 \le IC \le 500$$

Flag for inflating initial lattice distribution

to the entire IC region.

## 8.3.9.39. IC_PIC_CONST_STATWT(IC, PHASE)¶

Data Type: DOUBLE PRECISION

• $$1 \le IC \le 500$$

• $$1 \le Phase \le 10$$

Flag to specify the initial constant statistical

weight for computational particles/parcels. Actual number of parcels will be automatically computed.