12.1.4. Geometry and Discretization

12.1.4.1. COORDINATES

Data Type: CHARACTER

Coordinate system used in the simulation.

Table 12.24 Valid Values

Name

Default?

Description

Cartesian

Cartesian coordinates.

cylindrical

Cylindrical coordinates.

12.1.4.2. IMAX

Data Type: INTEGER

Number of cells in the x (r) direction.

12.1.4.3. DX(CELL)

Data Type: DOUBLE PRECISION

  • \(0 \le Cell \le 5000\)

Cell sizes in the x (r) direction. Enter values from DX(0) to DX(IMAX-1).

  • Use uniform mesh size with higher-order discretization methods.

  • DX should be kept uniform in cylindrical coordinates for strict momentum conservation.

12.1.4.4. XMIN

Data Type: DOUBLE PRECISION

The inner radius in the simulation of an annular cylindrical region.

12.1.4.5. XLENGTH

Data Type: DOUBLE PRECISION

Simulation domain length in the x (r) direction.

12.1.4.6. X_MIN

Data Type: DOUBLE PRECISION

Simulation domain lower bound in the x-direction.

12.1.4.7. X_MAX

Data Type: DOUBLE PRECISION

Simulation domain upper bound in the x-direction.

12.1.4.8. JMAX

Data Type: INTEGER

Number of cells in the y-direction.

12.1.4.9. DY(CELL)

Data Type: DOUBLE PRECISION

  • \(0 \le Cell \le 5000\)

Cell sizes in the y-direction. Enter values from DY(0) to DY(JMAX-1). Use uniform mesh size with second-order discretization methods.

12.1.4.10. YLENGTH

Data Type: DOUBLE PRECISION

Simulation domain length in the y-direction.

12.1.4.11. Y_MIN

Data Type: DOUBLE PRECISION

Simulation domain lower bound in the y-direction.

12.1.4.12. Y_MAX

Data Type: DOUBLE PRECISION

Simulation domain upper bound in the y-direction.

12.1.4.13. NO_K

Data Type: LOGICAL

Flag to disable the third dimension (i.e., 2D simulation).

  • Z axis in Cartesian coordinate system

  • Theta in cylindrical coordinate system

Table 12.25 Valid Values

Name

Default?

Description

.FALSE.

3D simulation.

.TRUE.

2D simulation.

12.1.4.14. KMAX

Data Type: INTEGER

Number of cells in the z-direction.

12.1.4.15. DZ(CELL)

Data Type: DOUBLE PRECISION

  • \(0 \le Cell \le 5000\)

Cell sizes in the z (theta) direction. Enter values from DZ(0) to DZ(KMAX-1). Use uniform mesh size with second-order discretization methods.

12.1.4.16. Z_MIN

Data Type: DOUBLE PRECISION

Simulation domain lower bound in the z-direction.

12.1.4.17. Z_MAX

Data Type: DOUBLE PRECISION

Simulation domain upper bound in the z-direction.

12.1.4.18. ZLENGTH

Data Type: DOUBLE PRECISION

Simulation domain length in the z (theta) direction.

12.1.4.19. CYCLIC_X

Data Type: LOGICAL

Flag for making the x-direction cyclic without pressure drop. No other boundary conditions for the x-direction should be specified.

Table 12.26 Valid Values

Name

Default?

Description

.FALSE.

No cyclic condition at x-boundary.

.TRUE.

Cyclic condition at x-boundary.

12.1.4.20. CYCLIC_X_PD

Data Type: LOGICAL

Flag for making the x-direction cyclic with pressure drop. If the keyword FLUX_G is given a value, this becomes a cyclic boundary condition with specified mass flux. No other boundary conditions for the x-direction should be specified.

Table 12.27 Valid Values

Name

Default?

Description

.FALSE.

No cyclic condition at x-boundary.

.TRUE.

Cyclic condition with pressure drop at x-boundary.

12.1.4.21. DELP_X

Data Type: DOUBLE PRECISION

Fluid pressure drop across XLENGTH when a cyclic boundary condition with pressure drop is imposed in the x-direction.

12.1.4.22. CYCLIC_Y

Data Type: LOGICAL

Flag for making the y-direction cyclic without pressure drop. No other boundary conditions for the y-direction should be specified.

Table 12.28 Valid Values

Name

Default?

Description

.FALSE.

No cyclic condition at y-boundary.

.TRUE.

Cyclic condition at x-boundary.

12.1.4.23. CYCLIC_Y_PD

Data Type: LOGICAL

Flag for making the y-direction cyclic with pressure drop. If the keyword FLUX_G is given a value this becomes a cyclic boundary condition with specified mass flux. No other boundary conditions for the y-direction should be specified.

Table 12.29 Valid Values

Name

Default?

Description

.FALSE.

No cyclic condition at y-boundary.

.TRUE.

Cyclic condition with pressure drop at y-boundary.

12.1.4.24. DELP_Y

Data Type: DOUBLE PRECISION

Fluid pressure drop across YLENGTH when a cyclic boundary condition with pressure drop is imposed in the y-direction.

12.1.4.25. CYCLIC_Z

Data Type: LOGICAL

Flag for making the z-direction cyclic without pressure drop. No other boundary conditions for the z-direction should be specified.

Table 12.30 Valid Values

Name

Default?

Description

.FALSE.

No cyclic condition at z-boundary.

.TRUE.

Cyclic condition at z-boundary.

12.1.4.26. CYCLIC_Z_PD

Data Type: LOGICAL

Flag for making the z-direction cyclic with pressure drop. If the keyword FLUX_G is given a value this becomes a cyclic boundary condition with specified mass flux. No other boundary conditions for the z-direction should be specified.

Table 12.31 Valid Values

Name

Default?

Description

.FALSE.

No cyclic condition at z-boundary.

.TRUE.

Cyclic condition with pressure drop at z-boundary.

12.1.4.27. DELP_Z

Data Type: DOUBLE PRECISION

Fluid pressure drop across ZLENGTH when a cyclic boundary condition with pressure drop is imposed in the z-direction.

12.1.4.28. SHEAR

Data Type: LOGICAL

Imposes a mean shear on the flow field as a linear function of the x coordinate. This feature should only be used when CYCLIC_X is .TRUE. and the keyword V_SH is set.

12.1.4.29. V_SH

Data Type: DOUBLE PRECISION

Specifies the mean y velocity component at the eastern boundary of the domain (V_SH), and the mean Y velocity (-V_SH) at the western boundary of the domain.

12.1.4.30. FLUX_G

Data Type: DOUBLE PRECISION

If a value is specified, then the domain-averaged gas flux is held constant at that value in simulations over a periodic domain. A pair of boundaries specified as periodic with fixed pressure drop is then treated as periodic with fixed mass flux. Even for this case a pressure drop must also be specified, which is used as the initial guess in the simulations.

12.1.4.31. CYLINDRICAL_2D

Data Type: LOGICAL

Applies the 2.5D model for cylindrical column by combining 2D assumption and axi-symmetric assumption. Li et al. (2015). A 2.5D computational method to simulate cylindrical fluidized beds, Chemical Engineering Science, 123:236-246.

12.1.4.32. I_CYL_NUM

Data Type: INTEGER

Parameter to control the plate half width and the wedge radius in the 2.5D cylindrical model. This value should be less than half the grid cells in the radial direction (IMAX/2). [1]

12.1.4.33. I_CYL_TRANSITION

Data Type: INTEGER

Parameter to smooth the transition from cylindrical to 2D in the 2.5D cylindrical model. [2]

Table 12.32 Valid Values

Name

Default?

Description

2

Two cell smoothing transition.

1

One cell smoothing transition.

0

No smoothing.

12.1.4.34. CPX(CTRL)

Data Type: DOUBLE PRECISION

  • \(0 \le CTRL \le MAX{\_}CP\)

Location of control points in x-direction.

12.1.4.35. NCX(CTRL)

Data Type: INTEGER

  • \(1 \le CTRL \le MAX{\_}CP\)

Number of cells within a segment (x-direction).

12.1.4.36. ERX(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Expansion ratio (last DX/first DX) in a segment (x-direction).

12.1.4.37. FIRST_DX(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Value of first DX in a segment (x-direction). A negative

value will copy DX from previous segment (if available).

12.1.4.38. LAST_DX(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Value of last DX in a segment (x-direction). A

negative value will copy DX from next segment (if available).

12.1.4.39. CPY(CTRL)

Data Type: DOUBLE PRECISION

  • \(0 \le CTRL \le MAX{\_}CP\)

Location of control points in y-direction.

12.1.4.40. NCY(CTRL)

Data Type: INTEGER

  • \(1 \le CTRL \le MAX{\_}CP\)

Number of cells within a segment (y-direction).

12.1.4.41. ERY(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Expansion ratio (last DY/first DY) in a segment (y-direction).

12.1.4.42. FIRST_DY(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Value of first DY in a segment (y-direction). A negative value will copy DY from previous segment (if available).

12.1.4.43. LAST_DY(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Value of last DY in a segment (y-direction). A negative value will copy DY from next segment (if available).

12.1.4.44. CPZ(CTRL)

Data Type: DOUBLE PRECISION

  • \(0 \le CTRL \le MAX{\_}CP\)

Location of control points in z-direction.

12.1.4.45. NCZ(CTRL)

Data Type: INTEGER

  • \(1 \le CTRL \le MAX{\_}CP\)

Number of cells within a segment (z-direction).

12.1.4.46. ERZ(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Expansion ratio (last DZ/first DZ) in a segment (z-direction).

12.1.4.47. FIRST_DZ(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Value of first DZ in a segment (z-direction). A negative value will copy DZ from previous segment (if available).

12.1.4.48. LAST_DZ(CTRL)

Data Type: DOUBLE PRECISION

  • \(1 \le CTRL \le MAX{\_}CP\)

Value of last DZ in a segment (z-direction). A negative value will copy DZ from next segment (if available).