Setting the Boundary Conditions

The coal particles transport air enters the computational domain through a velocity inlet boundary at a constant velocity of 23 m/s. The combustion air flows in as a radial velocity profile with a swirl around the axis. You specify this velocity profile as a radial table with respect to a local cylindrical coordinate system.

At the individual walls of the combustor, you specify constant temperatures together with radiation properties.

To set the boundary conditions:

Edit the Regions > coalCombustor > Boundaries > COALANDTRANSPORTAIRINLET node and set the following properties:


Node	Property	Setting
Physics Conditions
Turbulence Specification	Method	Intensity + Length Scale
Physics Values
Radiation Temperature	Value	343.15 K
Species Mass Fraction	Value	N2: 0.767 O2: 0.233
Static Temperature	Value	343.15 K
Surface Material	Surface Material	Inlet Ducts
Turbulence Intensity	Value	0.1
Turbulent Length Scale	Value	6.5 mm
Velocity Magnitude	Value	23.0 m/s

Edit the COMBUSTIONAIRINLET node and set the following properties:


Node	Property	Setting
Physics Conditions
Turbulence Specification	Method	Intensity + Length Scale
Velocity Specification	Method	Components
Physics Values
Radiation Temperature	Value	573.15 K
Species Mass Fraction	Value	N2: 0.767 O2: 0.233
Surface Material	Surface Material	Inlet Ducts
Turbulence Intensity	Value	0.2
Turbulent Length Scale	Value	2.35 cm
Velocity	Method	Table (r)
Velocity	Coordinate System	Laboratory -> Cylindrical 1
Table (r)	Table	AirInletProfile
	Table: X-Data	V-radial
	Table: Y-Data	V-theta
	Table: Z-Data	V-z

Select the OUTLET node and set the following properties:


Node	Property	Setting
Physics Values
Radiation Temperature	Value	300 K
Surface Material	Surface Material	Furnace

Set the thermal specifications at the coal combustor walls.

Expand the Regions > coalCombustor > Boundaries node and multi-edit the following boundary nodes:
- BURNERQUARLWALL
- CHIMNEYWALL
- COALGUNFRONTWALL01
- COALGUNFRONTWALL02
- COOLINGLOOPS
- FURNACEBACKWALL
- FURNACECYLINDERWALL
- FURNACEFRONTWALL
- INLETDUCTWALL-INNER
- INLETDUCTWALLS-OUTER
In the Multiple Objects dialog, select the Physics Conditions > Thermal Specification node and set Condition to Temperature, then click Close.

Select the BURNERQUARLWALL node and set the following properties:


Node	Property	Setting
Physics Values
Static Temperature	Value	1273.0 K
Surface Material	Surface Material	Inlet Ducts

Select the CHIMNEYWALL node and set the following properties:


Node	Property	Setting
Physics Values
Static Temperature	Value	1300.0 K
Surface Material	Surface Material	Furnace

Multi-select the COALGUNFRONTWALL01 and the COALGUNFRONTWALL02 nodes, and set the following properties:


Node	Property	Setting
Physics Values
Static Temperature	Value	800.0 K
Surface Material	Surface Material	Inlet Ducts

Select the COOLINGLOOPS node and set the following properties:


Node	Property	Setting
Physics Values
Static Temperature	Value	1000.0 K
Surface Material	Surface Material	Cooling Loops

Select the FURNACEBACKWALL node and set the following properties:


Node	Property	Setting
Physics Values
Static Temperature	Value	1300.0 K
Surface Material	Surface Material	Furnace

Select the FURNACECYLINDERWALL and the FURNACEFRONTWALL nodes and set the following properties:


Node	Property	Setting
Physics Values
Static Temperature	Value	1400.0 K
Surface Material	Surface Material	Furnace

Select the INLETDUCTWALL-INNER node and set the following properties:


Node	Property	Setting
Physics Values
Surface Material	Surface Material	Inlet Ducts

Select the INLETDUCTWALLS-OUTER node and set the following properties:


Node	Property	Setting
Physics Values
Static Temperature	Value	573.0 K
Surface Material	Surface Material	Inlet Ducts

Save the simulation.