Home / Examples / Fluid Analysis [Bernoulli] / Example 11: Humidifier

Example 11: Humidifier

General

• Concentration of vapor coming from the humidifier is analyzed.
   

• Steady-state mode of the fluid analysis and transient mode of the diffusion analysis are applied.
   

• Unless specified in the list below, the default conditions are applied.

 

• Obtain this session's project file. (Right-click and choose 'Save link as')




• Results will vary depending on Femtet version and the PC environment.

 

Analysis Space

Item	Settings
Analysis Space	3D
Model Unit	m

 

Analysis Conditions

Item	Tab	Settings
Solver	Solver Selection	Fluid analysis [Bernoulli]
Analysis Type	Fluid Analysis	Steady-state Analysis
Timestep	Transient Analysis	Timestep: Specify   Number Number of Calculation Steps Output Interval Timestep [s] 1 10 1 1
Diffusion Analysis	Fluid Analysis	Select Diffusion Analysis
Diffusion Analysis Setting	Fluid Analysis	Analysis type: Transient analysis   Type and unit of diffusion quantity: Mole fraction [%] Ambient Value: 30[%] Initial Value: 30 [%]
Meshing Setup	Mesh	General Mesh Size: 0.05 [m]

 

Model

The air domain is shown as below. The air and the saturated vapor(Mole fraction: 100%) flow in from the tip of the humidifier (Inlet).

Body Attributes and Materials

Body Number/Type	Body Attribute Name	Material Name
6/Solid	Air	000_Air *

* Available from the material DB

Boundary Condition

Boundary Condition Name/Topology	Tab	Boundary Condition Type	Settings
Inlet/Face	Fluid	Inlet	Specify flow velocity 2 [m/s]   Diffusion Analysis Setting   Value of diffusion quantity: Direct entry 100 [%]
Outlet/Face	Fluid	Inlet/Outlet

 

 

Results

The flow velocity and the streamlines at the last step (10 [s]) are shown in the figure below.

 

 

Isosurface contours of the mole fraction at times 2, 5, and 10 [s] are shown below.

You can observe the isosurface of humidity of 35% is spreading upward over time.

 

	Isosurface Contour
Time: 2 [s]
Time: 5 [s]
Time: 10 [s]