Diffusion Analysis Setting [Wall Face]

Analysis condition for the diffusion analysis is set.

Type of Diffusion Boundary Condition

Notes

Zero Diffusion Flux

Specifies for the case where the diffusing material is not lost or gained. (Diffusion Flux of 0)

Value of Diffusing Medium

Sets the value of diffusion quantity of the wall face.

How to Specify

Notes

Use ambient value

Uses the ambient value set in [Diffusion Analysis Setting].

Direct Entry

Sets the value of diffusion quantity.

*Time dependency setting with the weight function is allowed for the transient analysis.

Select Time Dependency and click Weight Function. [Time-Weight] table will appear.
Fill in the table to set the change over time.

Flux

Sets the diffusion flux given to the fluid from the wall face.

Transfer Coefficient

Specifies diffusion transfer between the boundary and the outer environment.

Diffusion flux by diffusion transfer is calculated from φ for flux at the boundary surface, φamb for ambient value, and h for transfer coefficient.

The diffusion flux from the boundary to the environment is

h(φ-φamb).

Used when diffusion transfer to the outer environment beyond the solid wall is taken into account.

Ambient Value Setting

How to Specify

Notes

Use ambient value

Uses the ambient value set in [Diffusion Analysis Setting].

Direct Entry

Sets the ambient value.

For transient analysis, the change of ambient temperature over time can be set by selecting Time Dependency.

By clicking Weight Function, the [Time-Weight] table will appear.