Learning Forum

[kartikeya parmar]

A porous flow in a lid driven cavity is to be analyzed for different darcy number. My question is how o put darcy number in ansys. The different paper says flow is analyzed for different darcy number from 0.001 to 0.1. The darcy number is Da=K/D^2 where K=permeability so can i change the permeability value for different darcy number. and does permeability is equal to inverse of viscous resistance in ansys.

[Federico Alzamora Previtali]

Fluent defines the Viscous resistance as 1/alpha, where alpha is the permeability [m^2]. You can define the viscous resistance of your porous medium in the cell zone conditions dialog box.

7.2.3.8 User Inputs for Porous Media (ansys.com)

[kartikeya parmar]

i am trying to produce result of a paper in which they analyzed flow for different darcy number but i dont know how to put different darcy number in ansys. also the nusselt number is not matching neither the streamline. have yoy previously worked on porous media in ansys?

The paper which i am following:

Analysis of momentum and energy transfer in a lid-driven

cavity ®lled with a porous medium

[Federico Alzamora Previtali]

I do not have access to this paper. In order for us to provide specific guidelines, you will need to share information on your setup. There can be several reasons for Nu not matching.

Regarding varying Darcy number, you will need to vary the Viscous resistance of your porous region to match the desired Da.

[kartikeya parmar]

thank you for your time

actually for darcy number 0.1 when i change richardson number from 0.01 to 5 the value of nusselt number changes in paper but my value does not change. i am using grasoff number 10^4 and the value of fluid properties are density =998 dynamic viscosity 0.000855 beta value=0.000332 and cp=4180. for the porous material i use copper. The value of viscous resistance i have taken 10,100,1000 and 11884. the value of porosity is 0.9. also if you see in my results the value of streamlines are also not matching with the darcy number 0.1 and richardson number 1. it makes me feel something is wrong in my analysis.

[kartikeya parmar]

can dynamic meshing be the problem due to which i am not getting result.

the flow is steady can anyone suggest