[lchhung]

Dear colleagues,
I am just a beginner in CFD simulation using ANSYS CFX. I am looking for the exact original reference of the Resistance Loss Coefficient in the Loss Model adopted in the CFX program.
I have checked with the Ergun equation and the Forchheimer equation but those do not make any sense to me.
I would be grateful if you could please suggest any ideas.
Thank you,
lchhung

[Opaque]

It would be great if you write the equations you are comparing for those in the forum to help you. Porous media vocabulary varies depending your area of interest; therefore, it is easier to look at equations directly.

Keep in mind the software provides a general framework for the user (us) to implement the specifics of a model of interest. By comparing the equations, we can see how the can be matched.

Hope the above helps,

[lchhung]

Hi Opaque,
Thank you for writing me.

I have found the original equation.

The original reference is the work of Ergun (1952).

I downloaded the paper via:

https://www.scribd.com/doc/306554469...-Columns-Ergun

I write here for other guys, who might look for the same problem in the future.

Kind regards,
lchhung

Originally Posted by Opaque

It would be great if you write the equations you are comparing for those in the forum to help you. .......................,

[evcelica]

Pressure Drop per Unit Length = [(Viscosity / KPerm) * Velocity] + [Kloss * (Density/2) * Velocity^2]

Where KPerm is the permeability and Kloss is the quadratic loss coefficient.

The linear component of this source represents viscous losses and the quadratic term represents inertial losses.

[Goenitz]

Originally Posted by evcelica

Pressure Drop per Unit Length = [(Viscosity / KPerm) * Velocity] + [Kloss * (Density/2) * Velocity^2]

Where KPerm is the permeability and Kloss is the quadratic loss coefficient.

The linear component of this source represents viscous losses and the quadratic term represents inertial losses.

In cfx resistance loss coefficient has units (1/m) I don't think inertial loss coefficient has any...

[Goenitz]

Originally Posted by evcelica

Pressure Drop per Unit Length = [(Viscosity / KPerm) * Velocity] + [Kloss * (Density/2) * Velocity^2]

Where KPerm is the permeability and Kloss is the quadratic loss coefficient.

The linear component of this source represents viscous losses and the quadratic term represents inertial losses.

Hi

What do you think density will be? of fluid mixture or fluid mixture+foam density?

[Opaque]

Based on Ergun's reference, as you pointed out:

The equation has been examined from the point of view of its dependence upon flow rate, properties of the fluids, and fractional void volume,orientation, size, shape, and surface of the granular solids.

It can only be the fluid density.