[nalamyogesh]

Hello All,

I was trying to compute porous coefficients and I have a negative value for my viscous coefficient. Is it possible to have negative values or what should be done in that case?

Thanks !!!

[fluid23]

A negative resistance value doesn't make sense.

How are you computing the value?

[nalamyogesh]

I have plotted Pressure Drop per unit length against velocity (Values from CFD and not experiments) and then just fitted a quadratic trend line to get coefficients.

[fluid23]

This could just be a figment of your curve fit. The values don't make physical sense as negative, but should work out numerically. Just make sure to set up a report to make sure that the velocity/pressure drop line up with your expected curve.

[nalamyogesh]

That is true. It did not give any errors numerically. Okay, I will have to check the pressure drop reports then.

Thanks a lot.

[Kushal Puri]

Originally Posted by nalamyogesh

That is true. It did not give any errors numerically. Okay, I will have to check the pressure drop reports then.

Thanks a lot.

Some times -ve value comes due to curve fitting, try to remove points from the input data which is looking suspicious and try fitting the curve again. If possible share the curve.