Chemical Engineering - Chemical Engineering Basics - Discussion

Friction factor depends on the Reynolds number of the fluid and the Reynolds number depend on the velocity, density and viscosity of the fluid regardless if that fluid is laminar or turbulent, we can say that all choices affect fluid properties except option A, now you might asking whats about option B (pipe roughness), pipe roughness effect fluid velocity that is why.

The only option that doesn't have any effect on the friction factor is the length of the pipe.

Can someone please explain how friction factor depends on mass flow rate of the fluid?

dp=4flv2(density)/2g.

So it should depend upon length.

We can calculate it by equation 16/Re. where Re is the Reynolds no. and as we know that Re = density*vel*dia/viscocity.

hfs = (4flv^2)/2d it's simplifies.

f = (hfs*2d)/(lv^2).

f is doesn't depends on l and v.

But one Formula says that it depends on length.

dh = (4*f)* (l/d)* (u2/density*g)

Than...?

As for Calculating the Fanning Factor density and viscosity required. and then friction factor is 2*fanning factor*length*square of velocity/Dia of Pipe.

SO ITS DEPEND ON LENGTH.

To calculate the velocity (if it is not given) by continuity Eqn. Mass flow is required so I think it does not depend on roughness.

For laminar flow in pipe f=16/Re. & for turbulent flow in pipe f=0.0791*Re^-0.25. And Re depends upon fluid density, dynamic viscosity, dia of the pipe, fluid velocity. So Re does not depend upon length. That is why f is independent of length.

F depends upon Re and Re doesn't depend upon length and roughness depend upon dia only so A.