# Chemical Engineering - Fluid Mechanics - Discussion

Discussion Forum : Fluid Mechanics - Section 1 (Q.No. 7)
7.
The head loss in turbulent flow in a pipe varies
as velocity
as (velocity)2
inversely as the square of diameter
inversely as the velocity
Explanation:
No answer description is available. Let's discuss.
Discussion:
10 comments Page 1 of 1.

Abhishek Kumar Singh said:   2 years ago

Mandar Mahajan said:   6 years ago
Darcy Weisbach equation use.

Ap = 4flV^2/2D.
(1)

A. Muthuraja said:   6 years ago

Darcy-Weisbach equation, Hf=4fl(V^2)/(2gd) shows that Hf is directly proportional to velocity^2 and f for Turbulent Flow=0.079/Re: Here Re=pvd/μ.

As f is a dimensionless number (Even V term comes in Co-efficient of friction formula), Hf 4flV^2 is correct. We can also refer Dimensional and Model Analysis.

Option A is wrong (Hf is not various with V).
Option B is Correct (Hf is various with V^2).
Option C is Wrong(Hf is not inversely as the square of diameter).
Option D is Wrong (Hf is not inversely as the velocity).
(3)

Avinash kumar said:   7 years ago
One part of erg equation, which is Burke Plummer equation for turbulent gives the relation of head loss is firstly proportional to velocity squared and inversely proportional to diameter.

Riddhi said:   7 years ago

PRASHANT said:   9 years ago

HL = (F)X(L/D)X(V2/2g).

Where,

F = Friction factor related to the roughness inside the pipe.

L = Length of the pipe.

D = Diameter of the pipe.

V = Average liquid velocity in the pipe.

2g = Two times the Universal Gravitation Constant (g=32.2 ft/sec).

Muhammad Usman said:   10 years ago
Friction factor (f) = (g*D*Head loss) / 2*v^2*L.

This is general equation shows head loss is directly proportional to velocity ^2.

h = (4*f*(l/d)*v^2/2).

Pressure drop in a circular pipe in turbulent flow is proportional to velocity raised to the power of 1.7-1.9.