The cause of turbulence in fluid flow may be
In a turbulent flow in a pipe, the shear stress is
In turbulent flow shear stress
r0 = Radius of pipe
y = Distance measured from pipe wall
ζ0 = Shear stress at boundary
In the case of turbulent flows in circular pipes, the maximum velocity um and the mean velocity V are related as (um - V)lu =
For smooth pipe,
g0 = radius of pipe
y = distance measured from pipe boundary
u = shear velocity
from equation (i)
(iii) - (ii) gives
(b) Rough pipe
same for both pipes rough or smooth
The distance from pipe boundary, at which the turbulent shear stress is one-third the wall shear stress, is
In turbulent flow shear stress at distance y from pipe boundary,
A flow in which the quantity of liquid flowing per second is not constant, is called
A fluid motion is said to be turbulent when the fluid particles move in an entirely haphazard or disorderly manner, that results in a rapid and continuous mixing of the fluid leading to momentum transfer as flow occurs. At any point in a turbulent flow the velocity and pressure are the functions of time thereby rendering such a flow as unsteady.
Which of following conditions would entail a greater energy dissipation in turbulent flow?
1. Smaller eddy size
2. Lower viscosity
3. Large intensity ofturbulence
Select the correct answer using the codes given below:
Match List-I (Nature of flow) with List-II (Friction factor equation) and select the correct answer using the codes given below the lists:
1.Turbulent flow with rough boundary
2. Turbulent flow with smooth boundary
3. Turbulent flow with Re < 105
4. Laminar flow
Turbulent flow generally occurs
When Re < Rec Laminar flow occurs at very small velocities or through narrow passage (small d) or for highly viscous fluids (high v) the Re will be small and flow will remain laminar. For high velocities through large passage Reynolds number will be sufficient to cause turbulence.
A pipe line carrying water has surface-protrusions of average height 0.10 mm. If the shear stress developed is 7.85 N/m2, then the pipe surface will act as
Since roughness value lies between 4 and 100 the pipe act as in transition.