VEDA FM flow through pipes

The Darcy-Weisbach equation for loss oThe Darcy-Weisbach equation for loss of head can be expressed mathematically:f head can be expressed mathematically:

• hf =(4fvl²)/2gd

• hf =(4flv²)/2gd

• hf =(4lvf²)/2gd

• None of these

In the context of fluid flow, what does the term 'head loss' refer to?

• The energy loss due to friction

• The velocity of the fluid

• The total energy of the fluid

• The pressure increase in the system

Which of the following factors does NOT influence head loss in a pipe system?

• Length of the pipe

• Roughness of the pipe surface

• Temperature of the fluid

• Type of fluid

Among the head losses, the most significant head loss in a laminar pipe flow is due to​ (a)  

• friction
• Gradual contraction
• Sudden contraction
• Sudden enlargement

For viscous flow the coefficient of friction is given by

• 16/Re

• 32/Re

• 60/Re

• 8/Re

Answer explanation

Three pipes are connected in series, then the :

• Discharge through each pipe is the same

• Head loss in each pipe is the same

• Total discharge is the sum of discharges in individual pipes

• Reynolds number of each pipe is the same

Answer explanation

Three pipes are connected in series, then the Discharge through each pipe is the same

Head loss is additive

The flow in the pipe is laminar if:

• Reynold is equal to 2500

• Reynold number is equal to 4000

• Reynold number is more than 2500

• None of these

Answer explanation

The laminar flow is characterized by

• irregular motion of fluid particles

• fluid particles moving in layers parallel to the boundary surface

• high Reynolds number of flow

• existence of eddies

Answer explanation

Laminar flow is a type of fluid flow where the fluid moves smoothly in parallel layers (also called streamlines), with minimal mixing between the layers. It is the opposite of turbulent flow, which is chaotic and involves eddies and vortices.

Equations of viscous fluid motion are analysed by

• Euler’s equations

• Navier Stokes equation

• Bernoulli equations

• Hagen-Poiseuille equations

Answer explanation

Navier-Stokes equation: This is the fundamental equation used to analyze viscous fluid flow. It accounts for viscosity, pressure, body forces, and the inertial forces in a fluid.

An ideal fluid is one which

• Obeys Newton's law of viscosity

• Flows through pipes with least friction

• Is friction-less and in-compressible

• Satisfies continuity equation

Answer explanation

An ideal fluid is a theoretical concept used in fluid mechanics with the following characteristics:

• Incompressible: Its density does not change with pressure.

• Frictionless (zero viscosity): No internal resistance to flow; it does not obey Newton’s law of viscosity.

• Irrotational: The flow has no vortices.