Question

Hi, i want 5 (report) conclusions for each topic
1-The application of Bernoulli’s equation
2-Major&Minor Losses in Pipes

Answer 1

Applications of Bernoulli's theorem:

1. Flying of Aeroplane

Due to aerofoil shape, air speed is more at top of aerofoil than bottom. This difference in pressure lifts the aeroplane.

2. Venturi meter

Due to reduction in area of venturi meter velocity increases as a result pressure drops. The difference between pipe pressure and reduced section pressure is used to calculate flow rate of the flow.

3. Blowing of off roofs of houses during Strom

Similar things happens like aerofoil. Due to pressure difference lift generated.

4. Attraction between two parallally moving boats (closely)

Due to speeds of boats, water between them moves faster which leads to pressure drop. Thus boats attract each other.

5. Atomiser working

High speed air is blown over a tube which is dipped in paint, scent, petrol etc., Due to high speed low pressure created at top which sucks out fluid through tube.

Major and Minor losses:

Major losses are high and unavoidable compared to minor losses.

Major losses occurs due to pipe friction due to flow over a length. Major losses is given by Darcy equation,

Major head loss, h = fLV^2/2gD

f = Coefficient of friction

L = Length of the pipe

V = velocity of flow

g = acceleration due to gravity

D = Diameter of pipe

Minor losses occurs due to geometrical discontinuities.

Minor losses = k(V^2/2g)

k depends on geometry

For 45degree elbow, k=0.35

For 90degree elbow, k= 0.75

For return bend, k = 1.5

For sudden entrance, k=0.5

For coupling, k = 0.05

Conclusions:

1. Major losses are unavoidable unlike minor losses.

2. Major losses depends on length and minor losses don't.

3. Major losses are global and minor losses are local.

4. Minor losses are small compared to major losses.

5. Pipe Friction is reason for major losses and geometrical discontinuities are reason for minor losses.