This document discusses fluid mechanics topics including airfoil theory, reciprocating pumps, indicator diagrams, and examples. It covers how airfoil shape affects lift to drag ratio, how reciprocating pump discharge is calculated, factors that cause slip in pumps, how pressure varies in pump sections and pipes due to piston acceleration, and examples calculating pump parameters and pressure heads on pistons.

1. Fluid Mechanics II
Lecture 9
Muhammad Usman

2. Airfoil Theory
• Angle of inclination depends on the geometerical
position of the body with respect to motion.
• Flat plate inclined at 4 the ratio of lift to drag
force is about 6.
To increase this ratio
• The plate is given a slight curvature in its bottom
• By nicely rounding off the front end of the plate
• Providing sharpe edge in the end.

3. Reciprocating Pump
• L=Length of the stroke
• A= Cross sectional Area
• N= No. Of revolutions per mint.
• Discharge of Water= LAN/60.
• Discarge of water for double acting
pump.=2LAN/60.

4. Slip of Pump
• The difference between actual and
theoretical discharge is known as slip of
the pump.
• Force on the piston during suction
stroke=wHsA
• Force on the piston during delivery
stroke= wHdA
• Power= wQ(Hs+Hd)

5. Indicator Diagram

6. Variation of Pressure In section
and Delivery pipes due to
acceleration of the piston

7. Effect of Acceleration on the
Indicator Diagram

8. Example 1
• A single acting reciprocating pump has a
plunger of diameter 300mm and stroke of
200 mm. If the speed of the pump is 30
r.p.m. and its delivers 6.5 litres/sec of
water find the coefficient of discharge and
the percentage slip of the pump.

9. Example 2
• A single acting reciprocating pump, having
plunger diameter 125 mm and stroke
length 300 mm is drawing water from a
depth of 4 meters from the axis of the
cylinder at 24 r.p.m The length and
diameter of suction pipe is 9 meters and
75 mm respectively. Find the pressure
head on the piston at the begining and
end of the suction stroke, if the barometer
reads 10.3 m of water.

10. Example 3
• A single acting reciprocating pump has plunger
diameter of 200 mm and stroke length 300 mm.
The suction pipe is 100 mm diameter and 8
meters long. The pump draws water 4 meters
below the cylinder axis at 30 r.p.m. Find the
pressure head on the piston.
• At the beginging of the suction stroke.
• In the middle of the suction stroke.
• At the end of the suction stroke.
• Take f= 0.01 and atmospheric pressure head =
10.3 meters of water.