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.
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.
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)
Variation of Pressure In section and Delivery pipes due to acceleration of the piston
Effect of Acceleration on the Indicator Diagram
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.
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.