Oil of specific gravity 0.82 is pumped through a horizontal pipeline 150 mm in diameter and 3 km long at rate of ` 0.015 m^3/s`. The pump has an efficiency of 68% and requires 7.5 kW to pump oil. (i) What is dynamic viscosity of oil? (ii) Is flow laminar?

Crude oil of µ = 1.5 poise and relative density 0.9 flows through a 20 mm diameter vertical pipe. The pressure gauges fixed 20 m apart read 600 `(kN)/m^2` and `200( kN)/m^2`, as shown in Figure. Find the direction and rate of flow through the pipe.

 A pipe 60 mm diameter and 450 m long slopes upwards at 1 in 50. An oil of viscosity `0.9 (Ns)/m^2` and specific gravity 0.9 is required to be pumped at the rate of 5 litres/sec.

• (i) Is the flow laminar?
• (ii) What pressure difference is required to attain this condition?
• (iii) What is the power of the pump required assuming an overall efficient of 65%?
• (iv) What is the centre-line velocity and the velocity gradient at pipe wall?