# JNTU,B.Tech I Semester FLUID MECHANICS, November 2008

JNTU,B.Tech I Semester FLUID MECHANICS, November 2008

(Chemical Engineering)

SET-4

1. Derive the equation for the interfacial height in a gravity decanter. 

2. (a) A pipe line tapers from 10cm dia to 4cm dia. The quantity of water flowing

the pipe is 0.15m3/sec. Calculate the average velocity at the two sections.



(b) Write one dimensional equation of continuity. 

3. Show that for a Newtonian fluid flowing in laminar flow through a pipe , the ratio

of average velocity to maximum velocity 0.5. 

4. (a) Calculate the hydraulic mean diameter of the annular space between a 40 mm

and a 50 mm tube. 

(b) A liquid having density of 0.97 gm/cc and a viscosity of 0.347 cp is flowing

through a pipe of diameter 10.2 cm with a velocity of 75 cm/s. Calculate the

Reynold’s number. 

(c) A steel pipe 2 ft in diamter carries water at about 15 ft/s. If the pipe has a

roughness of 0.0003ft, could he capacity be increased by inserting a smooth

plastic liner that reduces the inside diameter to 1.9 ft? Calculate the change in

pressure drop for the same flow and the charge in capacity for a fixed pressure

drop. 

5. Explain adiabatic compression. Derive the equation for shaft work for adiabatic

compression. 

6. Derive Ergun equation to calculate pressure drop through bed of solid particles.



7. Estimate the minimum fluidization velocity for a bed of particles fluidized by water

using the following data: Diameter of the particle = 120 ?m; sphericity =1; density

of the particle = 2500 kg/m3; density of water is 1000 kg/m3 ; minimum porosity

is 0.45; viscosity of water is 0.001 kg/m s. 

8. Sulphuric acid of specific gravity 1.3 is flowing through a pipe of 5 cm ID . A thin

tipped orifice os 1cm diameter is fitted in the pipe and the differential pressure

shown by the mercury manometer is 10 m .Calculate the weight of acid flowing per

hour . Take the orifice coefficient as 0.61.