JNTU II B-Tech I Semester Supplimentary Examinations,Fluid Mechanics For Chemical Engineering November 2008


JNTU II B.Tech I Semester Supplimentary Examinations, November 2008

                                                          Fluid Mechanics For Chemical Engineering

(Chemical Engineering) SET-3



1. A centrifuge bowl 30 cm in I.D. is rotating at a speed of 60 revolutions per second.

It contains a 5 cm layer of a liquid of specific gravity 1.6. If the system is open to atmosphere, estimate the gauge pressure exerted at the walls of the centrifuge bowl.


2. (a) State the Bernoullis equation? Explain the significance of each term.

(b) Write any two applications of the Bernoullis equation.

(c) Write short notes on Average velocity.


3. What is Reynolds number? Explain the variation of friction factor with Reynold’s

number for turbulent flow, in smooth and rough pipes along with corresponding formulae.


4. Derive an expression for pressure ratio of an isentropic flow in terms of Mach number.


5. (a) Explain about the criterion for the settling regime.

(b) Estimate the terminal velocity for 0.161mm diameter particle having a density of 2800Kg/m3 falling in water under the influence of centrifugal force.(CD= 1.2).


6. A sand filter employs a 70 cm high bed of silica sand above a layer of coarse gravel.

The sand is of 2.55 specific gravity, has a bed voidage of 0.45 and the following size distribution is given:


Diameter of particle (m) × 104    5.5   5.8   6.4   6.9    7.4   7.9   8.5   9.1  10.0  10.4

Weight fraction(X)                    0.1   0.1   0.1   0.1    0.1   0.1   0.1   0.1   0.1    0.1

This sand bed is to be back washed with a velocity of 0.0125m/s.

(a) Determine the length of the expanded bed.

(b) Determine the pressure drop of the fluidized bed.


7. (a) ”A piping network will be subjected to varying temperatures.” Discuss the necessary arrangement for this network.

(b) Give a brief account of precautions to be taken in designing & installing of a piping system.


8. (a) Derive the equation for the velocity of the fluid at the throat of the venture meter.

(b) A venturi meter having a throat diameter of 38.9 mm is installed in a line having an inside diameter of 102.3 mm. It meters water having a density of 999 kg/m3. The measured pressure drop across the venturi is 156.9 kPa. The venturi coefficient is 0.98. Calculate the flow rate in m3/s.

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