Reg No.:

Max.

00000CH4011219)zme:
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
B.Tech S7 (S) (PT) Exam Sept 2020

Course Code:CH401
Course Name: TRANSPORT PHENOMENA IN PROCESSES
Marks: 100 Duration: 3 Hours

Use of Photostat copies of the complex equations of the following, duly attested by the concerned faculty

of the

institution shall be permitted in the University examination hall.
1. Tables containing Equation of continuity and equation of motion in rectangular, cylindrical and
spherical coordinate.

2. Tables containing Equations of the components of the stress tensor for Newtonian fluids in

rectangular, cylindrical and spherical coordinate.

3. Tables containing Equation of energy in terms of momentum fluxes and transport properties in

1 a)
b)
c)
2
b)
3 a)
b)

rectangular, cylindrical and spherical coordinate.

PART A
Answer any two full questions, each carries 20 marks. Marks
Explain the concept of molecular theory of the viscosity of gases at low density. (10)

Compute the viscosity of ೮೦) at 200K and 1 atm. Given Q,=1.548, 0=3.996A. (5)

Find the radius of a horizontal capillary of length 50 cm through which water (5)
flows at a mass flow rate of 2.997g/s. The pressure drop in the capillary is found

to be 4.766 x 10° Pa. The kinematic viscosity of water may be taken as 4.03 x 10°

*m?/s.

A cone and plate viscometer consists of a stationary flat plate and an inverted (15)
cone, whose apex just touches the centre of the plate. The liquid whose viscosity

is to be measured is placed in the gap between the cone and plate. The cone is
rotated at a known angular velocity Q , and the torque Tz required to keep the

cone rotating (at steady state) is measured. Find an expression for the viscosity

of the fluid in terms of Q, Tz and യു. For commercial instruments, ೫ is very

small about 1 degree.

Consider an incompressible fluid, at constant temperature, flowin radially (5)
between two porous cylindrical shells with inner and outer radii kR and R.

(a) show that the equation of continuity leads to v,= C/r, where C is a constant

(b) Simplify the components of the equation of motion.

A Newtonian fluid is in laminar flow in a narrow slit formed by two parallel (10)
walls a distance 2B apart. Make a differential momentum balance and obtain
expressions for the momentum flux and velocity distribution. What is the ratio of
average to maximum velocity in that slit?.

Using Navier-Stokes equation, derive an expression for (i) Velocity distribution; (10)
(ii) Maximum velocity; and (iii) Average velocity for the flow of an
incompressible Newtonian fluid flows vertically downward through circular tube

of radius R at steady state.

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