Jawaharlal Nehru Technological University Hyderabad 2007 B.E Chemical Engineering TRANSPORT PHENOMENA - Question Paper

1. (a) What is transport phenomena? Write the Newton’s legal regulations of viscosity, Fourierslaw
of heat conduction and Ficks legal regulations of diffusivity and discuss why these
three laws can be considered analogous.
(b) A flat plate 15 m long has an edge facing the flow direction. Air is flowing
over the plate at 1000 cm/s. The air properties are  = 1.32 gm/lit. and µ =
0.018 cp. compute the boundary layer thickness at 125 cm from the leading
edge. [16]
2. Derive the momentum and velocity distribution formula for a fluid flowing through
a circular tube. The flow is laminar and steady. [16]
3. Derive an formula for the temperature distribution in laminar tube flow. [16]
4. Air at 270C flows normal to a 730C, 30mm o.d. water pipe. The air moves at 1m/s.
Estimate the rate of heat transfer per unit length kinematic viscosity=1.624m2/s,
Thermal conductivity=0.0261W/mk, Npr for air=0.702 [16]
5. Chlorine is being absorbed from a gas in a small experimental wetted wall tower.
The absorbing fluid is water, which is moving with an avg. velocity of 17.7
cm/sec. What is the absorption rate in g moles / hour if DCl2-H2O = 1.26 ×10-5
cm2/sec. in the liquid phase and if the saturation concentration of chlorine in water
is 0.823 g Cl2 per 100 g of water. Ignore chemical reaction ranging from Cl2 and H2O.
The tower height is 13 cm and radius 1.4 cm. [16]
6. discuss the following:
(a) The partial time derivative
(b) Total time derivative
(c) Substantial time derivative
(d) Navier-stokes formula [4×4=16]
7. Consider an isothermal incompressible fluid radially ranging from 2 porous cylindrical
shells. presume steady, axisymmetric, laminar flow and neglect the end effects.
(a) find a differential formula using the formula of motion.
(b) Solve the above formula and obtain the raidal pressure distribution along the
radius of the pipe. [6+10]
8. Show that the ratio of avg. to maximum velocity for turbulent flow in smooth
circular tube is
V z
V zMax
= 2n2
(n+1)(2n+1) [16]

Earning:   Approval pending.