Name
Reg No B
APJ ABDUL KALAM TECHNOLOGICAL UNIVERSITY
07 THRISSUR CLUSTER
FIRST SEMESTER M.TECH. DEGREE EXAMINATION DEC 2017
Mechanical Engineering
(Internal Combustion engines and Turbo Machinery)
07ME6103 ADVANCED FLUID MECHANICS
Time:3 hours Max.marks: 60
Answer all six questions. Part of each question is compulsory.
Answer either part or part of each question
(Gas table is permitted)
Q.no. Module 1 Marks
1a Explain Reynold's Transport Theorem. 4
Answer b or c
b Derive differential form of energy equation 5
c Consider a water storage tank fed by a pipe of diameter 10cm and drained
by a pipe of diameter 6cm. The water enters at a uniform velocity of 3m/s
and leaves at a velocity of 2m/s. Calculate the rate at which the water level
in the tank rises, if the tank diameter is 5m.
5
Q.no. Module 2 Marks
2a Draw and explain velocity profiles for different non dimensional pressure
gradient.
4
Answer b or c
b Two fixed parallel plates kept 8cm apart have laminar flow of oil between
them with a maximum velocity of 1.5m/s. Taking dynamic viscosity of oil
to be 2 Pas. Compute discharge per meter width
ii) the pressure difference between two points 25m apart
5
c A belt conveyer consists of a flat belt of 0-6m wide which slides at a
velocity of 5m/s parallel to a surface separated by a 5cm thick layer of oil
of viscosity 0-3Pas. Find
The pressure gradient required to cause no shear stress at the belt surface
ii) The average velocity and the discharge of oil to be maintained for the
above
5
Q.no. Module 3 Marks
3a Deduce the governing equation for Hagen Poiseuille flow 4
Answer b or c
b Oil of specific gravity 0.92 and viscosity 0.07kg/ms is passing through
12cm diameter pipe. The average velocity of flow is 1.05m/s. Determine
maximum shear stress
ii) local skin friction coefficient
5
c A horizontal pipe of 5cm diameter conveys an oil of specific gravity 0.9
and dynamic viscosity of 0.8kg/ms. Measurements indicate a pressure drop
of 15kN/m2 per meter of pipe length traversed. Make calculations for the
flow rate of oil and centre line velocity
ii) wall shear stress and frictional drag over 100m of pipe length
5
Q.no. Module 4 Marks
4a We can not create a supersonic flow from stagnant condition by using a
convergent nozzle. Why?
4
Answer b or c
b A gas is isentropically expanded from a pressure of 10 bar and temperature
of 798K in nozzle to a pressure of 7.6 bar. If the rate of flow of the gas is
1.5kg/s. Take γ=1.3 and 0.464kJ/kgK. Determine
temperature and velocity at the exit
ii) maximum possible velocity attainable by the gas
iii) exit area
5
c A supersonic nozzle expands air from a pressure of 25bar and temperature
of 1050K to an exit pressure of 4.35 bar; the exit area of the nozzle is
100cm2. Determine:
throat area
ii) temperature at the throat
iii) temperature at exit
iv) exit velocity as a fraction of maximum attainable velocity
mass flow rate
5
Q.no. Module 5 Marks
5a Describe two practical situations where oblique shock waves are produced.
How are strong and weak shocks generated and how do they affect the
flow.
5
Answer b or c
b A normal shock occurs in the diverging portion of a CD air nozzle. The
throat area is 1/3 of exit area and the static pressure at exit is 0.4 times the
stagnation pressure at the entry. Determine
Mx and My
ii) area of cross section of the nozzle at the section of the nozzle where the
normal shock occurs
7
c An air stream at a Mach number of 2 is isentropically deflected by 100 in
the clockwise direction. If the initial pressure and temperature are 98kN/m2
and 970C determine the final pressure, temperature and density of air after
expansion.
7
Q.no. Module 6 Marks
6a Give two examples of Fanno flow in thermal systems, give reasons
justifying Fanno flow in each of these cases.
5
Answer b or c
b Air at a pressure of 0.685 bar and temperature 310K enters a 60cm diameter
duct at a Mach number of 3. The flow passes through a Normal shock wave
at a section L1 meters downstream of the entry where the Mach number is
2.5 The Mach number at the exit (at a distance L2 meters downstream of
the shock) is 0.8. The mean coefficient of skin friction is 0.005. Determine
the length L1 and L2
ii) pressure and temperature of air at the exit
iii) mass flow rate through the duct
7
c A combustion chamber in a gas turbine plant receives air at 350K, 0.55bar
and 75m/s. The air fuel ratio is 29 and the calorific value of fuel is
41.87MJ/kg.
the initial and final Mach numbers
ii) final pressure, temperature and velocity of the gas
iii) percentage of stagnation pressure loss in the combustion chamber
iv) maximum stagnation temperature attainable
7