[BAE303/BAS303]
Model Question Paper-1/2 with effect from 2022-23 (CBCS 2022 Scheme)
USN
Third Semester Aeronautical /Aerospace Engg. B.E. Degree Examination
[Fluid Mechanics]
TIME: 03 Hours Max. Marks: 100
Note: 01. Answer any FIVE full questions, choosing at least ONE question from each MODULE.
Bloom’s
Question
Description Taxonomy CO Marks
No.
Level
Module 1
01 (a) Distinguish between manometers and mechanical gauges.
What are the different types of mechanical gauges used L1 3 8
explain briefly?
(b) Prove that the intensity of pressure at a point in static field is
L2 1 6
equal in all directions.
(c) What are the gauge pressure and absolute pressure at a point
3m below the free surface of liquid having density of 1.53*103
kg/m3 if the atmospheric pressure is equivalent to 750mm of L3 2 6
mercury? The specific gravity of mercury is 13.6 and density
of water is 1000kg/m3.
(OR)
02 (a) Prove that the rate of increase of pressure in a vertically
downward direction must be equal to the specific weight of L2 1 8
fluid at that point.
(b) Prove that centre of pressure lies below the centre of gravity
L2 1 8
of vertically immersed plane surface in a static fluid.
(c) A stone weighs 392.4N in air and 196.2N in water. Compute
L3 2 4
the volume of stone and its specific gravity
Module 2
03(a) Derive the general three dimensional continuity equation and
then reduce it to continuity equation for steady, two L2 1,2 12
dimensional in compressible flow.
(b) The velocity potential function is given by expression ϕ = -
xy3/3 – x2+x3y/3+y2 L3 2 8
i) find the velocity components in x & y directions.
ii)show that ϕ represents possible case of fluid flow.
(OR)
04(a) Derive an expression of energy equation in global form of
L2 1,2 10
conservation equation
(b) Obtain an expression in differential form for navier stokes
L2 1,2 10
equations .
Module 3
[BAE303/BAS303]
05 (a) Derive the Euler’s equation of motion for steady flow and
obtain Bernoulli’s equation from it. State the assumptions made L2 1,2 10
in derivation of Bernoulli’s equation
(b) Explain a venturimeter. Derive an expression for discharge.
L2 1,2 10
Why venturimeter is better than orifice meter?
(OR)
06 (a) The pressure difference Δp in a pipe of diameter D and length l
due to viscous flow depends on the velocity V, viscosity µ and
L3 2 10
density ρ. Using Buckingham’s π- theorem, obtain an
expression for Δp.
(b) The resisting force R of supersonic plane during flight can be
considered as dependent upon the length of the aircraft l,
velocity V, air viscosity µ, air density ρ and bulk modulus of L3 2 10
air k. express the functional relationship between these
variables and resisting force.
Module 4
07 (a) Derive an expression for a lift force on rotating cylinder which
L2 1,2 10
represents kutta- joukowsky equations?
(b) What are the boundary layer conditions that must be satisfied
L2 2 10
by a given velocity profile in laminar boundary layer flows.
(OR)
08 (a) Obtain von karman momentum integral equation. L2 2 10
(b) Air flows at 10m/s past a smooth rectangular flat plate 0.3m
wide 3m long. Assuming that the turbulence level in the
oncoming stream is low and that transition occurs at Re =
L3 2 10
5*10^5, calculate ratio of total drag when the flow is parallel
to the length of the plate to the value when flow is parallel to
width
Module 5
09 (a) Briefly explain the concept of propagation of disturbances in
L2 1,2,3 10
fluid and derive an expression for velocity of sound.
(b) Show by means of diagrams the nature of propagation of
disturbance in compressible flow when mach number is less L3 1,2,3 10
than one, is equal to one and is more than one.
(OR)
10(a) State bernoulli’s theorem for compressible flow. Derive an
expression for bernoulli’s equation when the process is L2 2 10
isothermal process
10(b) Find the mach number when an aeroplane os flying at
1100km/hr through still air having pressure of 7N/cm2 and
temperature -50C. wind velocity may be taken as zero. Take R L3 2 10
= 287.14J/kgK. Calculate the pressure, temperature and density
of air at stagnation point on the nose of the plane. Take k = 1.4
[BAE303/BAS303]
Model Question Paper-2/2 with effect from 2022-23 (CBCS 2022 Scheme)
USN
Third Semester Aeronautical /Aerospace Engg. B.E. Degree Examination
[Fluid Mechanics]
TIME: 03 Hours Max. Marks: 100
Note: 01. Answer any FIVE full questions, choosing at least ONE question from each MODULE.
Bloom’s
Question
Description Marks CO Taxonomy
No.
Level
Module 1
1 (a) What is temperature lapse rate? Obtain an expression for
L2 2 8
temperature lapse rate.
(b) Prove that pressure and temperature for an adiabatic process at a
height z from sea level for static air are
k−1 gZ k/k-1
a. P = P0 [1-( ) ] L3 2 12
k RT0
k−1 gZ
b. T = T0[1-( ) RT0]
k
(OR)
02 (a) Give reasons for the following:
a. Viscosity changes with temperature rise
b. Mercury is preferred in manometer liquid
L1 1,2 8
c. Light weight objects can float on the free surface of
liquid.
d. Free surface of water in capillary tube is concave
(b) Explain the phenomenon of capillarity. Obtain an expression for
capillary rise and capillary fall. L2 2 8
(c) Determine the specific gravity of fluid having viscosity L3 2 4
0.005Ns/m2 and kinematic viscosity 0.05*10-4 m2/s.
Module 2
03(a) A source and a sink of strength 4m /s and 8m2/s are located at (-
2
1,0) & (1,0) respectively. Determine the velocity and stream L3 2 10
function at a point P(1,1) which is lying on the flownet of the
resultant streamline.
(b) Obtain an equation of stream function & potential function. Draw L2 2 6
stream line and potential lines for source flow.
(c) Given the velocity field, V = 5x3 i – 15x2 yj, obtain the equation
for streamlines. For above given velocity field, check for the L3 2 4
continuity and irrotationality.
(OR)
04(a) Obtain an integral form and differential form of energy equation
L2 2 10
using control volume approach.
[BAE303/BAS303]
(b) Derive the Navier stokes equations by control volume approach.
Mention the applications of continuity, momentum and energy L3 2 10
equations.
Module 3
05 (a) The inlet and throat diameters of a horizontal venturimeter are
30cm and 10cm respectively. The liquid flowing through the
meter is water. The pressure intensity at inlet is 13.734N/cm2 L3 2 8
while the vacuum pressure head at the throat is 37cm of mercury.
Find the discharge of water through venturimeter. Take Cd=0.98.
(b)
Find discharge through a trapezoidal notch which is 1m wide at the
top and 0.40m at the bottom and 30cm in height. The head of water
L3 2 6
on the notch is 20cm. Assume Cd for rectangular portion = 0.62
while for triangular portion = 0.6
(c) Obtain an expression for discharge over a rectangular notch with
L2 1 6
neat sketch.
(OR)
06 (a) Derive on the dimensional analysis suitable parameters to present
the thrust developed by a propeller. Assume that the thrust P
depends upon the angular velocity ω, speed of advance V, diameter
L3 2 10
D, dynamic viscosity µ, mass density ρ, elasticity of the fluid
medium which can be denoted by the speed of sound in the
medium C.
(b) A test was made on a pipe model 15mm in diameter and 3m long
with water flowing through it at the corresponding speed for
frictional resistance. The head loss was found by measurement to
be 7m of water. The prototype pipe is 300mm in diameter and
240m long through which air is flowing at 3.6m/s. density of water L3 2 10
and air is 1000kg/m3 and 1.22 kg/m3respectively and coefficients
of viscosity of water and air are 0.01 & 0.00018 poise. find i) the
corresponding speed of water in the model pipe for dynamic
similarity. ii) pressure drop in the prototype.
Module 4
u πy
07 (a) For the velocity profile for laminar boundary flowU = sin[ 2δ ].
Obtain an expression for boundary layer thickness, shear stress, L2 2 10
drag force on one side of the plate and coefficient of drag in terms
of Reynolds number
u y
(b) For velocity profile for turbulent boundary layer U = [δ] (1/7), obtain
an expression for boundary layer thickness, shear stress, drag force
L2 2 10
on one side of the plate and coefficient of drag in terms of
µ
Reynolds number. Given τ0 = 0.0225ρU2[ ] (1/4)
𝜌𝛿𝑈
(OR)
08 (a) Define and obtain expression for: L2 1,2 10
[BAE303/BAS303]
i) displacement thickness ii) momentum thickness iii) energy
thickness
(b) Consider two different points on the surface of the airplane wing
flying at 80m/s. the pressure coefficient and flow velocity at point
1 are -1.5 and 110m/s, respectively. The pressure coefficient at L3 2 6
point 2 is -0.8. assuming incompressible flow, calculate the flow
velocity at point 2
(c) With neat sketch, explain the airfoil characteristics. L1 2 4
Module 5
09 (a) Derive an expression for the velocity of sound wave for
compressible fluid when process is assumed as i) isothermal & ii) L2 2 10
adiabatic.
(b) Calculate the stagnation pressure, temperature and density on the
stagnation point on the nose of a plane, which is flying at
L3 2 10
800km/hr. through still air having pressure 8N/cm2(abs),
temperature -10oC. Take R = 287.14J/Kg K and k = 1.4
(OR)
10(a) Derive an expression for stagnation pressure, temperature and
L2 2 15
density for compressible flow.
10(b) Find the velocity of bullet fired in standard air if the mach angle is
30o. Take R = 287.14J/kg K and K = 1.4 for air. Assume L3 2 5
temperature as 15oC.
