w-897'Ibtal No. of Pages : 3Seal

No.

Q1) a)

b)

: 96 cm.

: 6g*:1.61:1: 5.8:1

: 0.014 W + 0.046 AV2

B.Ii. (Mechanical) (Part - IV) (Semester - VII) (lleviscd) (Nerv)

Examination, June - 2014

AUTOMOBILE EI{GII{EEIiIN{G (Elcctive - I)

Sub. Code | 47984

Day and Date : 'fucsday, 03 - 06 - 2014 'fotal Marks : 100

'I'ime : 10.00 a.m. to 1.00 p.m.

Instructions : 1) Anslver any three qucstions from each section.

2) Figures to right indicate full marks.

3) Draw neat sketches wherever nccessary.

4\ Assume suitable data rvhcrever necessary.

SECTIO}i . I

L,xplain with suitable layout diagrarn how power is transmitted to drivingwheels in case of four rvheel drive . 17l

A commercial vehicle having a mass of 7000 kg is provided r.vith a diesel

engine. The rated power ofthe engine is 70 kW at 2500 rprn. The maximum

torque produced by the engine is 315 N-m at 1400 rpm. Ihe transmission

losses at 2500 rpm & 1400 rpm can be taken as 10 kW and 5 kWrespectively. Calculate the grade that vehicie can climb in 3'd gear. t10l

D At rated speed

ii) At the speed when torque is maximum

Take.

Effective diameter of whcel

Projected frontal area'l'hird gcar ratio

Rear axle ratio

Road resistance

Where.

W - u,eight of vehicle in N, t\-frontal area in nr2 and

Y - Speed of vehicle in kmth

nT.o.

w-897Q2) a) What do you mean by clutch free paddle play? Why is it necessary?

How is it adjusted? I8l

b) State at least eight requirements of good clutch. t8l

e3) a) What is interlocking? With sketch illustrate the operation of inter-locking

mechanism.

b) With detailed sketch explain the operation of synchromesh unit.

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Q4) a)

b)

What is the Epicyclic gear-box? Describe its principle with neat sketch. [8]

What are the functions of final drive? State various Upes of gears used

for final drive. State the advantages of worm andwheel alrangement.[9]

SECTION. IIQ5) a) In what respects is the steering system of a 3- wheeler different from

steering system of 2 and4 wheelers? Discuss the salient features in the

consffuction of fork of a 3-wheeler. I8l

b) A Cielo GLE car has a wheelbase of 2520 mm and pirot centre of 1100

mm. The front and rear wheel tracks are 1400 mm each. If the 157 inside

lock angle is 43o, determine

r) the correct outside lock angle, and

ii) maximum and minimurn turning circle radius.

e6) a) What is a tandem master cylinder? What are its advantages over an

ordinary master cylinder. tsl

b) Maruti swift car has kerb weight of 9700N and wheelbase of 2520 mm.

Its C.G. is 1250 mm in front of rear axle and 655 mm above the level

road. The co-efiicient of road wheels adhesion is 0.6. If a car is moving

upward on a road inclined at anangle 25" with the horizontal. Calculate

the load distribution on the front & rear axles, the acceleration or

retardation and the stopping distance when, while moving at 60 lanph. [121

D the front brakes are aPPlied

ii) rear brakes are aPPlied and

d) all the four brakes are aPPlied.

The seating capacity of the vehicle is for 5 persons including the driver.

Take weight of each Person as 600N.

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w-897Q7) a) Classify shock absorbers from various view points. Explain the working

principle of a hydraulic shock absorber.

b) Write notes on the following:

r) Pitching & rolling

ii) Sprung & unsprung weights

rii) Hotchkiss drive.

QB) a) Several2-wheelers employ an "Auto start" system now a days. Througha circuit diagram, explain the working of this system.

b) Write notes on the followrng:

,) Sulphation, its causes and symptoms.

ii) AlkalineBatteries.

rii) Combined voltage & current regulator.

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w-900Total No. of Pages : 4Seat

No.

B.E. (Mechanical) (Part - r) (Semester - vII) (Revised) (i{ew)Examination, June - 2014

FINITE ELE MENT ANALYSISSub. Code z 47981

Day and Date : Thursday, 05 - 06 -2014 Total Marks : 100Time : 10.00 a.m. to 1.00 p.m.

rnstructions: 1) solve any three questions from each section.2) Figures to the right indicate full marlis.3) Assume if necessary suitable data and state them clearly.4) Draw neat labeled skptch wherever necessary.5) Use of non-programmable calculators is permissible.

SECTION - I

Q1) The equation governing the torsion of a circular shaft ir 1:(JG/L)0, where Tis the torque, J is the second moment of area of the cross section, G is theshear modulus, L is the length and e is the angle of turist of the shaft inradians. Derive the finite element equations for the torsion elements and analyzethe shaft fixed at end supports given in the figure below. (i.e., find nodaldisplacements and support reaction torques by discretizngthe shaft into threeelements). Take diameter of the shaft:20mm and G:80 GPa 116I

10Nm (CW) 20Nm(CCW)

[-,--l*,"-+-#-'l

P.TO.

Q2) a)

Q3) a)

b)

w-900

The beam element shown in figure below has two vertical displacements

v and v,andtwo rotations Q, *A 0, defined at the end points (nodes)'

The displacement equation is

t: ar+ o{ + arx2 + aox3

where, ar: r,, at:3llz (v, - v,) -lll (2e, - 0r)'

or: A,,ao:2lP (v,-v,)-ll12 (20,- 0r)

Develop the shape functions (N,,N, N, N) for

equation glven below.

V,,, : N, v, * N, 0,+ N, v, * No 0,

the interPolation

,,ol oij-

Explain general steps of FEM using a simple l-D element for sffess

analysis of a stePPed bar t8l

OR

Thermal analysis of heat conduction through a composite wall'

Explain with suitable example discretization and boundary conditions' [8]

Explain the importance of element shape and distortion in relation to

q,rufity of the finite element mesh' t8l

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b)

Q4) Write short notes on: (any three):

a) Properties of stifhress matrix'

b) Boundary Value Problems'

c) Galerkin's Method'

d) Features of a commercial FEA package'

e) Concept of functional and its minimization'

[18]

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TQs) a)

w-900SECTION . IT

For a fully developedlamrnar tlow rn a p1Pe,1b.e rrlu:e la"m :ate Q lS

related tothe p..r**. gradient by t8l

- nD4 dP( i_---*- lzlp d*

where, pis dynamic viscosity of the fluid, and d is the pipe diameter'

Taking a pipe of length / as a finite element, write element equations in

the form iql : [C] {P}, (IJse, F: EA (dr/dx) analogy)'

,) In a beam element of length /, a transverse point force F is applied

at a distanc e of ll4from left hand side. Write the load vector due to

this load. F

,r'"L .,I

ii) The heat generation in a two-noded element is 500Wm and the

length of the element is lcm. Write the heat flux vector due to this

heat generation-

b)

i+licm

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Q6) If the nodal displacements of the elements in figure below are found to be z :2,v,:2,uri i,v,:0,ilu:3,v0: I pm. Find the displacements at the point

Q,2)? 'r 'L

t16l

(Note area of triangle tlk, A: A, * 4 * An)

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w-900Q7) a) What are simplex, complex and multiplex elements used in FEM? t8l

b) Explain the importance of element shape and distortion in relation toquality of the finite element mesh. t8l

Q8) Write short notes on. (any three) t18I

a) Bandwidth of stiffness matrix and its significance.

b) Different boundary conditions applied in fluid flow analysis.

c) Continuity conditions (Co, C,) for interpolation functions.

d) Features of a commercial FE packag€, e.8., ANSYSA{ASTRANAIISA.

e) Post-processing.

'.ff

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w-896Total No. of Pages : 3

SeatNo.

Day and Date: MondaY,A2-06-2A14Time : 10.00 a.m. to 1.00 P.m.

lnstructions: 1)

2\3)4)

s)

B.E. (Mechanical) (Part-I) (Semester-Vll) (Revised) (New)

Examination, June-2014

MECHANICAL SYSTEM DESIGI\Sub. Code z 47980

Total Marks : 100

Solve any three questions from each section.

Figures to right indicates full marks to the question.

Answer to both the section must be write in single answer book

Draw neat labelled sketch wherever necessary and use ofprogrammable calculator is allowed.

Assume any data if necessary and state it clearly'

SECTION.I

Q1) a) What are different types of displays? Explain the ergonomict8Iconsiderations in the design of displays.

b) Explain following with respect to asthetic design: t8l

r) Form

ii) Symmetry and balance

iii) Color

10 SUle

e2) a) Explain Area for Area method of compensation for nozzle in unfired

t8l

b) ff:if:J'iiillrr,"n ror torque transmission capacity or plate clutc;

assuming uniiorm wear theory (pr : C). t8I

e3) a) An automotive vehicle weighing 10 kN and moving on the level road at a

speed of 100 Kmihr is brought to the rest in 4 seconds by applying the

brakes on all four wheels. The mass moment of inertia of each wheel

about the axis of rotation is 0.75 Kg-m'. The rolling radius of the wheel

is 0.175m. The rotating and reciprocating parts of the engine and

transmission system are equivalent to a mass moment of inertia of 2.5

P.TO.

w-896kg-*' at 4000 rpm. The mass of each brake dmm assembly is 10 Kg.The specific heat of the brake drum is 500 J/kg"C.

Calculate:

D The temperature rise of the brake drum assembly and

ii) The braking torque capacity of each brake.

b) A long thick steel tube of inner diameter 150mm is subjected to an externalpressure of 20 N/mm2. The allowable compressive and tensile stresses

for the tube are 160 N/mmz and 100 N/mm2 respectively. Determine the

outer diameter of tube using:

r) The maximum principal stress theory; and

ii) The maximum shear stress theory.

Derive the expression you use.

Q4) a) Discuss the considerations used in design of centrifugal clutch. t8Ib) Derive an expression for braking torque required in case of internal

expanding brakes.

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Q5) Write short notes onAny Three of the following: [16]a) Modeling of masses and inertia.

b) Failure criteria ofvessels.

c) Compound cylinders.

d) Relationbetweenman-machine-environment.

e) Difference between lumped system and distributed system.

SECTION.II

Q6) a) Explain significance ofnormal distribution curve and state its limitations.

b) What is purpose of idlers? Explain any two of them.

Q7) a) A six speed gear box is to be designed for a machine tool drive. The

spindle speed ranges between 150 rpm and 1000 rpm. If the gear box isdriven by 5 kW, 1000 rpm. electric motor through the drive;

,) Draw the speed diagram.

ii) Draw the gearing diagram.

d) Determine the number of teeth or gear.

1

1v) Select the diameters of the pulleys for the belt drives'

The standard pulley diameters are : 80, 90, 1 00, l|2, 125, 140, |60,

2oo, 224, 250, 280, 2g0, 300,310, 355, 37 5, 40A,450, 500 rpm'

Assume same module for all gears'

b) Explain the procedure to estimate the power requirement of the

conveyors.

Q10)Write short notes on AnY Three:

a) Chain conveyors.

b)Roleofreliabilityinmodernengineeringdesign.c) Pressure vessel SuPPorts'

d) Optimization of structure design'

e) Auto frettage.

w-896

180,

[101

belt

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Q8) a) A beam of rectangular cross section is subjected to a maximum bending

moment of 40 Kn-m and amaximum shear force of 150 kN. It is required

that the depth 'd' of the beam shall not exceed twice its width 'b'. Using

maximum shear stress theory. Design the beam with objective of

minimizing the cross sectional area.Use the following data; t8l

D Maximum bending stress induced in beam' o' =#

ii) Average shear stress induced in beam' ' =ffi

d) Allowable tensile stress for beam: 100 N/mm2'

,g Allowable shear stress for beam: 50 N/mm2'

b) List objectives of optimum design'

Q9)a)Writeanoteongraphicalrepresentationofspeed.tSlb) Explain with suitable design adequate design and optimum design' t8l

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oaoaa

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w-895Total No. of Pages : 4Seat

No.

Day and Date : Saturdap 31 - 05 - 2014

Time: 10.00 a.m. to 1.00 p.m.

B.E. (Mech.) (Part - I) (Semester - VfD (Revised) (New)Examination, May - 2Al4

REFRIGERATIOI\ AND AIR CONDTTIONINGSub. Code 2 47979

[nstructions : 1) Attempt any three questions from each Section.2) Figures to the right indicate full marks.3) Use same answer books for the two sections.4) Neat diagrams/charts must be drawn wherever necessary.

5) Use of steam tables, refrigerants/psychometric charts / tables areallowed.

6) Make suitable assumptions if required and state them clearly.

SECTION . I

Ql) a) Differentiate between physical and thermodynamic properties of a

refrigerant. Explain which are more important grving specific reasons. [10]

b) Give different types, compositions, properties and applications of anyfrirro azetro,es. t6l

Q2) a) Enumerate the various methods of air refrigeration system and explainany one of them with neat sketch.

b) Explain the dif[erence between multievaporator and cascade refrigerationsystem and describe two stage cascade refrigeration system giving itsadvantages.

Q3) a) Give the procedure to charge and testing of a refrigerant into a refrigerationsystem. Explain how leak is detected?

b) Explain the working of an externally equalise thermostatic expanslon

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PTO.

Total Marks : 100

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device with a neat sketch.

w-89sQ4) a) Explain why the coefficient of perfornance of a heat pump is always

larger than unity? l4l

b) The ozone ftiendly refrigerant R134a is used in vapour compression

refrigeration system operating at a condenser temperature 40oC and an

evaporator temperature of OoC develops 20 Tons of refrigeration using

the property tables. Cp at P* : 1.145 kJikgoK, Deteffnlne:

D The discharge temperature and mass flow rate of the reftigerant

circulated.

ii) The theoretical piston displacement of the compressor and Piston

displacement per ton of refrigeration.

lii) The theoretical horsepower of the compressor and horsepower

per ton of refrigeration.

The heat rejected in the condenser and

The Carnot COP and actual COP of the cycle.

,9

v)

[121

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Q5) Write notes on any three of the following:

a) Lithium bromide water vapour absorption system.

b) Flooded type evaporators.

c) Claude cycle.

d) Alternativerefrigerants.

e) Crystallization.

SECTION . II

Draw the comfort chart. Show all the details. Explain how it is used?

What are the limitations of the same? What are the different factors whichQ6) a)

influence human comfort?

a

w-89sb) Explain the self regulatory system of the body against high temperatureand low temperature exposure. Ul

Q7) a) Describe the equal friction method of duct design. Compare with staticregain method of duct design. I7l

b) Define blow, drop or size, induction ratio in case of duct outlets used inair distribution system. Give types and uses of outlets, diffiisers, registers,dampers used in air distribution system. pl

Q8) a) Describe dehumidification process, why it is necessary in air conditioningpractice. State the eqpts required for the purpose. t6l

b) The condition of air at a particular place are as follows [101

Qe) I4la)

b)

DBT :24oc, DPT : 15oc, Atmospheric pressure : 740mmof Hg find

D Partial pressure of water vapour and dry air

ii) Relative humidiry

iii) Absolute humidiry

,g Specific humidity

v) Specific enthalpy without using psychometric chart.

Define and explain meaning of RSFIF and GSm.

The following data relates to the office air conditioningplant

outside design conditions -+ 40oC DBT & 30.C WBT

Inside design conditions -+ ZT,CDBT & 60% RH

The total sensible heat load -+ 100 kW

The total latent heat load + 40 kW

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w-895

60% of the return air is recirculated and mixed with 40o/o of make up air

after the cooling coil. The condition of air lcaving the cooling coil is

18"C. Determine:

r) Room sensible heat factor'

ii) The condition of air entering the auditorium'

d) The amount of make uP air

rg ApParatus dew Point' and

v) By pass factor of the cooling coil'

Show the process on psychometric chart' t12I

Ql0)Write notes on any three of the following: [181

a) BYPass factor.

b) EffectivetemPerature'

c) Energy conservation in air-conditioning'

d) Duct sYstems.

e) Recirculated and ventilation air'

f...-

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ScatNo.

Ql)

B.E. (Mech.) (Semester - VIIf) Examination, May - 2014

POWER ENGINEERING (New) (Revised)

Sub. Code : 49419

Day and Datc : Tuesclay, 2CI-05-2014

Time : 2.30 pm to 5.30 pm

Instructions : 1) Solve any three questions from each section.

2) I'igures to thc right indicate full marks"

3) Assumc data if necessalT.

'Ibtal Marks : 100

SECTION - I

Discuss thc power generation in private sector in India.

Explain in brief the present power position in India and in Maharashtra.t8l

Compare thennal, Ilydraulic and Nuclear power plants with respect tovarious parameters.

An yearly load duration curve of a gas turbine powcr plant is a straightline fiom 45000 kw to 5000 kw. 'Ihe load is takcn by a power plantwhich consists of two units of 20000 kw each and onc unit of 10000 kw.Dctermine (i) load factor, (ii) capacity factor of plant.

Iixplain in brief the working principle of fuel ccll with suitable sketch.State its advantage.

'fhc maximum load on 2500 kw capacity diesel plant is 1600 kw J'hcload factor is 0.48. taking the following data, find out the cost ofgcncration in I{s. per kWh. Installation cost:Its. 1t100/kW; Intcrcst oncapital : 15Yo; Iluel cost :Rs. 7/kg; Maintenance cost : Rs. 200001yea1 'fotal labor and consumables cost: Rs. 85000lyear. Lubricating-oil

cost : Rs. 0.8/kg; Fuel consumed: O.25kglkwh; Oil consumcd:t8l

I2T,O.

a)

b)

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Q2) a)

b)

Q3) a)

b)

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Total No. of Pagcs : 2

0.025 kg/kwh.

w-63s[18]

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84) Write shorl notes on the followings (Any Three).

a) 'lher^mionic plant

b) Compressed air storage power plant

c) f)iesel engine powerplant

d) Combincd cycle power plant

SECTION . IIQS) a) tixplain the two methods to measure smoke and dust in the exhaust gas.[8]

b) What is pFI value? What is its impoftance flor feed r.vater used in powerplant? Iixplain any one method of pH measurement.

Q6) ") What is the function and components of Fuel Cell? Iixplain how cnergystorage is done by using fuel cell.

b) Describe with ncat skctch, thc principle, construction and working ofsuperconducting magnetic cncrgy storage device.

Q7) a) Describe thc different methodologies of power plant maintenance. t8l

b) Iixpiain thc different methods adopted to control the nuclear pollution? tSl

Q8) Writc short notes on the foiiowing. (1-tny T'hree).

a) 'I'hermal storage system.

b) I)osimetcr.

c) Nuclear radiation dctector.

d) Energy management techniques.

"ry.f.d

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