T.E. Sem V ICE ASSIGNMENT 1. Q.No. 1. Explain the following :- a) Assumption in Air-standered cycle b) Assumption in Fuel Air cycle c) Losses in actual cycle Q.No. 2. Differentiate beteween following :- a) SI Engine and CI Engine b) Four stroke engine and Two Stroke Engine Q.No.3. Define the following :- a) Break Power. b) Indicated Thermal Efficiency c) Volumeteric Efficiency d) Brake Thermal Efficiency. e) Indicated specific fuel consumption. f) Brake specific fuel consumption. g) Mean piston speed h) Specific power output i) Mean effective pressure Q.No.4. Draw the PV-diagram of 4-stroke & 2-stroke S.I. & C.I. engine & explain it. Q.No.5. Explain variable specific heat & its effects. ASSIGNMENT 2 Q.No.1. Define Carburator. Explain simple Carburator with neat sketch. Q.No.2. Why the air fuel mixture required under the following engine operating conditions are necessary for the carburated S.I.engine.Discuss in details with the suitable diagram & graph in support of your answer: a) A rich mixture is required at idealing and low load power range & with increasing load sudden acceleration. [Type text] Page 1
T.E. Sem V b) An economy mixture is required in cruising range with medium load. ASSIGNMENT 3 Q.No.1. In an Otto cycle air is at 15 0 C & 1.05 bar is compressed adiabatically untill the pressure is 13bar.Heat is added at constant volume until the pressure rise to 35 bar.calculate the air standard efficiency ;compression ratio & mean effective pressure for the cycle.take C v =0.718,R=0.287 Q.No.2. An amount of perfect gas has initial condition of volume 1m 3 pressure 1bar & the Temp. is 18 0 C.It undergoes ideal diesel cycle operation the pressure expansion during 0.1 m 3.Calculate the temperature at the measure points of cycle & evaluate the thermal efficiency of cycle.assume =1.4 for the gas. Q.No.3. An Oil engine takes air at 1.01 bar & 20 0 C & maximum cycle pressure is 69bar.The compression ratio is 18:1.Calculate the dual combustion cycle volume is equal to the head added at Const.pressure.Take C p =1.005,C v =0.718 & V=1.4 Q.No.4. A six cylinder 4-stroke petrol engine has a swept volume of 300cm 3 for cylinder a compression ratio of 10 & operate at speed of 3500 rpm.if the Otto cycle & that the pressure & temperature before isentropic compression are 1bar & 15 0 C respetively.take C v =0.718, =1.4 [Type text] Page 2
T.E. Sem V If the above equation is the C.I.engine operating on diesel cycle & receiving heat at the same rate.calculate the efficiency, the maximum temperature of the cycle,effective power output & the mean effective pressure. ASSIGNMENT 4 Q.No.1. A Morse test on a 12 cylinders 2-stroke C.I.engine of bore 40cm & stroke 50cm running at 200rpm gave the following reading: Condition Brake load(n) Condition Brake load(n) All firing 2040 7 th 1835 1 st cylinder 1830 8 th 1860 2 nd cylinder 1830 9 th 1820 3 rd cylinder 1850 10 th 1840 4 th cylinder 1830 11 th 1850 5 th cylinder 1840 12 th 1830 6 th cylinder 1855 All firing 2060 The output is found from the dynamometer using the relation : Bp=WN/180 where W is the brake load in Newton & N is the rpm.calculate the mechanical efficiency and B mep of the engine. Q.No.2. A six cylinder 4-stroke direct injection oil engine is to deliver 120KW at 1600 rpm.the fuel to be used has a calorific value of 43MJ/Kg & its percentage composition by mass is C=86%,H=13%,non-combustion=1%. The absolute volumetric efficency is assumed to 80% the indicated thermal efficiency 40% & the mechanical efficiency is 80%.The air consumption to be 110% in excess of that required for the correct combustion. 1) Estimate the volumetric composition of dry exhaust gas. [Type text] Page 3
T.E. Sem V 2) Determine the bore & stroke of the engine taking the stroke to bore ratio as 1.5.Assume the volume of 1kg of air at the given condition as 0.77m 3 oxygen in air is 23% by mass & 21% by volume. Q.No.3. A test on a two stroke engine gave the following result at full load: speed=350rpm,net brake load=65kg,mep=3bar,fuel consumption =4Kg/Hr.Jacket colling water flow rate =500Kg/hr,Jacket water temperature at inlet =20 0 C, Jacket water temperature at outlet =40 0 C,Test room temp. 20 0 C,Temperature of the exhaust gases=400 0 C,Air used per kg of fuel=32kg,cylinder dia.,=22 cm,stroke=28cm, effective brake dia.=1m,calorific value of fuel=43mj/kg,proporation of hydrogen in fuel =15%,Mean specific heat of dry exhaust gas=1kj/kgk,mean specific heat of steam=2.1 KJ/KgK.Sensible heat of water at room temp.=62kj/kg,latent heat of steam=2250kj/kg. Find IP,BP & draw up a heat balance sheet for the test in KJ/Min. & in percentage Q.No.4. In a test of Oil engine under full load condition the following result were obtained: IP=33KW,BP=27KW, Fuel used=8kg/hr, Rate of flow of water through gas calorimeter=12kg/min., calorific value of fuel=43mj/kg, inlet temp.of cooling water =15 0 C & outlet temp.,of cooling water =75 0 C,inlet temp. of water to exhaust gas calorimeter =15 0 C.outlet temp. of water to exhaust gas calorimeter =55 0 C.final temp.of the exhaust gases=80 0 C, Room temp.=17 0 C,Air fuel ratio on mass basis=20, mean specific heat of exhaust gas =1KJ/KgK,Specific heat of water=4.18kj/kgk,draw up a heat balance sheet & estimate the thermal & mechanical efficiency. [Type text] Page 4
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S.E. Sem V PRODUCTION PROCESS-II DESIGN OF JIGS & FIXTURE Q.1 Explain design principles common to Jigs & Fixtures Q.2 Compare a jig & a fixture. Explain 3-2-1 method of location in case of a Jig. Q.3 Explain the following (i)drill Bushes (ii)turning fixture (iii)use of tension & setting block in Milling fixture (iv)drill Jig METAL CUTTING AND TOOL ENGINEERING Q.1:-Clearly stating the assumption derive the relationship Merchant s original theory. 2Ø+β-ϓ= in Q.2:-Discuss the effect of cutting speed on various cost of machining. Derive an expression for optimum cutting speed and tool life for minimum cost. Q.03:-During machining of a steel with 7-α s -6-6-8-30-1mm (ASA) HSS tool the undeformed chip thickness of 0.18mm & a width of cut 2.5mm were used. The side rake angle α s of the tool was so chosen that the machining operation could be approximated to orthogonal cutting. The force components measured using a two component dynamometer were Tangential cutting force=1177 N, Thrust force=560 N Calculate (i)the side cutting rake angle (ii)the coefficient of friction on the rake face &(iii)the dynamic shear strength of work material. Q.04:-Determine the optimum cutting speed & tool life for an operation carried out on a lathe using the following information.(i)tool change time=4 mins (ii)tool regrind time=3 mins (iii) Machine running cost=20 paise per min Mr. T. Z. Quazi PP-II Page 1
S.E. Sem V (iv)depreciation of tool regrind=rs.1 The tool life equation is given by 60 T 0.2 =Constant Also find the number of components produced in a shift of 8 hours at the above condition. MEASUREMENT OF CUTTING FORCES Q.1:-What do you mean by Tool life? Explain effect of speed, feed, depth of cut, tool material &geometry on tool life. Q.2:-List out & explain the various types of tool wear mechanism. Q.3:-Write short notes on (i) Tool dynamometer (ii) Cutting tool material (iii) Cutting fluid (iv) Effects of various parameters on surface finish. Design of Cutting tools Q.1:-Explain with a neat sketch the orthogonal rake system(ors) of describing a single point cutting tool geometry. Q.2:-Explain various steps involved in the design of circular pull type broach with neat sketches. Q.3:-Draw a twist drill. Explain all the elements & angles of it. Also explain the effect of these on force & power. Q.4:-Explain design features of reamers with suitable sketches. Mr. T. Z. Quazi PP-II Page 2
S.E. Sem V SHEET METAL WORKING Q.01:-What factors should be considered for selecting an appropriate presses for a given job. Q.02:-Compare compound & Progressive dies. Q.03:-Explain the following. (i) Types of Bending dies. (ii) Methods of Reducing spring back in bending. (iii) Operations performed on presses. (iv) Methods of reducing cutting forces in punches. Q.04: Design & sketch blanking die for producing about 3000 pcs/month.the plate is round in shape having diameter of 60mm.The material is 3mm thick M.S.sheet having shear strength of 430N/mm 2 & tensile strength of 600 N/mm 2.Assume suitable data whenever necessary. Q.01:-Explain the following ROLLING & FORMING OF METAL (i) Torque & Power calculation in Rolling (ii)thread Rolling (iii)extrusion (iv) Types of Rolling Mills (v) Forging Mr. T. Z. Quazi PP-II Page 3
-Kharghar T. E. Sem V [Year] THEORY OF MACHINE-II Assignment No.01 CLUTCH Q.1 Classify the different types of clutches. Q.2 Describe the construction and working of cone clutch. Q.3 Derive an expression for frictional torque for a cone clutch, considering uniform pressure. Q.4 A single plate clutch, effective on both sides, is required to transmit 25 Kw at 3000 rpm. Determine the outer and inner raddi of frictional surface if the coefficient of friction is 0.255, the ration of raddi is1.25 and the maximum pressure is not to exceed 0.1 N/mm2.Also determine the axial thrust to be provided by springs. Assume the theory of uniform wear. Q.5 A centrifugal clutch has four shoes which slides radially in a spider keyed to the driving shaft and make contact with the internal cylindrical surface of a rim keyed to the driven shaft. When the clutch is at rest, each shoe is pulled against a stop by a spring so as to leave a radial clearance of 5 mm between the shoe and the rim. The pull exerted by the spring is 500 N. The mass centre of the shoe is 160 mm from the axis of the clutch. If the internal diameter of the rim is 400 mm, the mass of each shoe is 8 Kg, the stiffness of each spring is 50 N/mm and the coefficient of friction between the shoe and the rim is 0.3, find the power transmitted by the clutch at 500 rpm. Assignment No.2 BREAKS AND DYNAMOMETERS Q.1 Explain the different types of brakes? Q. 2 Describe with the help of a neat sketch the principle of an internal expanding shoe. Derive the expression for the braking torque. Q.3 Classify the different types of dynamometers, and explain. Mr. M.Jagtap TOM-II 1
-Kharghar T. E. Sem V [Year] Q.4 Derive an expression for four wheeled moving vehicle, the brakes may be applied to i) The four wheels only ii) The front wheel only iii) All the four wheels Q.5 In a band and block brakes, having 14 blocks each of which subtends an angle of 15 0 at the centre, is applied to a drum of 1 m effective diameter. The drum and flywheel mounted on same shaft has a mass of 2000 Kg and a combined radius of gyration of 500 mm. The two ends of the bands are attached to pins on opposite sides of the brake liver at a distance of 30 mm and 120 mm from the fulcrum. If a force of 200 N is applied at a distance of 750 mm from the fulcrum, find i) Maximum braking torque ii) Angular retardation of the drum and, iii) Time taken by the system to come to rest from the rated speed of 360 rpm. The coefficient Of friction between the blocks and the drum may be taken as 0.25. Assignment No.3 GOVERNORS Q.1 State the different types of governors. What is the difference between centrifugal and inertia governors? Why is the former preferred to the latter? Q.2 Define and explain the following term related to governors a) Stability b) Sensitiveness c) Isochronisms d) Hunting. Q.3 Discuss the controlling force and stability of a governor and show that the stability of a governor depends on the slope of the curve connecting the controlling force (Fc ) and radius of rotation (r) and the value (Fc /r). Q.4 A portal governor has equal arms 200 mm long pivoted on the axis of rotation. The mass of each ball is 3 Kg and the mass of the sleeve is 15 Kg. The ball path is 120 mm when the governor begins to lift and 160 mm at the maximum speed. Determine the range of speed. If the friction at the sleeve is equivalent to a force of 10 N, find the coefficient of insensitiveness. Mr. M.Jagtap TOM-II 2
-Kharghar T. E. Sem V [Year] Q.5. In a spring controlled governor, the curve of controlling force is a straight line. When balls are 400 mm apart, the controlling force is 1200 N and when 200 mm apart, the controlling force is 450 N. At what speed will the governor run when the balls are 250 mm apart. What initial tension on the spring would be required for isochronisms and what would then be the speed. The mass of each ball is 9 Kg. Assignment No.04 GYROSCOPE Q.1 Derive an expression for gyroscopic couple. Q.2 Explain how a governor and flywheel are different as far as their working principle and applications are concerned. Q.3 The radius of gyration of a turbine rotor in a ship with a mass of 20,000 Kg is 50 cm the rotor rotates at a speed of 2000 rpm. In a clockwise direction when viewed from the stern of the ship. The ship pitches with total angle of 150.The motion can be considered to be a simple harmonic motion with equal deviation on both sides of the axis of spin with a time period of 15 seconds. Calculate the maximum gyroscopic couple on the bolt of the turbine and the direction of steering as the bow rises. Q.4 What is the effect of stability of a four wheeled drive moving in a curved path? Q.5 A four wheeled trolly car of total mass 2000 Kg running on rails of 1.6 m gauge, round a curve of 30 m radius at 54 km/hr. The track is backed at 8 o.the wheel have an external dia. Of 0.7 m and each pair with axle has a mass of 200 Kg. The radius of gyration for each pair is 0.3 m. The height of centre of gravity of the car above the wheel base is 1 m. Determine, allowing for centrifugal force and gyroscopic couple actions, the pressure on each rail. Assignment No.05 GEAR TRAINS Q.1 What do you understand by gear train? Discuss the various types of gear trains. Q.2 Explain with neat sketch the sun and planet wheel. Q.3 What are the various types of the torques in an epicyclic gear train? Mr. M.Jagtap TOM-II 3
-Kharghar T. E. Sem V [Year] Q.4 Arrange 4 gears of the same module with number of teeth as 20, 30, 50, and 75 to form a compound gear train, to have maximum retardation ration. Draw a neat schematic diagram of the compound train you have chosen. Q.5 In a reverted epicyclic gear train, the arm A carries two gears B and C and a compound gear D-E. The gear B meshes with gear E and gear C meshes with gear D. The number of teeth on gears B, C and D are 75, 30, and 90 resp. Find the speed and direction of gear C when gear B is fixed and the arm A makes 100 rpm clockwise. Assignment No.06 CAM AND FOLLOWER Q.1 Classify the different types of cam and follower, with neat sketch, also explain the terminology of cam. Q.2 The following data refers to a cam operating a vertical spindle. (i) Lift of the follower = 40 mm (ii) Angle of ascent = 90 0 (iii) Angle of descent = 120 0 (iv) Angle of dwell between ascent and descent = 60 0 (v) Motion of the follower during ascent: cycloidal (vi) Motion of the follower during descent: SHM Draw the displacement, velocity, acceleration and jump curves. Show clearly the values of maximum velocity and maximum acceleration above and below the reference line of your diagrams. Q.3 what do you mean by pressure angle with respect to cam and follower mechanism? What is its significance? Q.4 What are the different types of motions of the followers? Q.5 The following data refers to a. (i) Lift of the follower = 50 mm (ii) Angle of ascent = 90 0 (iii) Angle of descent = 100 0 Mr. M.Jagtap TOM-II 4
-Kharghar T. E. Sem V [Year] (iv) Angle of dwell between ascent and descent = 60 0 (v) Motion of the follower during ascent: uniform acceleration and retardation (vi) Motion of the follower during descent: uniform velocity Draw the displacement, velocity, acceleration and jump curves. Show clearly the values of maximum velocity and maximum acceleration above and below the reference line of your diagrams. Mr. M.Jagtap TOM-II 5