DESIGN OF MACHINE MEMBERS-II

Transcription

1 Set No. 1 Code No: R32035 R10 DESIGN OF MACHINE MEMBERS-II Time: 3 hours Max. Marks: 75. All Questions carry equal marks (Data books may be allowed) 1 a) Explain about classification of bearings. 5 b) A rolling contact bearing is subjected to the following work cycle: (a) Radial load of 6000 N at 150 r.p.m. for 25% of the time; (b) Radial load of 7500 N at 600 r.p.m. for 20% of the time; and (c) Radial load of 2000 N at 300 r.p.m. for 55% of the time. The inner ring rotates and loads are steady. Select a bearing for an expected average life of 2500 hours. 2 a) Explain the various stresses induced in the connecting rod. 5 b) Design a plain carbon steel centre crankshaft for a single acting four stroke single cylinder engine for the following data: Bore = 400 mm ; Stroke = 600 mm ; Engine speed = 200 r.p.m.; Mean effective pressure = 0.5 N/mm 2 ; Maximum combustion pressure = 2.5 N/mm 2 ; Weight of flywheel used as a pulley = 50 kn; Total belt pull = 6.5 kn. When the crank has turned through 35 from the top dead centre, the pressure on the piston is 1N/mm 2 and the torque on the crank is maximum. The ratio of the connecting rod length to the crank radius is 5. Assume any other data required for the design. 3 a) State the function of the following for an internal combustion engine piston: (a) Ribs ; (b) Piston rings ; (c) Piston skirt ; and (d) Piston pin b) A four stroke internal combustion engine has the following specifications: Brake power = 7.5 kw; Speed = 1000 r.p.m.; Indicated mean effective pressure = 0.35 N/mm 2 ; Maximum gas pressure = 3.5 N/mm 2 ; Mechanical efficiency = 80 %. Determine: 1) The dimensions of the cylinder, if the length of stroke is 1.4 times the bore of the cylinder; 2) Wall thickness of the cylinder, if the hoop stress is 35 MPa; 3) Thickness of the cylinder head and the size of studs when the permissible stresses for the cylinder head and stud materials are 45 MPa and 65 MPa respectively. 4 a) Derive the expression for h 2 for rectangular section. 6 b) A central horizontal section of a hook is symmetrical trapezium 90mm deep. The inner width being 90mm and outer being 45mm. The hook carries a load of 67.5KN the load line passes at a distance of 40mm from the inside edge of the section. The centre of curvature is in the load line. Calculate the extreme intensities of stress. Also plot the stress distribution across the section. 5 a) Why belts are provided with initial tension? Why slip is necessary is less in V-belt compared with flat belt? b) Design a wire rope for a lift which is to be used for maximum 100 KN for a building with a height of 400 m. The lift will attain a speed of 100 m/min in 6 sec. Assume load factor of of 2

2 Set No. 1 Code No: R32035 R10 6 Pair of helical gear with 17 teeth and 51 teeth of pinion and gear respectively transmits 2.5 KW power at 1750 rpm of the pinion. The normal pressure angle and helix angle are 20 0 and 23 0 respectively. The normal module and normal face width are 2 mm and 25 mm respectively. The gear and pinion are made from hardened steel. The surface and core hardness of pinion is 240 BHN and of gear 200 BHN. If expected pinion life is more than 10 8 cycles at 99% reliability find (a) the factor of safety in bending and (b) the factor of safety in wear. 7 a) How does the helix angle influence on the efficiency of square threaded screw? What do you understand by overhauling of screw? b) A vertical square threads screw of a 70 mm mean diameter and 10 mm pitch supports a vertical load of 50 kn. It passes through the boss of a spur gear wheel of 70 teeth which acts as a nut. In order to raise the load, the spur gear wheel is turned by means of a pinion having 20 teeth. The mechanical efficiency of pinion and gear wheel drive is 90%. The axial thrust on the screw is taken up by a collar bearing having a mean radius of 100 mm. The coefficient of friction for the screw and nut is 0.15 and that for collar bearing is Find (a) Torque to be applied to the pinion shaft, (b) Maximum principal and shear stresses in the screw and (c) Height of nut, if the bearing pressure is limited to 12 N/mm 2. 8 a) What do you understand by leverage? Why levers are usually tapered? 5 b) Design a cranked lever to be operated by two persons. The maximum lever arm length is 500 mm. The lever arm is made of 40C8 steel with ultimate stress of 580 MPa, yield stress of 380 MPa. Take a factor of safety of 5 for ultimate strength and 2.5 for yield strength of

3 Set No. 2 Code No: R32035 R10 DESIGN OF MACHINE MEMBERS-II Time: 3 hours Max. Marks: 75. All Questions carry equal marks (Data books may be allowed) 1 a) Define the following terms as applied to rolling contact bearings:(a) Basic static load 5 rating (b) Static equivalent load (c) Basic dynamic load rating b) A full journal bearing of 50 mm diameter and 100 mm long has a bearing pressure of 1.4 N/mm 2. The speed of the journal is 900 r.p.m. and the ratio of journal diameter to the diametral clearance is The bearing is lubricated with oil whose absolute viscosity at the operating temperature of 75 C may be taken as kg/m-s. The room temperature is 35 C. Find : 1. The amount of artificial cooling required, and 2. The mass of the lubricating oil required, if the difference between the outlet and inlet temperature of the oil is 10 C. Take specific heat of the oil as 1850 J / kg / C Determine the dimensions of an I-section connecting rod for a petrol engine from the following data: Diameter of the piston = 110 mm; Mass of the reciprocating parts = 2 kg; Length of the connecting rod from centre to centre = 325 mm; Stroke length = 150 mm; R.P.M. = 1500 with possible overspeed of 2500; Compression ratio = 4 : 1; Maximum explosion pressure = 2.5 N/mm 2. 3 a) Explain the various types of cylinder liners. 5 b) A four stroke diesel engine has the following specifications: Brake power = 5 kw; Speed = 1200 r.p.m. ; Indicated mean effective pressure = 0.35 N / mm 2 ; Mechanical efficiency = 80 %. Determine: 1) bore and length of the cylinder; 2) thickness of the cylinder head and 3) size of studs for the cylinder head. 4 Determine (i) location of neutral axis, (ii) maximum and minimum stresses when a curved beam of trapezoidal section of bottom width 30 mm, top width 20 mm and height 40 mm is subjected to pure bending moment of Nm. The bottom width is towards the centre of curvature. The radius of curvature is 50 mm and beam is curved in a plane parallel to depth. Also plot the variation of stresses across the section. 5 a) State the advantages and disadvantages of the chain drive over belt and rope drive. 5 b) Determine the percentage increase in power capacity made possible in changing over from a flat belt drive to a V-belt drive. The diameter of the flat pulley is same as the pitch diameter of the grooved pulley. The pulley rotates at the same speed as the grooved pulley. The coefficient of friction for the grooved and flat belt is same and is 0.3. The V- belt pulley groove angle is 60. The belts are of the same material and have same crosssectional area. In each case, the angle of wrap is of 2

4 Set No. 2 Code No: R32035 R10 6 A pair of 20 full-depth involute tooth spur gears is to transmit 30 kw at a speed of 250 r.p.m. of the pinion. The velocity ratio is 1 : 4. The pinion is made of cast steel having an allowable static stress, 100 MPa, while the gear is made of cast iron having allowable static stress, 55 MPa. The pinion has 20 teeth and its face width is 12.5 times the module. Determine the module, face width and pitch diameters of both the pinion and gear from the standpoint of strength only taking velocity factor into consideration. Assume suitable values of velocity factor and Lewis factor. 7 a) What is self locking property of threads and where it is necessary? 5 b) Design a screw jack for lifting a load of 50 kn through a height of 0.4 m. The screw is made of steel and nut of bronze. The following allowable stresses may be assumed. For steel : Compressive stress = 80 MPa ; Shear stress = 45 MPa For bronze: Tensile stress = 40 MPa ; Bearing stress = 15 MPa, Shear stress = 25 MPa. The coefficient of friction between the steel and bronze pair is The dimensions of the swivel base may be assumed proportionately. The screw should have square threads. Design the screw, nut. 8 Design a lever for a safety valve. The lever loaded safety valve exerted a force of 3 KN on the lever. The distance between the fulcrum and dead weight is 1000 mm. The distance between fulcrum and the pin connecting the valve spindle to the lever is 200 mm. Assuming the lever material as steel having ultimate strength of 380 MPa, determine the dimensions. Take factor of safety as 4. The bearing pressure is 20 MPa. 2 of

5 Set No. 3 Code No: R32035 R10 DESIGN OF MACHINE MEMBERS-II Time: 3 hours Max. Marks: 75. All Questions carry equal marks (Data books may be allowed) 1 a) State any four objectives of lubrication. Give the factors that form and maintain thick 6 oil film in hydrodynamic journal bearings. b) Following data refer to a hydrodynamic journal bearing Load = 3.2 kn, speed = 1490 rpm, diameter = 50 mm, length = 50 mm, radial clearance = 0.05 mm, Viscosity = 25 cp. Assume heat generated is carried away by oil flow. Calculate coefficient of friction, power lost in friction, minimum oil film thickness, flow and temperature rise. 9 2 Design a plain carbon steel centre crank shaft for single acting four stroke single cylinder engine for the following specifications. Bore = 140 mm, stroke = 200 mm, mean effective pressure = 1.02 MPa, maximum combustion pressure = 3.5 MPa, weight of the flywheel = 2800 N, total belt pull = 4 KN, engine speed = 300 rpm when the crank has turned 30 0 from the top dead centre the pressure on the piston is 1.25 MPa and the torque is maximum. Assume any other data and design the crankshaft. 3 Design a cast iron piston for a four stroke single cylinder semi diesel engine running at 700 rpm. The maximum explosion pressure on the cylinder head is about 4 MPa. The mean effective pressure is about 0.75 MPa. The diameter and the stroke of the piston are 250 mm and 375 mm respectively. The connecting rod length is 700 mm. The piston is to have at least 3 sealing rings and two oil rings. Heat conducted through the piston crown is approximately 4.5 to 5% of the tol heat produced. The temperature at the centre and edges may be assumed as C and C respectively. 4 a) What are the assumptions made in derivation of stresses in a curved bar which is subjected to bending moments. 5 b) Derive the expression for Winkler-Bach formula a) State the advantages and disadvantages of the chain drive over belt and rope drive. 4 b) An exhaust fan fitted with 900 mm diameter pulley is driven by a flat belt from a 30 kw, 950 r.p.m. squirrel cage motor. The pulley on the motor shaft is 250 mm in diameter and the centre distance between the fan and motor is 2.25 m. The belt is 100 mm wide with a coefficient of friction of If the allowable stress in the belt material is not to exceed 2 MPa, determine the necessary thickness of the belt and its total length. Take centrifugal force effect into consideration for density of belt being 950 kg/m 3. 1 of

6 Set No. 3 Code No: R32035 R10 6 a) What is a herringbone gear? List the assumptions made in Lewis equation. 5 b) The following data is given for a spur gear. Number of teeth on pinion = 30, number of teeth on gear = 60, speed of pinion = 1440 rpm, pressure angle = 20 0 involute type, module = 3 mm, face width = 32 mm, both gears are made of steel with ultimate strength 560 MPa. Determine (a) the rated power on the basis of bending failure if the factor of safety is 1.5, (b) the factor of safety on the basis of dynamic failure. 7 a) In what way the power screws differ from threaded fasteners? Which thread forms are used for power screw? Why? b) Design a screw jack to lift a maximum load of 50 KN through a height of 200 mm with ground clearance of 300 mm. The allowable bearing pressure between nut and screw is 16 N/mm 2. The coefficient of friction of threads and collars may be taken as Select the suitable material and stresses. Assume the data wherever necessary. 8 Design a cranked lever to be operated by two persons. The maximum lever arm length is 500 mm. The lever arm is made of 40C8 steel with ultimate stress of 580 MPa, yield stress of 380 MPa. Take a factor of safety of 5 for ultimate strength and 2.5 for yield strength. 2 of

7 Set No. 4 Code No: R32035 R10 DESIGN OF MACHINE MEMBERS-II Time: 3 hours Max. Marks: 75. All Questions carry equal marks (Data books may be allowed) 1 a) State the types of journal bearing failure 4 b) Following data refer to a hydrodynamic journal bearing radial load = 10 kn, journal speed = 1440 rpm, unit bearing pressure = 900 kpa, clearance ratio = 800, lubricant viscosity = 30 Ns/m 2. Assuming that total heat generated in the bearing is carried by the total oil flow in the bearing, determine (i) dimensions of bearing (ii) coefficient of friction (iii) power lost in friction (iv) total oil flow (v) side leakage (vi) temperature 2 Design a connecting rod for four stroke petrol engine with the following data Piston diameter = 0.10 m, stroke = 0.14 m, length of the connecting rod from centre to centre = m weight of reciprocating parts = 18.2 N speed = 1500 rpm with possible over speed of 2500 compression ratio = 4:1 probable maximum explosion pressure = MPa. 3 Design an aluminum alloy trunk type piston for a single acting two stroke engine for 15 the following specifications. Cylinder bore = 75 mm, stroke = 100mm, maximum gas pressure = 4 MPa, break mean effective pressure = 0.9 MPa, fuel consumption = 0.2 kg/kw/h, speed = 900 rpm. Assume any other data if required. 4 a) Derive the expression for h 2 for trapezoidal section. 6 b) Determine the location of neutral axis, minimum and maximum stresses, ratio of minimum and maximum stress when a curved beam of rectangular section of width 10mm and depth 20mm is subjected to pure bending moment +50Nm. The beam is curved in a plane parallel to the depth. The mean radius of curvature is 25mm. Also plot the variation of stresses across the section. 5 a) How do you classify wire rope? List the advantages of rope drive over belt drive 4 b) A V-belt is to transmit 14.7 KW to a compressor. The motor speed is 1150 rpm and the compressor pulley runs at 400 rpm. Determine the size and number of belts required. 6 a) Explain the different causes of gear tooth failures and suggest possible remedies to avoid such failures. b) A spur gear made of bronze drives a mid steel pinion with angular velocity ratio of 3.5. The pressure angle is It transmits 5 kw at 1800 r.p.m. of pinion. Considering only strength, design the smallest diameter gears and find also necessary face width. The number of teeth should not be less than 15 teeth on either gear. The elastic strength of bronze may be taken as 84 MPa and of steel as 105MPa. Lewis factor for 14.5 pressure angle may be taken as y =0.124 (0.684/No. of teeth) 1 of

8 Set No. 4 Code No: R32035 R10 7 a) What are differential and compound screws? Explain with sketches. What advantages are offered by them? b) The lead screw of a lathe has ACME threads of 50 mm outside diameter and 8 mm pitch. The screw must exert an axial pressure of 2500 N in order to drive the tool carriage. The thrust is carried on a collar 110 mm outside diameter and 55 mm inside diameter and the lead screw rotates at 30 rpm. Determine the power required to drive the screw. Assume the coefficient of friction of 0.15 for screw and 0.12 for the collar. 8 Design a lever for a safety valve. The lever loaded safety valve exerted a force of 3 KN on the lever. The distance between the fulcrum and dead weight is 1000 mm. The distance between fulcrum and the pin connecting the valve spindle to the lever is 200 mm. Assuming the lever material as steel having ultimate strength of 380 MPa, determine the dimensions. Take factor of safety as 4. The bearing pressure is 20 MPa. 2 of

9 Set No. 1 Code No:R32033 R10 HEAT TRANSFER Time: 3 hours Max. Marks:75 All Questions carry equal marks 1 a) Define the following: i) Thermal conductivity ii) Convection heat transfer coefficient iii) Radiation heat transfer Coefficient and iv) overall heat transfer coefficient. b) An immersion water heater of surface area 0.1m 2 and rating 1kW is designed to operate fully submerged in water. Estimate the surface temperature of the heater when the water is at 40 C and the heat transfer coefficient is 300 W/m 2 K. If this heater is by mistake used in air at 40 C with h = 9 W/m 2 K, what will be its surface temperature? 2 a) What is critical thickness of insulation on a small diameter wire or pipe. Explain its physical significance? b) A cylinder 1 m long and 5 cm in diameter is placed in an atmosphere at 45 C. It is provided with 10 longitudinal straight fins of material having k = 120 W/mK. The height of 0.76 mm thick fins is 1.27 cm from the cylinder surface. The heat transfer coefficient between cylinder and atmospheric air is 17 W/m 2 K. Calculate the rate of heat transfer and the temperature at the end of fins if surface temperature of cylinder is 150 C. 3 a) What are Biot and Fourier numbers? Explain their physical significance? b) A stainless steel rod of outer diameter 1cm originally at a temperature of 320 C is suddenly immersed in a liquid at 120 C for which the convective heat transfer coefficient is 100 W/m 2 K. Determine the time required for the rod to reach a temperature of 200 C? 4 a) Define Reynolds, Nusselt, Prandtl and Stanton numbers. Explain their importance in convective heat transfer? b) Calculate the pressure drop in 100m of 2cm x 2.5 cm smooth rectangular duct when water at 40 C flows through it with a velocity of 0.5 m/s. (v = 0.66 x 10-6 m 2 /s, ρ = 995 kg/m 3 ) 5 a) What is the criterion for transition from laminar to turbulent flow in free convection heat transfer? b) Determine the rate of heat loss per meter length from a 10 cm outside diameter steam pipe place horizontally in ambient air at 30 C. The pipe has an outside wall temperature of 170 C and in emissivity of of 2

10 Set No. 1 Code No:R32033 R10 6 a) Write a brief note on heat transfer during boiling and condensation? b) Dry saturated steam at a pressure of 2.45 bar condenses on the surface of a vertical tube of height 1 m. The tube surface temperature is kept at 117 C. Estimate the thickness of the condensate film and the local heat transfer coefficient at a distance of 0.2 m from the upper end of the tube? 7 a) How are heat exchangers classified? Why is a counter flow heat exchanger more efficient than a parallel flow exchanger? b) Hot oil with a capacity rate of 2500 W/K flows through a double pipe heat exchanger. It enters at 360 C and leaves at 300 C. Cold fluid enters at 30 C and leaves at 200 C. If the overall heat transfer coefficient is 800 W/m 2 K, determine the heat exchanger area required for (i) Parallel flow and (ii) Counter flow. 8 a) What is the Stefan-Boltzmann Law? Explain the concept of total emissive power of a surface? b) The surfaces of a double-walled spherical vessel used for storing liquid oxygen are covered with a layer of silver having an emissivity of The temperature of the outer surface of the inner wall is -153 C and the temperature of the inner surface of the outer wall is 27 C. The spheres are 42 cm and 60 cm in diameter, with the space between them evacuated. Calculate the radiation heat transfer through the walls into the vessel and the rate of the evaporation of liquid oxygen if its rate vaporization is 220 kj/kg. 2 of 2

11 R10 Code No:R32033 Set No. 2 HEAT TRANSFER Time: 3 hours Max. Marks:75 All Questions carry equal marks 1 a) Describe the mechanism of (i) Heat Convection (ii) Mass diffusion (iii)heat conduction in solids b) A hot plate of length 0.75m, width 0.5m and thickness 2cm is placed in air stream at 20 C. It is estimated that a total of 300W is lost from the plate surface by radiation. Taking the convective heat transfer coefficient as 25 W/m2K, and the thermal conductivity of the plate as 43 W/mK, calculate the inside temperature of the plate? 2 a) Sketch various types of fin configurations b) Compare the efficiency of a plate in of length L = 1.5 cm and thickness 2.0 mm for the following two cases: (i) Fin material is aluminium (k= 210 W/mK) and the heat transfer coefficient is 285 W/m 2 K. (ii) Fin material is steel (k = 40 W/mK) and h = 510 W/m 2 K. 3 Aluminium sphere weighing 5.5 kg and initially at a temperature of 290 C is suddenly immersed in a fluid at 15 C. The convective heat transfer coefficient 58 W/m 2 K. Estimate the time required to cool the aluminium to 95 C, using the lumped capacity method of analysis. 4 a) What is the Prandtl number? Show that it is a dimensionless quantity. b) Liquid sodium is to be heated from 120 C to 149 C at a rate of 2.3 kg/s in a 2.5cm diameter electrically heated tube (constant heat flux). Calculate the minimum length of the tube if its wall temperature is not to exceed 200 C. 5 a) Sketch temperature and velocity profiles in free convection on a vertical wall. b) Calculate the coefficient of heat transfer by free convection between a horizontal wire and air at 25 C. The surface of the wire is at 95 C and if diameter is 2.5 mm. Also find the maximum admissible current intensity if the resistance of the wire is 6 ohm/m. 1 of 2

12 Set No. 2 Code No: R32033 R10 6 a) Distinguish between film wise and drop wise condensation. Which of the two does give a higher heat transfer coefficient? Why? b) A vertical tube of 50 mm outside diameter and 2 m long is exposed to steam at atmospheric pressure. The outer surface of the tube is maintained at a temperature of 84 C by circulating cold water through the tube. Determine the rate of heat transfer and also the condensate mass flow rate. 7 a) Explain how the heat exchangers are classified. b) Saturated steam at 100 C is condensing on the shell side of a shell-and-tube heat exchanger. The cooling water enters the tubes at 30 C and leaves at 70 C. Calculate the effective log mean temperature difference if the arrangement is (i) counter flow, (ii) parallel flow and (iii) cross flow. 8 a) State and prove Kirchhoff s law of radiation? b) A pipe carrying steam having and outside diameter of 20 cm runs in a large room and is exposed to air at a temperature of 30 C. The pipe surface temperature is 400 C. I. Calculate the loss of heat to surroundings per meter length of pipe due to thermal radiation. The emissivity of the pipe surface is 0.8. II. What would be the loss of heat due to radiation if the pipe is enclosed in a 40 cm diameter brick conduit of emissivity 0.91? 2 of 2

13 Set No. 3 Code No: R32033 R10 HEAT TRANSFER Time: 3 hours Max. Marks:75 All Questions carry equal marks 1 a) Derive differential equation of heat conduction in Cartesian coordinate system? b) A constant temperature difference of 166.7ºC is maintained across the surfaces of slab of 3.05 cm thickness. Calculate the rate of heat transfer per unit area across the slab for each of the following cases: (i) Slab is made copper of k = W/mK. (ii) Slab is made of Aluminiumof k= 225 W/mK (iii) Slab is made of carbon steel of k = 17.3 W/mK. (iv) Slab is made of brick of k = W/mK. (v) Slab is made of asbestos of k = W/mK. 2 a) What is critical thickness of insulation on a small diameter wire or pipe? Explain its physical significance and derive an expression for the same? b) In an experiment to determine the thermal conductivity of a long solid 2.5 cm diameter rod, its base is placed in a furnace with a large portion of it projecting into the room air at 22 ºC. After steady state conditions prevail, the temperatures at two points, 10 cm apart, are found to be 120 ºC and 85 ºC respectively. The convective heat transfer coefficient between the rod surface and the surrounding air is 28.4 W/m 2 K. Determine the thermal conductivity of the rod material? 3 a) Explain why Heisler Charts cannot be used for the case of Biot number approaching zero. What is the alternative for solving this typical case? b) A stainless steel rod of outer diameter 1 cm originally at a temperature of 320 ºC is suddenly immersed in a liquid at 120 ºC for which the convective heat transfer coefficient is 100 W/m 2 K. Determine the time required for the rod to reach a temperature of 200 ºC? 4 a) State the Buckingham s π Theorem. Explain the various parameters used in forced convection. Using dimensional analysis obtain an expression for Nusselt number in terms of Reynolds and Prandtl numbers? b) Water flows through a tube of 2 cm I.D. at a rate of 1.5 liters per minute. Taking the kinematic viscosity of water as 1 x 10-6 m 2 /s. Determine whether the flow is laminar or turbulent. Also estimate the entry length. 1 of 2

14 Set No. 3 Code No: R32033 R10 5 a) Compare the variations of velocity, temperature and local heat transfer coefficient along a vertical plate for the plate under natural convection and force convection? b) A flow through a long rectangular (30 cm height x 60 cm width) air conditioning duct maintains the outer duct surface temperature at 15ºC. If the duct is uninsulated and exposed to air at 25 ºC, calculate the heat gained by the duct per metre length, assuming it to be horizontal? 6 a) Describe in some detail the process of nucleate boiling and give one form of equation frequently used? b) A vertical tube of 50 mm outside diameter and 2 m long is exposed to steam at atmospheric pressure. The outer of the tube is maintained at a temperature of 84 ºC by circulating cold water through the tube. Determine the rate of heat transfer and also the condensate mass flow rate? 7 a) Sketch the temperature variations in parallel flow and counter heat exchangers? b) A counter flow concentric tube heat exchanger is used to cool engine oil (c = 2130 J/kg.K) from 160 ºC to 60 ºC with water, available at 25 ºC as the cooling medium. The flow rate of cooling water through the inner tube of 0.5 m diameter is 2 kg/s while the flow rate of oil through the outer annulus O.D = 0.7 m is also 2 kg/s. If the value of the overall heat transfer coefficient is 250 W/m 2.K, how long must the heat exchanger be to meet its cooling requirement? 8 a) What is the Stefan-Boltzmann Law? Explain the concept of total emissive power of a surface? b) Assuming the sun to be a black body at a temperature of 5700 ºC. Calculate, (i) The emissive power of the surface of the sun? (ii) Wavelength for maximum spectral intensity? (iii) Heat energy imitate by the sun per unit time assuming its diameter as x 109 m. 2 of 2

15 Set No. 4 Code No: R32033 R10 HEAT TRANSFER Time: 3 hours Max. Marks:75 All Questions carry equal marks 1 a) Derive differential equation of heat conduction in cylindrical coordinate system? b) A hot plate of length 0.75 m, width 0.5m, and thickness 2 cm is place in air stream at 20ºC. It is estimated that a total of 300 W is lost from the plate surface by radiation. Taking the convective heat transfer coefficient as 25 W/m 2 K, and thermal conductivity of the plate as 43 W/mK, calculate the inside temperature of the plate? 2 a) Derive the expression for efficiency and effectiveness of rectangular fins. b) Triangular fins 2.5 cm thickness at base and 10 cm long and made from stainless steel (k = 17.7 W/mK and ρ = 7850 kg/m3) are to be fitted to an air cooled cylinder wall. If the wall the temperature is 6 ºC and the heat transfer coefficient between the solid surface and air (T = 40 ºC) is 20 W/m2K, derive an expression for temperature distribution along the fin. Also estimate the rate of heat flow per unit mass of the fin? 3 a) Determine thermal diffusivity. Explain its significance in terms of penetration depth for a semi-infinite body. b) A slab of aluminium 10 cm thick is originally in a temperature of 500 ºC. It is suddenly immersed in a liquid at 100 ºC resulting in a heat transfer coefficient of 1200 W/m 2 K. Determine the temperature at the center line and the surface 1 minute after the immersion. Also calculate the total thermal energy removed per unit area of the slab during this period. The properties of aluminium for the given conditions are α = 8.4 x 10-5 m 2 /s k = 215 W/mK ρ = 2700 kg/m 3 c = 0.9 kj/kg/k 4 a) What is Prandtl number? Show that it is a dimensionless quantity. b) A 30 cm long glass plate is hung vertically in the air at 27 ºC while its temperature is maintained at 77 ºC. Calculate the boundary layer thickness at the trailing edge of the plate. If a similar plate is place in a wind tunnel and air is blown over it at a velocity of 4 m/s, estimate the boundary layer thickness at its trailing edge? 1 of 2

16 Set No. 4 Code No: R32033 R10 5 a) Using dimensional analysis establish a relation between Nuselt, Prandtl and Grashof number? b) A 30 cm long glass plate is hung vertically in the air at 27 ºC while its temperature is maintained at 77 ºC. Calculate the boundary layer thickness at the trailing edge of the plate. If a similar plate is place in a wind tunnel and air is blown over it at a velocity of 4 m/s, estimate the boundary layer thickness at its trailing edge? 6 a) Distinguish between filmwise and dropwise condensation. Which of the two gives a higher heat transfer coefficient? Why? b) Determine the stable film boiling heat transfer coefficient for the film boiling of saturated water at atmospheric pressure on an electrically heated 1.6 mm diameter horizontal platinum wire with a temperature difference T s T sat = 225 ºC. What would be power dissipation per unit length of the heater? 7 a) Discuss the general arrangement of parallel flow, counter flow and cross flow heat exchangers? And why a counter flow heat exchanger more effective than a parallel flow exchanger? b) Water enters a counter flow, double pipe heat exchanges at 15 ºC, flowing at the rate of 1300 kg/h. It is heated by oil (Cp = 2 J/kg.K) flowing at the rate of 550 kg/h from the inlet temperature of 94 ºC. For an area of 1 m 2 an overall heat transfer coefficient of 1075 W/m 2.K, determine the total heat transfer and the outlet temperatures of water and oil? 8 a) Distinguish between (i) A black body and gray body (ii) Specular and diffuse surfaces (iii) Absorptivity and emissivity of a surface (iv) Total emissivity and equilibrium emissivity b) A pipe carrying steam having an outside diameter 20 cm runs in a large room, and is exposed to air at a temperature of 30 ºC. The pipe surface temperature is 200 ºC. Find the heat loss per metre length of the pipe by convection and radiation taking the emissivity of the pipe surface as of 2

17 Set No. 1 Code No: R32036 R10 III B.Tech II Semester Regular Examinations, May/June INDUSTRIAL ENGINEERING & MANAGEMENT Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Write the differences between production management and industrial engineering. b) Briefly discuss the importance of industrial engineering. 2 a) What are the types of layouts? Explain with examples. b) If you were developing a computer program to evaluate alternative layouts, what variables would you include in it? Why? 3 a) Define operations management. Explain the nature and scope of operations management. b) Define the term work study and state its objectives. 4 a) Define the concept of inspection and explain various types of inspections. b) Define control charts. What are the objectives and importance of control charts? 5 a) Define Human resource management. What are its elements and what is its significance to organizational development? b) Explain different methods of merit rating. 6 a) Define quality circles. Explain its features and objectives b) Define Six-sigma. State its features and objectives. 7 a) What is the value engineering? Discuss its elements. b) Define supply chain management. Discuss the evaluation of a supply chain. 8 a) Explain the significance of using PERT/ CPM b) Discuss briefly various tools and techniques of project management

18 Set No. 2 Code No: R32036 R10 III B.Tech II Semester Regular Examinations, May/June INDUSTRIAL ENGINEERING & MANAGEMENT Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Define Industrial engineering? Discuss the development and applications of industrial engineering. b) Discuss Quantitative tools of industrial engineering and productivity Measurement? 2 a) Discuss the advantages and the disadvantages of process layout and product layout? b) Discuss preventive and breakdown maintenance? 3 a) Define production. Discuss the different types of production. b) What are the objectives of time study and how is it organized? 4 a) Define statistical quality control? Explain the significance and advantages of statistical Quality control? b) How do you draw inferences from a control chart? How can you improve the process by using control charts? 5 a) What are the key functions of a human resource manager? b) Define job evaluation and narrate the various steps involved for evaluating the jobs. 6 a) Write about ISO and explain the benefits of ISO registration. b) Discuss in detail the various applications of quality circle in the maintenance of quality production. 7 a) Explain in detail implementation procedure of value analysis? b) Compare and contrast Enterprise Resource Planning and Supply Chain 8 a) Define critical path. State the steps involved in determining critical path. b) Differentiate between PERT and CPM

19 Set No. 3 Code No: R32036 R10 III B.Tech II Semester Regular Examinations, May/June INDUSTRIAL ENGINEERING & MANAGEMENT Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Explain the concept of management and bring out its importance in present day Context. b) Discuss the principles of scientific management. 2 a) Discuss the factors influencing plant location. b) Discuss plant maintenance. 3 a) What is PMTS? What are the different types of PMTS and explain them? b) Explain the procedure, advantages and disadvantages of work sampling. 4 a) Define acceptance sampling. What are the various methods of acceptance sampling? b) Discuss in detail the applications of control charts. 5 a) What are the objectives and activities associated with man power planning? b) Define wage incentive plans. What are its objectives and drawbacks? 6 a) Briefly explain the structure of quality circles. b) Write the advantages and disadvantages of Six-Sigma. 7 a) Discuss the functions and significance of Enterprise Resource Planning. b) What are the various functions of supply chain management? 8 a) List out the rules for drawing the network diagrams. b) Enumerate the objectives, characteristics and assumptions of PERT and CPM

20 Set No. 4 Code No: R32036 R10 III B.Tech II Semester Regular Examinations, May/June INDUSTRIAL ENGINEERING & MANAGEMENT Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) What do you mean by management skills? How do skill requirements differ at various levels of management? b) Discuss Fayol s principles of management? 2 a) Discuss the quantitative techniques for optimal design of layouts? b) Discuss the objectives of plant layout? 3 a) Define Ergonomics? Discuss the principles of ergonomics of posture and movement? b) Define string diagram? How it is constructed? List out the advantages and disadvantages of string diagrams? 4 a) Define quality. Explain the importance of quality in the changing techno-economic scenario. b) Explain the parameters affecting acceptance sampling plans. 5 a) Differentiate personnel and industrial relations from Human Resource Management. b) Explain the following concepts with appropriate examples i) Job description ii) Job specification 6 a) Write in detail about the step by step implementation of a quality circle. b) Explain zero defect? How do you develop Hassle-free organisation with zero defect programme? 7 a) Define enterprise resource planning? State the advantages and disadvantages of enterprise resource planning? b) Explain various objectives of supply chain management. 8 a) Explain the assumptions underlying PERT and CPM network models applied in project management. b) Briefly explain project crashing with an example

21 INSTRUMENTATION & CONTROL SYSTEMS Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Distinguish between the following i) Accuracy and Precision ii) Resolution and Threshold iii) Reproducibility and Repeatability iv) Dead zone and Hysteresis. b) What are the different sources of errors in measurements and measuring instruments? Explain them. 2 a) Describe the properties of materials used for piezo electric transducers. Derive the expressions for voltage and charge sensitivities. b) Compare and contrast the advantages and limitations of resistance thermometers and thermistors. 3 a) Describe the construction and working of a Bourdon tube. Describe the C type, spiral and helical type bourdon gauges with neat diagram. b) Explain the construction, working and theory of Ionization pressure gauges for measurement of pressure. 4 a) With neat sketch explain the working principle of a bubbler gauge. b) Describe construction and working of an Electromagnetic flow meter. Explain its advantages and disadvantages. 5 a) What are the mechanical tachometers? Explain with examples. Describe the disadvantages of these. b) Explain the different methods adopted for the calibration of accelerometers. 6 a) List the procedure to mount a strain gauge with paper backing on the surface under study. b) Explain the method of usage of resistance strain gauge for bending compressive and tensile strains. 7 a) Explain how a sling psychrormeter is used to determine the dry and the wet bulb temperatures. b) With neat sketch explain the working principle of Strain gauge load cell. 8 Set No. 1 Code No: R32034 R10 Distinguish between a) Manual control system and Automatic control systems. b) Position control and Velocity control.

22 Set No. 2 Code No: R32034 R10 INSTRUMENTATION & CONTROL SYSTEMS Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) With a block diagram explain a generalized measurement system indicating various functional elements. b) State and explain the response of a first order system when subject to step input signal. 2 a) Describe the properties of materials used for piezo electric transducers. Derive the expressions for voltage and charge sensitivities. b) Compare and contrast the advantages and limitations of resistance thermometers and thermistors. 3 a) Explain briefly the working principle and its operation of Bourdon and diaphragm gauge. b) Describe the construction, working and theory of McLeod gauge for measurement of vacuum. 4 a) Explain how Doppler effect is used for measurement of flow velocities in ultrasonic flow meters. b) Explain the working principle of Laser Doppler anemometer? 5 a) Explain the construction and working of a fly ball tachometer. b) Explain the construction, principle of working and advantages of LVDT accelerometers. 6 a) Derive an expression for gauge factor resistance strain gauge. b) Explain the function of a dummy gauge in a strain gauge load cell. 7 a) With neat sketch explain the working of Hydraulic load cell with neat sketch. b) Explain the construction and working of a eddy current brake. What are its advantages and limitations? 8 Write short notes the following : a) Servomechanism [5] b) Temperature control system [5] c) Position control system. [5]

23 R10 Code No: R32034 Set No. 3 INSTRUMENTATION & CONTROL SYSTEMS Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Define the terms: (i) Repeatability (ii) accuracy (iii) Precision (iv) Linearity b) What are the different standard inputs for studying the dynamic response of a system? Define and sketch them. 2 a) Explain the construction and principle of a working of a LVDT. Explain the how the magnitude and direction of the displacement of core of an LVDT. b) Describe the working principle of total radiation pyrometers? List out its advantages and limitations. 3 a) Describe the construction and working of diaphragms. Explain how capsules are made from diaphragms.list the materials used for making diaphragms and the give the ranges of pressure over which they can be used. b) Explain the construction, working and theory of thermal conductivity gauges for measurement of vacuum. Explain how radiation effects are minimized. 4 a) With neat sketch explain in detail the functioning of any two flow measuring instruments working on Faraday s law of induced voltage b) Explain the principle of hotwire anemometer. What are its merits and limitations? 5 a) Discuss the principle of working of a seismic instrument explaining how it can be used to measure displacement velocity and acceleration. b) Name different electrical non-contact tachometers. Explain with neat diagram, working of an inductive pick up tachometer. 6 a) Explain one method of temperature compensation using an adjacent arm compensating gauge. b) Describe the working principles of strain gauge bridge with sketch. Indicate the arrangements for measurement of torque on a circular shaft. 7 a) With neat sketch explain the working of Hydraulic load cell with neat sketch. b) Sketch and explain the constructional details and working of a dew point meter. 8 a) Describe the operation of driver driving an automobile on the road and identify the components, input and output of the human system. b) What is Automatic control? Describe the automatic tank level control system.

24 Set No. 4 Code No: R32034 R10 INSTRUMENTATION & CONTROL SYSTEMS Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) How do you classify the measuring instruments? Exaplin the various types of instruments briefly. b) Why is calibration of instruments necessary? Explain the difference between direct and indirect calibration. 2 a) Explain how by using a differential arrangement, a capacitive transducer which works on the principle of variation of capacitance with displacement between the two plates, the response can be made linear b) Explain the principle of working of thermocouples. State the law of intermediate temperatures and intermediate metals for thermocouples 3 Describe with neat diagram the construction, working and theory of the following types of conductivity gauges Thermocouple and (ii) Pirani gauges. Give their advantages and disadvantages. 4 a) Enumerate the principle of operation of the following: i) Capacitive level indicator ii) Ultrasonic level measuring instrument b) Explain the constant temperature and constant current modes of operation of Hot wire anemometers for measurement of flow velocities.explain the advantages of constant temperature mode of operation. 5 a) Describe the working principle of D.C.Tachometer generator and what are its advantages and disadvantages. b) Describe with sketches the basic principle of working of stroboscope. List of its advantages and limitations. 6 a) Explain the principles operation of electrical resistance strain gauges and their merits and demerits. b) What is the function of Rosettes? Explain the working of (i) Rectangular strain gauge rosettes and (ii) Delta strain gauge rosettes. 7 a) What are Transmission dynamometers? Explain the constructional detail of any one type of transmission dynamometer. b) With neat sketch explain the working principle of Pneumatic load cell. 8 a) Distinguish between Manual control system and Automatic control systems. b) Describe typical closed-loop control systems that can be used in order to control the temperature of water being heated by steam, and Draw the block diagram of the arrangement and mention the use of feed back in application. 15

25 Set No. 1 Code No: R32031 R10 METROLOGY Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Determine the dimensions of hole and shaft for a fit 30H7 h8. 30mm lies between 18 and 30mm. IT7 = 16i, IT8 =25i. What is the type of fit and draw it? b) Explain the differences between hole and shaft basis systems. 2 a) What types of measuring systems are used for linear distance measurement? Explain any three of them with neat diagrams? b) Shafts of 75± 0.02 mm diameter are to be checked by the help of a Go, Not Go snap gauges. Design the gauge, sketch it and show its Go size and Not Go size dimensions. Assume normal wear allowance and gauge maker s tolerance. 3 a) Discuss the steps involved in computing flatness of surface plate with help of a diagram? b) Explain the working principle of Tools maker s microscope with neat diagram and briefly explain its application. 4 a) Explain the working principle of Tomlinson surface meter with a neat sketch. b) With neat sketches, explain the significance of some important parameters used for measuring surface roughness. Why so many parameters are needed? Explain. 5 a) With neat sketch explain the construction and working principle of differential pneumatic comparator. b) Write the advantages and disadvantages of the mechanical comparator? 6 a) With the aid of a neat sketch describe the principle of operation of a rolling gear testing machine. b) What are the various methods used for measuring tooth thickness of a Spur gear. Explain the principle involved with neat sketches. Under what circumstance each method is used. 7 a) Derive the formula for measuring the effective diameter of thread by 3-wire method. b) How to measure the pitch of the screw thread by using the tool maker s microscope? Discuss in detail. 8 a) Explain alignment test on lathe machine. b) Explain alignment test on milling machine. 1 of 1

26 Set No. 2 Code No: R32031 R10 METROLOGY Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Determine the actual dimensions to be provided for a shaft and hole of 20H 7 /f 8 fit. Size 20 mm falls in diameter steps of 18and 30 value of tolerance unit i (microns)=0.45d 1/ Value of tolerances for IT7=16i and IT8=25i. Mention the type of fit and show the diagram. b) Explain interchangeability with suitable example? 2 a) Describe with the help of a neat sketch, a vernier bevel protractor. b) State and explain the Taylor s principle of gauge design.explain the following in connection with gauge design: (1) Gauge maker s tolerance (2) Wear allowance. 3 a) Explain the working principle of autocollimator with neat diagram and briefly explain its application b) Explain the working principle of Michaleson s interferometer with neat diagram and mention the advantages. 4 a) Explain the working principle of Talysurf with a neat sketch b) What are the different methods used for measurement of surface finish? Explain? 5 a) With neat sketch explain the construction and working principle of Sigma comparator b) Write the advantages and disadvantages of the electrical comparator? 6 a) Explain the principle of measuring gear tooth thickness by base tangent method. What is the span length over 5 teeth of gear having 45 teeth module 4mm and pressure angle 20 o. b) How is the involute profile of gear tooth measured? Explain. 7 a) What is the best wire size? Derive an expression for the same in terms of the pitch and angle of the thread b) Briefly describe major, minor and effective diameter of thread with neat diagram? 8 a) Explain alignment test on milling machine. b) Explain alignment test on drilling machine. 1 of 1

27 R10 Code No: R32031 Set No. 3 METROLOGY Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) Determine the actual dimensions to be provided for a shaft and hole of 90 mm size for H8e9. Size 90 mm falls in diameter steps of 80 and 100 value of tolerance unit : i= 0.45 ( 3 D ) D Value of tolerances for IT8 and IT9 grades are 25i and 40i. Value of fundamental Deviation for 'e' type shaft is 11D Mention type of fit and show the diagram? b) Explain selective assembly with suitable example? 2 a) Describe a Sine bar with the help of a near sketch? Mention the applications of sine bar? b) How the external diameter of rod can be measured with the help of micrometer? Explain with neat diagram? 3 a) Explain the working principle of NPL flatness interferometer with neat diagram and mention the advantages. b) Explain the working principle of straight edges with neat diagram and mention the applications. 4 a) Explain ISI symbols used for indication of surface finish? b) Explain the working principle of Talysurf with a neat sketch. 5 a) With neat sketch explain the construction and working principle of electronic comparator b) What is a comparator? State different types of comparators? Compare mechanical comparator with electrical comparator. 6 a) Describe a gear tooth vernier caliper and explain its use for checking tooth thickness and depth of tooth. b) Describe the method of inspecting the profile of spur gear by using involute measuring machine. 7 a) Describe the two wire method of finding the effective diameter of screw threads. b) Explain the errors in screw threads with neat diagrams? 8 a) Explain alignment test on drilling machine. b) Explain alignment test on lathe machine. 1 of 1

28 Set No. 4 Code No: R32031 R10 METROLOGY Time: 3 hours Max. Marks: 75 All Questions carry equal marks 1 a) A hole and shaft combination of 25 mm nominal size. H7 hole limit are mm, and mm e8 shaft limit are and mm state the values of : (i) Maximum and minimum clearance obtainable. (ii) Allowance. (iii) Tolerance on the hole and the shaft. (iv) type of fit and draw the fit b) What are the main differences between unilateral and bilateral tolerance system? Explain? 2 a) Describe the method of checking the angle of a taper plug gauge using rollers, micrometer and slip gauges, b) How the slip gauges are calibrated? Explain? 3 a) Explain the working principle of optical projector with neat diagram and mention the advantages. b) Explain the working principle of NPL gauge interferometer with neat diagram and mention the applications. 4 a) What is Profilograp? Explain with neat diagram? b) What are the different numerical methods used for assessment of surface finish? Explain any two methods? 5 a) With neat sketch explain the construction and working principle of solex pneumatic comparator. b) Compare mechanical comparator with pneumatic comparator. 6 a) How to check the composite errors of the gear by using Parkinson gear testing machine? Explain. b) How pitch measurement of spur gear is carried out? Explain? 7 a) Describe the two wire method of finding the effective diameter of screw threads b) What are the different types of thread gauges used for measurement of screw thread profile? Explain? 8 a) Differentiate between Alignment test and Performance test of a machine tool. b) Explain alignment test on drilling machine. 1 of 1