BE - SEMESTER VI MID SEMESTER EXAMINATION SUMMER 2015 SUBJECT: DYNAMICS OF MACHINERY (161901) DATE: 09-03-2015 TIME: 02:00 pm to 03:13 pm TOTAL MARKS: 30 Q.1 (a) Define the following terms in short: (i) Natural frequency, (ii) Damping Factor, (iii) Whirling of Shaft (iv) Force Transmissibility (v) Logarithmic Decrement. (b) For an uncoupled two cylinder locomotive engine, derive (a) Variation in tractive force, (b) Hammer blow, (c) Swaying couple. Q.2 (a) A mass of 20 kg is mounted on two slabs of isolators placed one over the other. One of the isolator is of rubber having stiffness 5000 N/m and damping coefficient of 200 N-sec/m while the other isolator is of felt with stiffness of 15000 N/m and damping coefficient of 400 N-sec/m. If the system is set in motion in vertical direction, determine: Damped natural frequency, Damping factor, and Undamped natural frequency of the system. (b) A single cylinder vertical petrol engine of total mass 320 kg is mounted upon a steel chassis frame and causes a vertical static deflection of 0.2 cm. The reciprocating parts of the engine have a mass of 24 kg and move through a vertical stroke of 15 cm with S. H. M. A dashpot is provided, the damping resistance of which is directly proportional to the velocity and amounts to 490 N at 0.3 m/sec. Determine (a) The speed of the driving shaft at which resonance will occur. (b) The amplitude of steady state force vibration when the driving shaft of engine rotates at 480 rpm. (c) Determine the natural frequency of vibration of a system depicted in figure 2.1, where each spring is having stiffness k. Q.2 (a) A disc of torsion pendulum has a moment of inertia of 0.05 kg-m 2 is immersed in a viscous fluid. During vibration of pendulum, the observed amplitudes on the same side of the neutral axis for successive cycles are found to decay 50% of the initial value. Determine (i) Logarithmic decrement. (ii) Damping torque per unit velocity (iii) The periodic time of vibration. Assume G = 4.5 10 10 N/m 2 for the material of shaft. For shaft d = 0.10 m and l = 0.50 m (b) A single cylinder engine has a mass of 100 kg and is acted upon by a vertical unbalanced force of 400sin(13πt ) N. The engine block is supported on a spring having a stiffness 60 kn/m and a damper which gives a damping force [3] [4] [3] [4] [3]
of 700 N per unit velocity. Find the damping ratio and Magnification factor. (c) A pendulum consists of a stiff weightless rod of length l carrying a mass m on its end as shown in figure 2.2. Two springs each of stiffness K are attached to the rod at a distance a from the upper end. Determine the frequency for small oscillation. [3] Q.3 (a) A two cylinder locomotive engine has the following specifications: Reciprocating masses/cylinder = 300 kg, Crank radius = 90 mm, Angle between crank = 90, Driving wheel diameter = 1780 mm, Distance between cylinder centers = 640 mm, Distance between driving wheel plans = 1500 mm. Determine: (i) The fraction of reciprocating masses to be balanced if the hammer blow is not to exceed 45 kn at 95 Km/hr speed. (ii) The variation in the tractive effort. (iii) The magnitude of swaying couple. (b) Derive an expression for force transmissibility. Q.3 (a) A, B, C and D are four masses attached on a shaft at radii 0.1 m, 0.225 m, 0.15 m and 0.15 m respectively. Planes in which masses revolve are spaced 0.6 m apart and the weights of B, C and D are 10 kg, 5.5 kg and 3.6 kg respectively. Find the required mass at A and the relative angular positions of all the four masses so that the shaft is in complete balance. Use any method. (b) The support of a spring mass system is vibrating with an amplitude of 5 mm and a frequency of 1150 cycle/min. If the mass is 0.9 kg and the spring has a stiffness of 1960 N/m, determine the amplitude of vibration of mass. What amplitude will result if a damping factor of 0.2 is induced in the system. Figure 2.1 Figure 2.2
BE - SEMESTER VI MID SEMESTER EXAMINATION SUMMER 2015 SUBJECT: I.C. ENGINES (161902) DATE: 10-03-2015 TIME: 2:00 PM to 3:15 PM TOTAL MARKS:30 Q.1 (a) Draw & explain valve Timing diagram of 4 stroke petrol and diesel engine? (b) Explain MPFI system? Q.2 (a) Explain method or arrangement of supercharging? (b) Explain properties of Alcohols? Q.2 (a) Calculate the Percentage change in efficiency of air standard Otto cycle having compression ratio of 5 for the following cases (1) The specific heat at constant volume increases by 3% (2) The specific heat at constant pressure increases by 4 %.(one derivation must be required either C p or C v ) (b) Difference between S.I. & C.I. engine? Q.3 (a) With the help of Pressure-Crank angle diagram explain the stages of combustion in S.I Engine. (b) Assumption made for fuel air cycle? Q.3 (a) Derive and Explain analysis of simple carburetor. (b) Explain Detonation with neat sketch? Also gives the effect of engine variables on detonation? ****************************************************************************************************
BE - SEMESTER VI MID SEMESTER EXAMINATION SUMMER 2015 SUBJECT: COMPUTER AIDED DESIGN (161903) DATE: 11-03-2015 TIME: 02:00 pm to 03:15 pm TOTAL MARKS: 30 Q.1 (a) Enlist and explain components of CAD Hardware. Also, draw the Block-Diagram for a Stand-alone CAD System (b) Explain the concept of Finite Element Analysis. Discuss various steps involved in FEA Q.2 (a) Explain with neat sketch different standard elements used in FEA (b) Indicate which raster location would be chosen by Bresenham s Algorithm when scan converting a line from Point (1,1) to Point (10,5). Q.2 (a) Explain the co-ordinate reference systems used in FEA. List out the advantages and disadvantages of FEA (b) Explain Cubic Curve in detail Q.3 (a) Explain Bezier Curves. Also, enlist the properties of Bezier Curves. (b) Triangle ABC with A(0,0), B(4,2) and C(2,4) is translated in X- Direction by 3 units and in Y-Direction by 2 units. It is then rotated by 90 Degree Counter-Clockwise (Anti-Clockwise) about the new position of B. Find the new Co-ordinates of points A,B and C Q.3 (a) Explain the flow-chart for DDA Algorithm (b) Find the new co-ordinates of a triangle PQR, P(4,4), Q(10,8) and R(4,8),when reflected about an arbitrary line y=x+2. ****************************************************************************************************
BE - SEMESTER VI MID SEMESTER EXAMINATION SUMMER 2015 SUBJECT: Alternate Energy Sources (161904) DATE: 12-03-2015 TIME: 2:00 pm to 3:15 pm TOTAL MARKS: 30 Q.1 (a) Define the following terms: (1) Angle of Latitude (Ф) (2) Angle of Altitude (α) (3) Zenith Angle (θ z ) (4) Hour Angle (ω) (5) Declination Angle (δ) (b) Explain need for Alternate energy sources. Mention advantages and disadvantages of Alternate energy sources. Q.2 (a) Compare vapour dominated and liquid dominated geothermal resources. (b) What do you mean by solar distillation? Explain solar still with a neat sketch. Q.2 (a) Write down advantages and disadvantages of geothermal energy over other energy forms. (b) Mention the types of bio gas plants. Explain any one of them. Q.3 (a) Explain the working of pyranometer with neat sketch. (b) Discuss the factors affecting the biogas products in detail. Q.3 (a) Calculate the number of day light hours in Delhi on 22 December 2014. Take latitude (Ф) = 28 0 35 (b) Write down advantages and disadvantages of biogas plant. ****************************************************************************************************
BE - SEMESTER VI MIDSEMESTER EXAMINATION SUMMER 2015 SUBJECT: CONTROL ENGINEERING (161905) DATE: 13-03-2015 TIME: 02:00 pm to 03:15 pm TOTAL MARKS: 30 Instructions: 1.All the questions are compulsory. Q.1 (a) Explain the difference between Open loop and Close loop control system with examples. Compare their merits and demerits. (b) Compare between hydraulic and pneumatic control system. Q.2 (a) Using the block diagram reduction techniques, find the closed loop transfer function of the system whose block diagram is given in Fig.1 Fig-1 (b) Name the various components used in any hydraulic circuits. Explain vane pump with neat sketch briefly. Q.2 (a) Find the transfer function for the fig.2 using signal flow graphs. Fig.2 (b) Explain the construction, working and application of a hydraulic intensifier. [P.T.O.]
Q.3 (a) Define state, state vector, and state space in the context of state-space approach and obtain state model for the following transfer function C(s) R(s) = (s + 2) s + 1 (S + 3) [07] (b) Define the following Terms (i) Linguistic variables (ii) Fuzzy Logic (iii) [03] Fuzzy Set Q.3 (a) What is Fuzzy logic? Explain the concept of Fuzzy logic with a suitable example. (b) Explain Adaptive Control System ****************************************************************************************************
BE - SEMESTER VI MID SEMESTER EXAMINATION SUMMER 2015 SUBJECT: Heat & Mass transfer (161906) DATE: 14-03-2015 TIME: 02:00 pm To 03:15 pm TOTAL MARKS: 30 Q.1 (a) Derive the most general heat conduction equation in Cartesian coordinate system. (b) Find the heat flow rate through a composite wall as shown below. Assume one dimensional flow. Consider KA=150W/m C, KB=30W/m C, KC=65W/m C, KD=50W/m C Q.2 (a) Define the following terms: 1. Total emissive power 2.Solid angle. 3. Thermal diffusivity 4. Shape factor. 5. Types of bodies in radiation. (b) What do you mean by critical thickness of insulation and derive the condition for maximum heat flow rate through a pipe. Q.2 (a) d Energy equation of heat dissipation from a fin is θ d x 2 m2 θ = 0. Each notation have got usual meaning. Using this equation derive an expression of heat dissipation from an infinitely long fin. (b) Explain Kirchoff s law of radiation along with it s prove. Q.3 (a) Determine the rate of heat loss by radiation from a steel tube of outside diameter 7 cm and length 3m at a temperature of 227 C. If the tube is located within a square brick conduit of 0.3 m side and at 27 C. Take emissivity of steel and brick as 0.79 and 0.93 respectively.
(b) What is a Radiation shield? When it is used? Also derive the relation between the net heat transfer between two long parallel plates with and without providing the radiation shield in between the surfaces. Q.3 (a) Derive the expression for radiant heat exchange between two non-black parallel surfaces. (b) A thin hollow cylinder of 8 cm diameter and 10cm length is shown in fig.1. below. If the radiant shape factor of the circular surface of this cylinder is.172. Find the shape factor of the curved surface of the cylinder with respect to itself (F33). Surface 3 Surface 1 Surface 2 L Fig. 1.
BE - SEMESTER VI MID SEMESTER EXAMINATION SUMMER 2015 SUBJECT: INDUSTRIAL ENGINEERING (161907) DATE: 16-03-2015 TIME:11:00 am to 12:15 pm TOTAL MARKS:30 Q.1 (a) What are the objective of the plant location and also write in brief the choice of site for location. (b) Define plant lay-out and explain types of lay-outs. Q.2 (a) What is PPC? Explain function of PPC in brief. (b) Name various types of production systems and also explain the characteristics of different types of production systems. Q.2 (a) Explain Assembly line of balance. (b) Industrial Dispute act. Explain in detail. Q.3 (a) Explain Factories Act. (b) What is job evaluation? Explain various job evaluation methods. Q.3 (a) Characteristics of Entrepreneur? (b) Discuss: Total Quality Management. ****************************************************************************************************