DOM QUESTION PAPER - 1

QUESTION PAPER – 1

DYNAMICS OF MACHINES

QUE NO 1:-

DETERMINE THE REQUIRED INPUT TORQUE ON THE CRANK OF A SLIDER CRANK MECHANISM FOR THE STATIC EQUILIBRIUM WHEN THE APPLIED  PISTON LOAD IS 1500 N. THE LENGTHS OF THE CRANK AND THE CONNECTING ROD ARE 40MM AND 100 MM RESPECTIVELY AND THE CRANK HAS TURNED THROUGH 45⁰ FROM THE INNER DEAD CENTER.

QUE NO 2:-

THE CRANK AND THE CONNECTING ROD OF A VERTICAL SINGLE CYLINDER GAS ENGINE RUNNING AT 1800 RPM ARE 60 MM AND 240 MM RESPECTIVELY. THE DIAMETER OF THE PISTON IS 80 MM AND THE MASS OF THE RECIPROCATING PART IS 1.2 KG. AT A POINT DURING THE POWER STROKE WHEN THE PISTON HAS MOVED 20 MM FROM THE TOP DEAD CENTRE POSITION , THE PRESSURE ON THE PISTON 800 KN/M² DETERMINE THE:

(i)                 NET FORCE ON THE PISTON

(ii)               THRUST IN THE CONNECTING ROD

(iii)             THRUST ON THE SIDES OF CYLINDER WALLS

(iv)             ENGINE SPEED AT WHICH THE ABOVE VALUES ARE ZERO

QUE NO 3:-

(A) DEFINE (I) PITCH CYLINDER, (II) PITCH POINT (III) RACK.

(B) TWO 20⁰ GEARS HAVE A MODULE PITCH OF 4 MM. THE NUMBER OF TEETH ON GEARS 1 AND 2 ARE 40 AND 24 RESPECTIVELY. THE GEAR 2 ROTATES AT 600 RPM; DETERMINE THE VELOCITY OF SLIDING WHEN THE CONTACT IS AT THE TIP OF THE TOOTH OF GEAR 2. TAKE ADDENDUM EQUAL TO ONE MODULE. ALSO FIND THE MAXIMUM VELOCITY OF SLIDING.

QUE NO 4:-

AN EPICYLIC GEAR CONSISTS OF A PINION, A WHEEL OF 40 TEETH AND AN ANNULUS WITH 84 INTERNAL TEETH CONCENTRIC WITH THE WHEEL. THE PINION GEARS WITH THE WHEEL AND THE ANNULUS. THE ARM THAT CARRIES THE EXIT OF THE PINION ROTATES AT 100 RPM.IF THE ANNULUS IS FIXED, FIND THE SPEED OF THE WHEEL. IF WHEEL IS FIXED, FIND THE SPEED OF THE ANNULUS.

QUE NO 5:-

DESCRIBE IN BRIEF THE WORKING OF VARIOUS TYPES OF GOVERNORS WITH THE HELP OF NEAT DIAGRAMS.

QUE NO 6:-

THE FOLLOWING DATA RELATE TO A FOUR LINK MECHANISM:

A=55 MM, B=165 MM, C=80 MM, D=150 MM

M_A=0.045 KG, M_B=0.13 KG, M=0.05 KG

G_A=28 MM, G_B=25 MM, G_C=42 MM

Φ_A=0⁰, Φ=13⁰, ΦC=0⁰

COMPLETE FORCE BALANCING BY ADDING COUNTER MASSES TO THE INPUT AND OUTPUT LINKS IS DESIRED. DETERMINE THE MASS-DISTANCE VALUES AND ANGULAR POSITION OF EACH COUNTER MASS.

QUE NO 7:-

(A) DESCRIBE IN BRIEF OPEN AND CLOSED LOOP CONTROL.

(B) DESCRIBE BLOCK DIAGRAM WITH THE HELP OF EXAMPLES AND NEAT DIAGRAM.

(C) DISCUSS SECOND ORDER SYSTEM RESPONSE.

QUE NO 8:-

 EACH WHEEL OF A MOTOR A MOTOR-CYCLE IS OF 600 MM DIAMETER AND HAS A MOMENT OF INERTIA OF 1.2 KG-M². THE TOTAL MASS OF THE MOTOR CYCLE AND THE RIDER IS 180 KG AND THE COMBINED CENTER OF MASS IS 580 MM ABOVE THE GROUND LEVEL WHEN THE MOTOR-CYCLE IS UPRIGHT. THE MOMENT OF INERTIA OF THE ROTATING PARTS OF THE ENGINE IS 0.2 KG-M². THE ENGINE SPEED IS 5 TIMES THE SPEED OF THE WHEELS AND IS IN THE SAME SENSE. DETERMINE THE ANGLE OF HEEL NECESSARY WHEN THE MOTOR-CYCLE TAKES A TURN OF 35 M RADIUS AT SPEED OF 54 KM/H.