WHIRLING SPEED OF SHAFT

EXP.NO:

DATE:AIM :

To determine the whirling speed for various diameter shafts experimentally and compare it with the theoretical values.

APPARATUS REQUIRED:

1. Different diameter shafts, 2.measuring scale, 3. Alien key, 4. AC voltage regulator, 5. Digital speed sensor, 6. vernier caliper

OBSERVATION:For shaft 1 vibrating length (l): .....................m

youngs modulus(E): .....................N/m2 Diameter of the shaft (D):.....................m Density of the shaft material:...................kg/m3

For shaft 2 vibrating length (l): .....................m

youngs modulus(E): .....................N/m2 Diameter of the shaft (D):.....................m

Density of the shaft material:...................kg/m3

Formula used:

1. Defection ( (s) = 5Wl4/384EI2. Moment of inertia, I= (/64) D43. Weight of the shaft (W)=Agl4. Whirling speed

(s)th=[0.4985/((s/1.27)](s)exp=2 N/60DESCRIPTION:

The speed at which the shaft runs so that additional deflection of the shaft from the axis of rotation becomes infinite is known as critical speed.

Normally the centre of gravity of a loaded shaft will always displace from the axis of rotation although the amount of displacement may be very small. As a result of this displacement, the centre of gravity is subjected to a centripetal acceleration as soon as the Shaft begins to rotate. The inertia force acts radially outwards and bends the shaft. The bending of shaft not only depends upon the value of eccentricity, but also depends upon the speed at which the shaft rotates.PROCEDURE:1. The shaft is to be mounted with the end condition as simply supported.2. The speed of rotation of the shaft is increase gradually.

3. When the shaft vibrates violent in fundamental mode, the speed noted down.

4. The above procedure is repeated for remaining shafts.TABULATION:

S.NOShaft diameter

Moment of inertiadeflectionWhirling speed

theoreticalexperimental

1

2

RESULT: