Experiment # 01
Objective:
1-To find the efforts required to raise a range of loads at a particular velocity ratio
2-To find the efficiency at each load
3-To find the effect of friction at each load
Background:
Consider two pulleys coupled by a belt, as shown below. Let the radii of one pulley is ‘a’ and the radii of other pulley is ‘b’. A flexible non-slip belt is used for the transmission of power from one pulley to other. The distance moved by the belt on circumference of each pulley is same.
Apparatus:
1- Pulleys 2- Belt
3- Vernier Calipers 4- Loads
What is a pulley?
Basically a pulley is a mechanical device which is used to; lift a load by applying some effort. The basic aim is to keep the magnitude of applied effort as small as possible through clever design of pulley. Belts are used to transmit the power in all pulley mechanisms.
Procedure:
First of all, fix a white paper on wall in alignment with the pulley mechanism. Apply a particular amount of load on loading hangers. Now apply weights, to ‘effort hangers’ until the loading hangers displaced slightly upward from their location. Note this distance and the corresponding effort to lift this load. Repeat this procedure for different values of load. Here again note the upward deflection and corresponding applied effort.
Observations and Calculations:
Distance moved when 0.7 N load is applied = 4mm
Distance moved when 1.0 N load is applied = 5mm
Distance moved when 1.5 N load is applied = 8mm
Efficiency = (work output/work input) × 100
| Sr. No. | Load
| Effort | Work Input | Work Output | Effort of Friction
| Efficiency |
| 1 | ||||||
| 2 | ||||||
| 3 |
Error Analysis:
The slipping of belt on pulleys must be avoided. Also the movement of pulleys must be smooth to avoid the jerks and hence the uncertainty in measurement. Carefully note the displaced distance for accurate measurement. Weights must be applied gently on the hangers.
Comments:
It is a good experiment which tells us that how the clever arrangement of pulleys can be used for lifting maximum loads with minimum inputs.
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Experiment # 02
Objective:
To investigate the belt drive and find the efficiency at each load
Background:
Consider two pulleys coupled by a belt, as shown below. Let the radii of one pulley is ‘a’ and the radii of other pulley is ‘b’. A flexible non-slip belt is used for the transmission of power from one pulley to other. The distance moved by the belt on circumference of each pulley is same.
Apparatus:
1- Pulleys 2- Belt
3- Vernier Calipers 4- Loads
What is a pulley?
Basically a pulley is a mechanical device which is used to; lift a load by applying some effort. The basic aim is to keep the magnitude of applied effort as small as possible through clever design of pulley. Belts are used to transmit the power in all pulley mechanisms.
Procedure:
First of all, fix a white paper on wall in alignment with the pulley mechanism. Apply a particular amount of load on loading hangers. Now apply weights, to ‘effort hangers’ until the loading hangers displaced slightly upward from their location. Note this distance and the corresponding effort to lift this load. Repeat this procedure for different values of load. Here again note the upward deflection and corresponding applied effort.
Observations and Calculations:
· Distance Moved = 10mm, Load = 1N (Medium Pulley), Effort = 0.5 N (Rear Pulley)
· Distance Moved = 4mm, Load = 3N (Rear Pulley), Effort = 2.5N (Rear Pulley)
· Distance Moved = 10mm, Load = 4N (Front Pulley), Effort = 1N (Rear Pulley)
· Distance Moved = 10mm, Load = 3.5N, Effort = 2N
· Distance Moved = 5mm, Load = 2N, Effort = 1N
Efficiency = (work output/work input) × 100
| Sr. No. | Load
| Effort | Work Input | Work Output | Effort of Friction
| Efficiency | Pulley Arrangement |
Error Analysis:
The slipping of belt on pulleys must be avoided. Also the movement of pulleys must be smooth to avoid the jerks and hence the uncertainty in measurement. Carefully note the displaced distance for accurate measurement. Weights must be applied gently on the hangers.
Comments:
It is a good experiment which tells us that how the clever arrangement of pulleys can be used for lifting maximum loads with minimum inputs.
Experiment # 03
Objective:
To find out pressure with a Bourdon Tube (pressure gauge) and compare this pressure with theoretical results
Background:
Actually pressure is defined as the ratio of applied force and corresponding area. Here we determine the applied pressure by subjecting a fluid (oil) to a pressure and balancing it with the applied pressure until the fluid attains equilibrium. At this instant, the applied pressure equals to the pressure of the oil and hence determined through the apparatus.
Apparatus:
1- Dead weight calibrator
2- Oil
3- Weights
4- Vernier calipers
What is a Pressure?
Pressure is defined as force per unit area. In other words, it tells us that if a particular amount of force is applied on a particular area then the concentration of force there is characterized as pressure.
Procedure:
Apply weights at the top of the area as shown in figure. Keep valve closed at this instant. After applying the mass open the valve such the piston moves downward under the action of weight on it until a point reaches where the pressure generated due to the applied weights is exactly equal to the pressure of the fluid in the other cylinder. This pressure is noted by the dial gauge. This gauge is calibrated in ‘bars’. So convert it into metric units. Compare these practically calculated values of pressure with theoretically calculated values.
Observations and Calculations:
Zero error of dial gauge = 0.05 bar
Mass of piston = 0.5 kg
Piston Diameter = 18 mm
Now to calculate the theoretical pressure acting on the piston, we use the definition of pressure
P = F/A
Force ‘F’ is given by
F = mass of applied weight × g
Area ‘A’ is given by
A = π × (piston diameter)2 / 4
| Sr. No | Applied mass (Kg) | Applied Load (Applied mass × g) | Area (m2) | Theoretical Pressure (N/m2) | Practical Pressure (bar) | Practical Pressure (N/m2) | Difference |
Error Analysis:
Open the valve at appropriate time to avoid uncertainty. Estimate the error in dial gauge. Apply weights on piston gently. As the gauge is calibrated in ‘bar’, so keep in mind to convert the noted values into metric units.
Comments:
It is an accurate method of determining the pressure due to precise design of the apparatus.
Experiment # 04
Objective:
Determination of the operation and characteristics of three basic types of flow meter
Background:
Actually here we are going to analyze the flow rate of water by using three different types of flow meters which are as follows:
i- Venturi Meter
ii- Orifice Plate
iii- Rota Meter
Water enters the apparatus through the lower left-hand end and flows horizontally through a sudden enlargement into a transparent Venturi meter, and into an orifice plate, a 90º elbow changes the flow direction to vertical and connects to a variable area flow meter (Rota Meter). The static head at various points in the flow path may be measured on a manometer panel. The water flow through the apparatus is controlled by the delivery valve of the Hydraulics Bench and the flow rate may be confirmed by using the volumetric measuring tank of the Hydraulics Bench
Apparatus:
1- Hydraulics Test Bench
2- Stop Watch
Procedure:
Direct the flow of water from sump tank to volumetric tank by using discharge valve. Ensure the absence of bubbles from the flow of water. Now note the time taken by water to occupy a particular volume in volumetric tank by using stop watch. Also note the height of fluid, raised in the tubes of manometer by using the scale which is fixed behind them. Note the reading of orifice plate as well as Rota meter. Repeat this procedure for different volumes occupied by discharged water.
Observations and Calculations:
As we know that Bernoulli’s equation is given by
Continuity equation is given by
For Ideal Flow
For Actual Flow
Here
Cd = Coefficient of discharge = 0.98
D2 = Throat Diameter = 16mm ; D1 = Inlet Diameter = 26mm
At = Throat Area = 2.011 × 10-4m2 ; A1 = Inlet Area = 5.309 × 10-4m2
Ρ = density of water = 1000kgm-3
For Orifice plate coefficient of discharge = 0.63
| Sr. No | Manometer Reading
| Rota-meter Reading (L/min) | Volume Occupied (Liters) | Time taken (Sec) | ||||
After putting values flow rate for ideal flow comes out to be ‘18.13 L/min’ ………………………………………. While flow rate for actual flow from formula comes out to be ’17.77 L/min’………………………………………
Error Analysis:
Ensure the absence of air bubbles. Handle discharge valve appropriately.
Experiment # 05
Objective:
Determination of the coefficient of discharge of Venturi meter
Background:
Water enters the apparatus through the lower left-hand end and flows horizontally through a sudden enlargement into a transparent Venturi meter. The static head at various points in the flow path may be measured on a manometer panel. The water flow through the apparatus is controlled by the delivery valve of the Hydraulics Bench and the flow rate may be confirmed by using the volumetric measuring tank of the Hydraulics Bench
Apparatus:
3- Hydraulics Test Bench
4- Stop Watch
Procedure:
Direct the flow of water from sump tank to volumetric tank by using discharge valve. Ensure the absence of bubbles from the flow of water. Now note the time taken by water to occupy a particular volume in volumetric tank by using stop watch. Also note the height of fluid, raised in the tubes of manometer by using the scale which is fixed behind them. Repeat this procedure for different volumes occupied by discharged water.
Observations and Calculations:
As we know that Bernoulli’s equation is given by
Continuity equation is given by
For Ideal Flow
For Actual Flow
Here
Cd = Coefficient of discharge = 0.98
D2 = Throat Diameter = 16mm ; D1 = Inlet Diameter = 26mm
At = Throat Area = 2.011 × 10-4m2 ; A1 = Inlet Area = 5.309 × 10-4m2
Ρ = density of water = 1000kgm-3
For Orifice plate coefficient of discharge = 0.63
| Sr. No | H1 (cm) | H3 (cm) | Volume Occupied (Liters) | Time taken (Sec) |
After putting values ideal flow rate comes out to be ‘35.35 L/min’………………………
On the other hand actual flow rate is ’15.89 L/min’ ……………………….
So coefficient of discharge is ‘0.45’ …………………………….
Error Analysis:
Ensure the absence of air bubbles. Handle discharge valve appropriately.
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