Bernoulli's Theorem Lab

• Lab 1: Bernoulli's Theorem
• The objective is to experimentally verify Bernoulli's equation and plot the total energy line versus distance.
• The theory is based on the law of conservation of energy, stating that the total energy remains constant between two sections of a flow field, provided there is no energy loss or gain and the flow is steady.

Energy Equation

• The energy equation is expressed as:
  • E = (P/ρg) + (V²/2g) + Z
• E represents the total energy.
• P/ρg represents the pressure energy per unit weight of fluid or pressure head.
• V²/2g represents the kinetic energy per unit weight.
• Z represents the potential energy per unit weight.

Experimental Setup

• The experimental setup is a self-contained recirculating unit that includes:
  • A sump tank
  • A constant head tank
  • A centrifugal pump for water lifting
  • A measuring tank
  • Control valves and a bypass valve to regulate water flow
  • A Perspex conduit with varying cross-sections (converging and diverging sections)
  • Piezometer tubes fitted at regular intervals on the test section
• Conduit connects to a constant head tank at the inlet
• Valve regulates water flow through the test section at the outlet
• Discharge is measured using the measuring tank and a stopwatch once steady state is achieved.

Required Utilities

• Utilities required include:
  • A single-phase power supply of 220 Volts, 50 Hz, 5 Amp with earth connection
  • Water supply
  • Space of 1.6 m × 0.5 m
  • Drain

Starting Procedure

• Apparatus must be cleaned, removing dust from all tanks
• All provided drain valves must be closed.
• Fill sump tank with clean water, ensuring there are no foreign particles.
• Flow control valve at the end of the Test Section should be closed.
• The Flow Control Valve and By-Pass Valve on the water supply line to Overhead Tank should be opened.
• All panel switches must be in the OFF position
• Switch the Main Power Supply on, making sure it is 220 V AC, 50 Hz

Operational Procedures

• Turn on the pump.
• Regulate water flow through the test section using the Gate Valve at the end of the Test Section.
• Measure the flow rate with the measuring tank and stopwatch.
• Velocity is calculated as V = Q/a.
• Discharge is calculated as Q = v/t = (A x R)/t

Standard Data

• Acceleration due to gravity (G) = 9.81 m/s²
• Area of the Measuring Tank (A) = 0.1 m²

Formulas

• Total Energy (E) is calculated as E = (P/ρg) + (V²/2g) + Z

Closing Procedures

• Turn off the pump when the experiment is completed.
• Switch off the power supply to the panel.
• All tanks should be drained using the drain valves.

Precautions and Maintenance

• Do not run the pump at low voltage (less than 180 volts).
• Do not fully close the Delivery line and By-Pass line valves simultaneously.
• Ensure the apparatus is kept free from dust.
• To prevent clogging, run the pump at least once every two weeks.
• Grease or oil the rotating parts once every three months.
• Always use clean water.
• If the apparatus remains unused for over a month, drain it completely and fill the pump with cutting oil.

Troubleshooting

• Open the back cover and manually rotate the shaft if the pump gets jammed.
• Switch off the main power for 15 minutes if the pump overheats, avoiding simultaneous closure of the flow control valve and bypass valve during operation.

Lab 2: Venturimeter and Orificemeter

Aim

• To demonstrate the application of Venturimeter and Orificemeter as flow meters.
• To determine the Coefficient of Discharge, Cd.

Theory

• A constriction in a closed channel results in increased velocity and kinetic energy, and a corresponding reduction in pressure, as described by Bernoulli's Theorem
• Rate of discharge can be calculated using pressure reduction, area available for flow, fluid density, and the Coefficient of discharge (Cd), which accounts for stream contraction and frictional effects.

Venturimeter

• Consists of:
  • An inlet section
  • A convergent cone
  • A cylindrical throat
  • A gradually divergent cone
• Inlet solution has the same diameter as that of pipe, followed by a convergent cone
• Convergent cone tapers from the original pipe size to the throat
• The throat is a short, parallel-sided tube with a smaller cross-sectional area than the pipe
• The divergent cone gradually increases from the throat size back to the original pipe size
• Pressure taps are provided at the inlet section and the throat

Orificemeter

• Consists of a flat circular plate with a concentric circular hole (orifice) in the pipe's axis.

Description of Apparatus

• Contains a Venturimeter and an Orificemeter fitted in a pipeline
• Pipeline is connected to a common inlet
• Separate control valves downstream regulate the flow through each device independently
• Pressure tapings from the inlet and throat of the Venturimeter, and inlet and outlet of the Orificemeter, connect to a differential manometer
• Discharge is measured using a measuring tank and a stopwatch

Required Utilities

• Power supply: Single Phase, 220 Volts, 50 Hz, 5 Amp with Earth
• Water Supply
• Drain
• Space required: 1.6 m × 0.6 m

Experimental Procedure (Starting)

• Clean the apparatus to remove dust in all tanks
• Close the drain valves
• Fill the sump tank with clean water, ensuring there are no foreign particles
• Close all Flow Control Valves on the waterline and open the By-Pass Valve.
• Check and adjust the mercury level in the manometer tube to be approximately half-full.
• Close all Pressure Taps of Manometer connected to the Venturimeter & Orificemeter
• Ensure the On/Off Switch on the Panel is in the OFF position
• Switch on the Main Power Supply (220 Volts AC, 50 Hz)
• Switch on the Pump

Experimental Procedure (Operational)

• Regulate water flow using the Flow Control Valves for the desired test section
• Slowly open the Pressure Taps of the Manometer for the related Test section to avoid pressure shocks to the manometer fluid
• Slowly open the air release Valve on the Manometer to release any air within; close these valves once air is purged.
• Adjust water flow rate in the selected section using the Air Control valves
• Record the Manometer reading
• Measure water flow discharged through the test section using the Stop Watch and Measuring Tank
• Steps 10 to 16 are repeated for different water flow rates by operating the Control Valve and By-Pass valve
• For alternative desired test section: open the By-Pass valve fully, then close the flow control valve of the current or running test section and open the Control Valve of the next test section

Closing Procedure

• Close all Manometers Pressure Taps first when the experiment has been completed
• Switch off the Pump, and the Power Supply to the Panel

Standard Data

• Area of measuring tank (A) = 0.1 m²
• Specific gravity of Hg (s) = 13.6
• Acceleration due to Gravity (g) = 9.81 m/s²

Formulas

• Refer to the original document for diagrams and formulas

Precautions and Maintenance

• Never run the pump at low voltage (i.e. less than 180 Volts).
• Never fully close the Delivery line and By-Pass line Valves simultaneously.
• Always keep apparatus free from dust.
• Run the pump at least once every two weeks to prevent clogging.
• Grease/ Oil the rotating parts frequently, once in every three months
• Always use clean water.
• If the apparatus will not be in use for more than one month, drain it completely and fill the pump with cutting oil.

Troubleshooting

• Manually rotate the shaft by opening the back cover of the pump, if it gets jammed
• Switch off main power for 15 minutes, avoiding closing the flow control valve and bypass valve simultaneously if getting heated.

Lab 3: Losses Due to Pipe Fittings, Sudden Enlargement & Contraction

• The objective is to determine head loss in fittings at various water flow rates and determine the loss coefficient for pipe fittings.
• Head loss from changes in cross-section, bends, elbows, valves, etc., are minor losses in pipe lines. In shorter pipelines their consideration is necessary for correct estimate of losses.

Loss Formulas

• Minor losses in contraction: hL = KL * (V²/2g)
• Minor losses in enlargement: hL = (V1 - V2)² / 2g
• hL = minor loss or head loss
• KL = Loss coefficient
• V1 = velocity of fluid in pipe of small diameter
• V2 = velocity of fluid in pipe of large diameter

Apparatus Description

• The apparatus includes a ½” bend and elbow, sudden expansion from ½” to 1”, sudden contraction from 1” to ½”, ball valve & gate valve.
• Pressure tappings are provided at inlet and outlet of these fittings.
• A differential manometer provides pressure loss readings due to fittings.
• A centrifugal pump supplies water from a sump tank to the pipeline.
• A control valve and bypass valve regulate the flow of water, and discharge is measured using a measuring tank and stopwatch.

Required Utilities:

• Power supply: Single Phase, 220 Volts, 50 Hz, 5 Amp with Earth
• Water Supply
• Drain
• Required space: 1.6 m × 0.6 m

Experimental Procedure (Starting)

• Clean the apparatus and make all tanks free from dust.
• Close the drain valves.
• Fill sump tank with clean water, ensuring that no foreign particles are present.
• Close all Flow Control Valves and open the By-Pass Valve.
• Check the mercury level in the manometer tube and ensure that the On/Off Switch given on the panel is at OFF position
• Switch on the Main Power Supply (220 Volts AC, 50 Hz) and the pump

Experimental Procedure (Operational)

• Operate the Flow Control Valve to regulate flow in desired test section
• Slowly open the Pressure Taps on the Manometer, and air release valves
• Adjust water flow rate in desired section
• Record the Manometer reading.
• Measure the flow of water using Stop Watch and Measuring Tank, and repeat the procedure for different flow rates of water, controlling with the By-Pass valve..

Closing Procedure

• Close all Manometers Pressure Taps first
• Switch off the pump and power supply,

Standard Data

• A = 0.1 m², s = 13.6, g = 9.81 m/s²
• d1 = 0.016 m , d2 = 0.028 m
• a1 = 2.0106 × 10⁻⁴ m², a2 = 6.154 × 10⁻⁴ m²
• 𝚫h = 12.6 × h

Formulae

• hL = KL (V²/2g)
• Refer to document for the rest

Maintenance and Precautions

• Low voltage, never close Delivery line and By-Pass line Valves concurrently, keep clean.
• Prevent clogging, Grease three monthly.
• Always use clean water and drain the machine completely and fill pump with cutting oil if it is unused for a month or more.

Troubleshooting

• Free jammed pumps manually.
• For hot issues, close bypass, switch off, wait 15.

Lab 4: Sedimentation Studies Apparatus

• Objective is to study the batch sedimentation process and to determine effects of initial concentration and initial-suspension height as it relates to sedimentation rates.
• Sedimentation is the process of letting suspended material settle by gravity
• It decreases the velocity of the treated water to a point below which the particle will no longer remain in suspension.
• Colloidal material, small particles cannot settle without coagulation
• Particle shape also effects settling characteristics.
• It is divided into clear zone, partial dense, and dense zones, with the earlier mentioned increasing and then decreasing.
• The shape of the particle also effects its settling characteristics.
• The present experiment involves recording height vs time to plot a graph show various effects.

Setup

• The apparatus consist of 5 borosilicate glass cylinders, a vertical back-panel with back lighting and measuring scales for each of the cylinders.

Required Utilities:

• Electricity Supply requirements
• Weighing Balance: Capacity 2 kg
• Required Chemicals: CaCO3: 2 kg

Experimental Procedure:

• Prepare 5 slurry solutions measuring certain masses of calcium carbonate in water.
• Note the initial height, attach electric supply, switch on light and,
• Manually stir one solution at a time and start the time and,
• Record at 2-5 minute intervals and record the final data.
• Repeat.

Closing Procedure

• Switch off lights, power and clean the cylinders.

Maintenance and Precautions

• Keep dust free, and always drain cylinders after use.

Troubleshooting

• If there are issues, check that the power supply.

Lab 5: Reciprocating Pump Test Rig

General

• Reciprocating pump transfers external mechanical energy into a flowing liquid.
• Positive displacement, liquid is displaced/pushed, drawn from sump, emptied.
• Motion via crank etc, and cylinder stroke moves backwards and forwards.

Cycles

• Plunger stroke creates vacuums on the suction stroke, atmospheric pressure pushes more fluid in. On return, delivery valve opens and pressure forces the fluid into the delivery pipe.
• Double, gives continuity, greater uniformity of flow on the system.

Calculations

• Input is derived via energy meter impulses, compared against time, with a kW/h derivation
• The rps curve is given. Output power is input multiplied by efficiency, and expressed via pgHQ, with constants. Eff % = Water Power over Input power.

Procedure

• Fill, note collecting tank, ensure priming
• Adjust flow control valve for discharge, allowing conditions to steady before the next rate
• Record discharge, suction, etc, reduce flow
• Continue reduction in stages alongside the method

Lab 6: Ostwald's Viscometer

• Determining liquid viscosity relative to methanol.
• Liquid viscosity is the resistance to flow
• Ostwald viscometry measures the fluid as it touches layers
• The measurement is the ratio of absolute fluid viscosity with a specific temperature

Viscosity

• It is applied stress to the rate of straining, a per centimetre value.
• Poiseuielle's Law with laminar:
  • Q = v/t = 𝚫P𝜋r⁴ / 8µL

Standard Values

• Test, distilled water, beaker + equipment and pippet
• Clean and ethanol dry everything before
• Specific levels, immerse in water. Measure values to mark, experiment, then record.
• Repeat and average, experiment to other liquid. Formula example values are also mentioned. (Specific values within, note.)
• It is important that equipment stay clean, and made the proper standard. There need be no air bubble when handling.