MECHANICS OF FLUIDS AND HYDRAULIC MACHINES LAB

Transcription

1 MECHANICS OF FLUIDS AND HYDRAULIC MACHINES LAB DEPARTMENT OF MECHANICAL ENGINEERING PRASHANTH REDDY M [Type the company name]

2 LIST OF EXPERIMENTS S.NO. NAME OF EXPERIMENT 1 IMPACT OF JETS ON VANES (flat, curved,semi sphere) 2 CALIBRATION OF VENTURIMETER 3 CALIBRATION OF ORIFICEMETER 4 FRICTION FACTOR 5 VERIFICATION OF BERNOULIS THEOREM 6 CENTRIFUGAL PUMP 7 RECIPROCATING PUMP TEST RIG 8 FRANCIS TURBINE 9 PELTON WHEEL TURBINE 10 KAPLAN TURBINE 11 MULTI STAGE CENTRIFUGAL PUMP 12 PAGE NO. DATE REMARK SIGN

3 IMPACT OF JETS ON VANES AIM: To determine the Co-efficient of Impact for vanes. APPARATUS: Impact of Jet experimental Set up, stop watch & Vane of different shape (flat and curved) DESCRIPTION: Momentum equation is based on Newton s second law of motion which states that the algebraic sum of external forces applied to control volume of fluid in any direction is equal to the rate of change of momentum in that direction. The external forces include the component of the weight of the fluid & of the forces exerted externally upon the boundary surface of the control volume. If a vertical water jet moving with velocity is made to strike a target, which is free to move in the vertical direction then a force will be exerted on the target by the impact of jet, according to momentum equation this force (which is also equal to the force required to bring back the target in its original position) must be equal to the rate of change of momentum of the jet flow in that direction. PROCEDURE: 1. Fix a required vane (suppose a Flat Plate) to the lever. 2. Adjust the Balancing Weight so that the lever becomes horizontal. 3. Add Known weight to the pan attached to one end of the lever. This will disturb the initial balance of the lever. 4. Start the supply. The jet of water through the nozzle will impinge on the vane. The force due to impact of water will be acting on the vane in the upward direction. 5. Adjust the Supply valve so that the lever will be back to its initial balance. 6. Adjust the weights in the pan and take few more readings. 7. With different vanes attached, and weights, repeat the procedure.

4 DIAGRAM: Nozzle

5 TABULAR COLUMS: S.NO F a (Actual Force in Kg) F t (Theoretical force in Kg) t (Time taken for h cm raise of water in tank) Q= A h t K = F a /F t (coefficient of Impact)

6 CALCULATIONS: F t = ρav 2 (1+cos φ) F a = Load added to the pan ρ= density of the water=1000 kg/m 3 A= area of nozzle V= velocity of jet in m/sec φ= angle made by the jet after impact (0 for flat wane and 135 for curved wane) Q= discharge of water m 3 /sec Q= [Volume of tank / Time taken for h cm raise of water in tank] = [Area of Tank h]/t m 3 /sec Area of tank=50 50 cm 2 Q=area of nozzle velocity of jet = a v m 3 /sec K = Fa Ft Dia of nozzle = 1 cm RESULT: PRECAUTIONS:

7 CLAIBRATION OF VENTURIMETER AIM: To determine the coefficient of discharge of venturi meter. APPARATUS: A pipe provided with inlet and outlet and pressure tapping and venturi in between them, Differential u-tube manometer, Collecting tank with piezometer, Stopwatch, Scale THEORY: Venturi, the Italian engineer, discovered in 1791 that a pressure difference related the rate of flow could be created in pipe by deliberately reducing its area of cross-section. The modern version of the venturi meter was first developed and employed for measurement of flow of water by Clemens Herschel in Venturi meter continues to be the best and most precise instrument for measurement of all types of fluid flow in pipes. The meter consists of a short length of gradual convergence throat and a longer length of gradual divergence. The semi-angle of convergence is 8 to 10 degrees and the semi-angle of divergenceis3 to 5 degrees. By measuring the difference in fluid pressure becore and after throt the flow rate can be obtained from Bernoulli's equation. PROCEDURE: 1. The pipe is selected for doing experiments 2. The motor is switched on, as a result water will flow 3. According to the flow, the ccl4 level fluctuates in the U-tube manometer 4. The reading of H1 and H2 are noted 5. The time taken for 5 cm rise of water in the collecting tank is noted 6. The experiment is repeated for various flow in the same pipe 7. The co-efficient of discharge is calculated

8 SCHEMATIC DIAGRAM: Venturimeter

9 TABULARCOLUMN: S.NO Manometric head Time taken for h cm raise of water h 1 h 2 h w in tank t Theoretical Discharge (Q t ) m 3 /sec Actual Discharge (Q a ) m 3 /sec Coefficient of discharge C d = Q a /Q t

10 CALCULATIONS: t = Time taken for h cm raise of water in tank h 1 = Manometric head in first limb m h 2 = Manometric head in second limb m h w = Venturi head in terms of flowing liquid m = (h 2 -h 1 ) { Specific gravity of ccl 4-1} specific gravity of water Specific gravity of carbontetracloride (ccl 4 ) = 1.6 Specific gravity of water = 1 Diameter of the pipe = 4 cm Diameter of the throat = 2.4 cm Area of collecting tank = cm 2 Theoretical Discharge (Qt) = K h m 3 /sec a1 a2 2g K= a1 2 a2 2 a 1 =area of cross section of pipe a 2 =area of cross section of pipe at throt Actual Discharge (Q a ) = [Volume of water collected in tank/time taken to collect water] = [Area of tank height of water collected in tank]/ t m 3 /sec Coefficient of discharge (C d ) = Q a / Q t RESULT: PRECAUTIONS:

11 CLAIBRATION OF ORIFICEMETER AIM: To determine the coefficient of discharge of orifice meter. APPARATUS: A pipe provided with inlet and outlet and pressure tapping and Orifice in between them, Differential U-tube manometer, Collecting tank with piezometer, Stopwatch, Scale THEORY: An orifice plate is a thin plate with a hole in it, which is usually placed in a pipe. When a fluid passes through the orifice, its pressure builds up slightly upstream of the orifice, but as the fluid is forced to converge to pass through the hole, the velocity increases and the fluid pressure decreases. A little downstream of the orifice the flow reaches its point of maximum convergence, afterd that, the flow expands, the velocity falls and the pressure increases. By measuring the difference in fluid pressure across tappings upstream and downstream of the plate, the flow rate can be obtained from Bernoulli's equation. PROCEDURE: 1. The pipe is selected for doing experiments 2. The motor is switched on, as a result water will flow 3. According to the flow, the ccl4 level fluctuates in the U-tube manometer 4. The reading of H1 and H2 are noted 5. The time taken for 5cm rise of water in the collecting tank is noted 6. The experiment is repeated for various flow in the same pipe 7. The co-efficient of discharge is calculated

12 SCHEMATIC DIAGRAM: Orifice meter

13 TABULARCOLUMN: S.NO Manometric head Time taken for h cm raise of water h 1 h 2 h w in tank t Theoretical Discharge (Q t ) m 3 /sec Actual Discharge (Q a ) m 3 /sec Coefficient of discharge C d = Q a /Q t

14 CALCULATIONS: t = Time taken for h cm raise of water in tank h 1 = Manometric head in first limb m h 2 = Manometric head in second limb m h w = Venturi head in terms of flowing liquid m = (h 2 -h 1 ) { Specific gravity of ccl 4-1} specific gravity of water Specific gravity of carbontetracloride (ccl 4 ) = 1.6 Specific gravity of water = 1 Diameter of the pipe = 4 cm Diameter of the throat = 2.4 cm Area of collecting tank = cm 2 Theoretical Discharge (Qt) = K h m 3 /sec a1 a2 2g K= a1 2 a2 2 a 1 =area of cross section of pipe a 2 =area of cross section of pipe at throt Actual Discharge (Q a ) = [Volume of water collected in tank/time taken to collect water] = [Area of tank height of water collected in tank]/ t Coefficient of discharge C d = Q a /Q t RESULT: PRECAUTIONS:

15 FRICTION FACTOR AIM: To determine the Darcy's friction factor (f) of the given pipe APPARATUS: A pipe provided with inlet and outlet and pressure tapping, Differential u-tube manometer, collecting tank with piezometer, Stopwatch, Scale. DESCRIPTION: When the fluid flows through a pipe the viscosity of the fluid and the inner surface of the pipe offer resistance to the flow. In overcoming the resistance some energy of the flowing fluid is lost. This is called the major loss in pipe flow. Boundary roughness, which has little significance in laminar flow, plays an important role in turbulence. This, together with transverse momentum exchange of fluid particles due to the perpetual turbulent intermixing, are the main sources of tangential or shear stresses in turbulent flow. Various equations have been proposed to determine the head losses due to friction. These equations relate the friction losses to physical characteristics of the pipe and various flow parameters. PROCEDURE: 1. The pipe is selected for doing experiments 2. The motor is switched on, as a result water will flow 3. According to the flow, the mercury level fluctuates in the U-tube manometer 4. The reading of H1 and H2 are noted 5. The time taken for 5cm rise of water in the collecting tank is noted 6. The experiment is repeated for various flow in the same pipe 7. The co-efficient of discharge is calculated

16 SCHEMATIC DIAGRAM:

17 TABULARCOLUMN: S.NO Manometric head Time taken for h cm raise of water h 1 h 2 h f in tank t sec Discharge (Q) m 3 /sec Velocity (v) m/sec Friction factor (f)

18 CALCULATIONS: Friction factor (f) = 2 x g x D x hf Where, l x v2 g = Acceleration due to gravity (m / sec 2 ) cross sectional area D for circular pipe =4x =4x πr2 =d wetted perimeter πd d= Diameter of the pipe = 2cm D for squarer pipe = 4x cross sectional area wetted perimeter =4x wxh 2x w+h w= width of pipe, h= height of pipe l = Length of the pipe = 200cm v = Velocity of liquid following in the pipe (m / s) h f = Loss of head due to friction (m) = (h 2 -h 1 ) { Specific gravity of Hg specific gravity of water - 1} Where h 1 = Manometric head in the first limbs h 2 = Manometric head in the second limbs Actual Discharge Q = A x h Also t (m 3 / sec) Where A = Area of the collecting tank (m 2 ) h = Rise of water for 5 cm (m) t = Time taken for 5 cm rise (sec) Q=Velocity in the pipe X Area of the pipe = v x a v= Q/a RESULT: PRECAUTIONS:

19 VERIFICATION OF BERNOULIS THEOREM AIM: To verify the Bernoulli s theorem. APPARATUS: A supply tank of water, a tapered inclined pipe fitted with no. of piezometer tubes point, measuring tank, scale, and stop watch. THEORY: Bernoulli s theorem states that when there is a continues connection between the particle of flowing mass liquid, the total energy of any sector of flow will remain same provided there is no reduction or addition at any point. I.e. sum of pressure head and velocity head is constant. PROCEDURE: 1. Open the inlet valve slowly and allow the water to flow from the supply tank. 2. Now adjust the flow to get a constant head in the supply tank to make flow in and outflow equal. 3. Under this condition the pressure head will become constant in the piezometer tubes. Note down piezometer readings. 4. Note down the quantity of water collected in the measuring tank for a given interval of time. 5. Compute the area of cross-section under the piezometer tube. 6. Compute the values of velocity head and pressure head. 7. Change the inlet and outlet supply and note the reading. 8. Take at least three readings as described in the above steps.

20 SCHEMATIC DIAGRAM: Throt

21 TABULARCOLUMN: S.NO Pizeometer Reading time for 5cm rise Discharge Q m 3 /sec Pressure Head m Velocity Head m Datum head m Total Head S.NO Pizeometer Reading time for 5cm rise Discharge Q m 3 /sec Pressure Head m Velocity Head m Datum head m Total Head S.NO Pizeometer Reading time for 5cm rise Discharge Q m 3 /sec Pressure Head m Velocity Head m Datum head m Total Head

22 CALCULATIONS: Pressure head = Velocity head P ρg = v2 2g m m Datum head = Z = 0 m (for this experiment) Velocity of water flow = v Q (Discharge) = [Volume of water collected in tank/time taken to collect water] = [Area of tank height of water collected in tank]/ t m 3 /sec Also Q= velocity of water in pipe area of cross section = v A x m 3 /sec Area of cross section (A x ) = A t + [ (Ai At) Ln ] m 2 A t = Area of Throt A i = Area of Inlet Dia of throt = 25mm Dia of inlet = 50mm L n = distance between throt and corresponding pizeometer L=length of the diverging duct or converging duct = 300mm Distance between each piezometer = 75mm L Total Head = P + v2 + Z ρg 2g RESULT: PRECAUTIONS:

23 CENTRIFUGAL PUMP AIM: To study the performance characteristics of a centrifugal pump APPARATUS: 1. centrifugal pump test setup 2. stop watch DESCRIPTION: The operation of filling water in the suction pipe casing and a portion delivery pipe for the removal of air before starting is called priming. After priming the impeller is rotated by a prime mover. The rotating vane gives a centrifugal head to the pump. When the pump attains a constant speed, the delivery valve is gradually opened. The water flows in a radially outward direction. Then, it leaves the vanes at the outer circumference with a high velocity and pressure. Now kinetic energy is gradually converted in to pressure energy. The high-pressure water is through the delivery pipe to the required height. PROCEDURE: 1) Prime the pump, close the delivery valve and switch on the unit. 2) Open the delivery valve and maintain required head. Note the reading of pressure gauge. 3) Note the corresponding reading from vacuum gauge. 4) Measure the area of the collecting tank 5) Close the drain valve and note the time for 10 cm rise of water level in the collecting tank. 6) For different delivery head repeat the experiment. 7) For every set of reading note the time taken for 3 rev. Energy meter.

24 SCHEMATIC DIAGRAM: Centrifugal pump

25 TABULARCOLUMN: S.NO Pressure gauge reading P d (Kg/cm 2 ) Vacuum gauge reading mm of Hg(P s ) Time for 3 rev of Energy meter seconds (t e ) Time for 10 cm rise in collecting tank (t) seconds Discharge (Q) m 3 /sec Input Power P i Output Power P o η%

26 CALCULATIONS: 1. The total effective head H in meters of water column = H d + H s + Z * since the delivery pressure is in Kg/cm 2 and suction gauge readings are in mm of Hg, the total head developed by the pump to be converted in meters of water column. Where H d = delivery head = P d /ρ kg/cm 2 H s = suction head= Ps mm of Hg ρ Z= datum level difference = 2.8 m Note: the velocity head and the loss of the head in the suction pipe are neglected. 2. Knowing the discharge Q = A h t m 3 /sec. Where A = Area of the collecting tank (m 2 ) = 70 X 70 cm 2 h = 10 cm rise of water level in the collecting tank t = Time taken for 10 cm rise of water level in collecting tank. 2. The work done by the pump is given by P o = ρ g Q H 1000 Kw Where, ρ = Density of water = 1000 (kg / m³) g = Acceleration due to gravity = 9.81 (m / s 2 ) H = Total head of water (m) H = suction head (Hs) + delivery Head (H d ) + Datum Head 3. The input power P i = 3600 Nr E te Where N r = Number of revolutions of energy meter disc E = Energy meter constant = 150 T = time taken for Nr revolutions (seconds) 4. The efficiency of the pump = (P o / P i ) 100 % Kw (rev / Kw hr)

27 GRAPH: 1. Actual discharge Vs Total head 2. Actual discharge Vs Efficiency 3. Actual discharge Vs Input power 4. Actual discharge Vs Output power RESULT: PRECAUTIONS:

28 RECIPROCATING PUMP TEST RIG AIM: To study the characteristics of Reciprocating pump. APPARATUS: 1) Reciprocating pump test setup 2) Stop watch DESCRIPTION: Reciprocating pumps also classified as positive displacement pumps as a definite volume of liquid is trapped in a chamber which is alternatively filled from the inlet and emptied at a higher pressure through the discharge. Most piston pumps are acting with liquid admitted alternatively on each side of the piston so that one part of the cylinder is being filled while the other is being emptied to minimize fluctuations in the discharge. It consists of a double action Reciprocating pump of size mm with air vessel coupled to a 1 HP, 1440 rpm single phase motor, piping system consisting of pipes, gate valve, foot valve, pressure and vacuum gauges. Collecting tank with gauge glass scale fittings and drain valve. Panel with switch, starter and energy meter. PROCEDURE: 1. Keep the delivery valve open and switch on the pump. Slowly close the delivery valve and maintain a constant head. 2. Note the delivery and suction gauge reading. 3. Note the time for 10 rev of Energy meter. 4. Note the time for 10 cm rise in water level in the collecting tank. 5. Note the speed of the pump (N) rpm. 6. Repeat the procedure for various openings of the delivery valves.

29 SCHEMATIC DIAGRAM: Reciprocating pump

30 TABULARCOLUMN: S.NO Pressure gauge reading P d (Kg/cm 2 ) Vacuu m gauge reading mm of Hg(P s ) Time for 3 rev of Energy meter (t e )sec Time for 10 cm rise in collecting tank (t)sec Speed N P rpm Discharge (Q) m 3 /sec Input Power P i Output Power P o η% `

31 CALCULATIONS: Stroke length of the pump (L) = m Bore (d) = 0.04m Piston area (a) = (π/4) (0.04) 2 Area of the collecting tank (A) = 50 X 50 cm 2 N P = speed of mortar in rpm To find the percentage of slip = Qt Qa Q t = theoretical discharge = 2 L a Np 60 Q a = Actual discharge = Q= A h A = Area of the collecting tank t = time for (h) rise in water level. t Qt 100 m/sec m/sec To find the overall efficiency of the pump = P o /P i The input power P i = 3600 N Kw E te Where N = Number of revolutions of energy meter disc E = Energy meter constant = 1600 (rev / Kw hr) T = time taken for Nr revolutions (seconds) Output power P o = ρ g Q H Kw 1000 Where, ρ = Density of water = 1000 (kg / m³) g = Acceleration due to gravity = 9.81 (m / s 2 ) H = Total head of water (m) H = suction head (H s ) + delivery Head (H d ) + Datum Head Where H d = delivery head = P d /ρ kg/cm 2 H s = suction head= Ps ρ 1000 mm of Hg Z= datum level difference = 2.8 m

32 GRAPH: 1. Actual discharge Vs Total head 2. Actual discharge Vs Efficiency 3. Actual discharge Vs Input power 4. Actual discharge Vs Output power RESULT: PRECAUTIONS:

33 FRANCIS TURBINE AIM: To study the characteristic of a Francis turbine. APPARATUS: 1. Francis turbine test setup 2. Tacho meter 3. stop watch STARTING UP: Modern Francis turbine in an inward mixed flow reaction turbine it is a medium head turbine. Hence it required medium quantity of water. The water under pressure from the penstock enters the squirrel casing. The casing completely surrounds the series of fixed vanes. The guides vanes direct the water on to the runner. The water enters the runner of the turbine in the dial direction at outlet and leaves in the axial direction at the inlet of the runner. Thus it is a mixed flow turbine. The unit essentially consists of a spiral casing and rotor assembly with runner shaft and break drum, all mounted on suitable study base frame. An elbow fitted draft tube is provided for the purpose of regaining the kinetic energy from the exit water and also facilitating easy accessibility of the turbine due to its location at higher level than the tail race. A transparent hollow Perspex cylinder is provided in between the draft bend and the casing for the purpose of observation of flow at exit of runner. A rope brake arrangement is provided to load the turbine. The output of the turbine can be controlled by adjusting the guide vanes for which a hand wheel and a suitable link mechanism is provided. The net supply head on the turbine is measured by a pressure and vacuum gauge. Make sure that before starting the pipeline are free from foreign matter. Also note whether all the joints are watertight and leak proof. Prime the pump and start it with closed gate valve. The guide vane in the turbine should also be in the closed position while starting the pump. See that all the ball bearings and bush bearings in the units are properly lubricated. Then slowly open the gate valve situated above the turbine and open the cock fitted to the pressure gauge and see that the pump develops the rated head. If the pump develops the required head, slowly open the turbine guide vanes by rotating the hand wheel (which operates the guide vanes through suitable link mechanism) until the turbine attains the normal rated speed. Run the turbine at the normal speed (1250 rpm) for about one hour and carefully note the following: 1. Operation of the bearings, temperature rise, noise etc. 2. Vibration of the unit.

34 SPECIFICATION: 1. Spiral casing: made of cast iron with smooth inner surface. 2. Runner: made of gunmetal casting designed for efficient operation. Accurately machined and smoothly finished. 3. Guide vane :consists of guide vanes rotating in gunmetal bushes Mechanism operated by hand wheel through a link mechanism. 4. Shaft : stainless steel accurately machined 5. Bearing: one number ball bearing and one number taper roller bearing. 6. Draft tube bend: provided at the exit of the runner with a transparent cylindrical window for observation of flow past the runner to the bend is connected a draft tube of mild steel fabrication. 7. Brake arrangement: consists of a machined and polished cast iron brake drum, cooling water pipes, internal water scoop discharge pipe, spring balances, screw rod, and belt brake arrangement. PROCEDURE: 1. keep the guide vane in full open position and slowly open the gate valve so that the turbine runs at 1200 rpm 2. apply load supply by adjusting the screw rod connected to the belt, for loading the brake drum and tighten the locknut 3. the speed gets reduced open the gate valve to an extent the speed is 1200 rpm 4. note the spring balance reading, pressure gauge reading & manometer reading 5. Repeat the above procedure for different loads & for different guide vane opening. SUPPLY PUMP: 1. Rated head : 20 m 2. Discharge : 2000lpm 3. normal speed : 1440 rpm 4. Power required : 15hp (11.2 Kw) 5. Size of pump : mm 6. Type : centrifugal high speed single suction volute. FRANCIS TURBINE: 1. rated supply head : 15.0 m 2. discharge : 2000lpm 3. rated speed : 1250 rpm 4. unit speed : 51.5 rpm 5. specific speed : 95.5 rpm 6. runner diameter : 150 mm

35 7. no. of guide vanes : 8 8. brake drum diameter : 300 mm FLOW MEASURING UNIT: Size of venturi meter 100 mm Throat diameter for venturi meter 60 mm Manometer Double column deferential type. TABULARCOLUMN: S.no Gate opening Pressure gauge Vacuum pressure Manometer reading Speed of rotation Spring balance P i P o η% h 1 h 2 T 1 T 2

36 SCHEMATIC DIAGRAM: Francis turbine

37 CALCULATIONS: Input power (P i ) = (ρ g Q h) Cd a1 a2 2gH watts Flow rate of water Q = m 3 /sec a1 2 a2 2 d 1 = dia. Of venture inlet = 100 mm d 2 = dia. Of venture throught = 60 mm C d = coefficient of discharge of venturimeter = 0.9 Where a 1 = area of inlet of the venturimeter. a 2 = area of the venturimeter throat. H = h 1 -h 2 [ s1-1] s2 h = Total head of water (m) h = suction head (h s ) + delivery Head (h d ) + Datum Head Where h d = delivery head = P d /ρ kg/cm 2 h s = suction head= Ps ρ 1000 Output power (P o ) = 2π N T watts 60 T = (T 1 -T 2 ) g radi. Of break drum radi. Of break drum = 0.15m N = speed in tacho meter Efficiency of the turbine η m %= P o /P i mm of Hg Electrical efficiency = η e % = p o / P i p o = electrical output = V I watts GRAPHS: 1. speed vs. output power 2. speed vs. efficiency RESULT: PRECAUTIONS:

38 PELTON WHEEL TURBINE AIM: To conduct load test on Pelton wheel turbine and to study the characteristics of pelton wheel turbine. APPARATUS REQUIRED: Venturi meter, Stopwatch, Tachometer, Dead weight. DESCRIPTION: Pelton wheel turbine is an impulse turbine, which is used to act on high loads and for generating electricity. All the available heads are classified in to velocity energy by means of spear and nozzle arrangement. Position of the jet strikes the knife-edge of the buckets with least relative resistances and shocks. While passing along the buckets the velocity of the water is reduced and hence an impulse force is supplied to the cups which in turn are moved and hence shaft is rotated. PROCEDURE: 1. The Pelton wheel turbine is started. 2. All the weight in the hanger is removed. 3. The pressure gauge reading is noted down and it is to be maintained constant for different loads. 4. The Venturi meter readings are noted down. 5. The spring balance reading and speed of the turbine are also noted down. 6. A 5Kg load is put on the hanger, similarly all the corresponding readings are noted down. 7. The experiment is repeated

39 SCHEMATIC DIAGRAM: Pelton Wheel Turbine

40 TABULARCOLUMN: S.no Gate opening Pressure gauge Vacuum pressure Manometer reading Speed of rotation Spring balance P i P o η% h 1 h 2 T 1 T 2 Electrical output Load (kw) Voltage V Current (I) A Speed(N) rpm

41 CALCULATIONS: Input power (P i ) = (ρ g Q h) a1 a2 2gH Flow rate of water Q = C d m 3 /sec a1 2 a2 2 d 1 = dia. Of venture inlet = 65 mm d 2 = dia. Of venture throught = 39 mm C d = coefficient of discharge of venturimeter = 0.9 Where a 1 = area of inlet of the venturimeter. a 2 = area of the venturimeter throat. H= h 1 -h 2 [ s1-1] s2 h = Total head of water (m) h = suction head (h s ) + delivery Head (h d ) + Datum Head Where h d = delivery head = P d /ρ kg/cm 2 h s = suction head= Ps ρ 1000 Output power (P o ) = 2π N T watts 60 T = (T 1 -T 2 ) g radi. Of break drum radi. Of break drum = 0.15m N = speed in tacho meter Efficiency of the turbine η m %= P o /P i W mm of Hg Electrical efficiency = η e % = p o / P i p o = electrical output = V I watts GRAPHS: 1. speed vs. efficiency 2. speed vs. power input 3. speed vs. power out put RESULT: PRECAUTIONS:

42 KAPLAN TURBINE AIM: To study the characteristics of a Kaplan turbine APPARATUS REQUIRED: Venturimeter, Stopwatch, Tachometer, Dead weight. DESCRIPTION: Kaplan turbine is an axial flow reaction turbine used in dams and reservoirs of low height to convert hydraulic energy into mechanical and electrical energy. They are best suited for low heads say from 10m to 5 m. the specific speed ranges from 200 to 1000 The flow through the pipelines into the turbine is measured with the office meter fitted in the pipeline. A mercury manometer is used to measure the pressure difference across the orifice meter. The net pressure difference across the turbine output torque is measured with a pressure gauge and vacuum gauge. The turbine output torque is determined with the rope brake drum. A tachometer is used to measure the rpm. PROCEDURE: 1. Keep the runner vane at require opening 2. Keep the guide vanes at required opening 3. Prime the pump if necessary 4. Close the main sluice valve and they start the pump. 5. Open the sluice valve for the required discharge when the pump motor switches from star to delta mode. 6. Load the turbine by adding weights in the weight hanger. Open the brake drum cooling water gate valve for cooling the brake drum. 7. Measure the turbine rpm with tachometer 8. Note the pressure gauge and vacuum gauge readings 9. Note the orifice meter pressure readings. Repeat the experiments for other loads

43 SCHEMATIC DIAGRAM: Kaplan turbine

44 TABULARCOLUMN: S.no Gate opening Pressure gauge Vacuum pressure Manometer reading Speed of rotation Spring balance P i P o η% h 1 h 2 T 1 T 2 Electrical output Load (kw) Voltage V Current (I) A Speed(N) rpm

45 CALCULATIONS: Input power (P i ) = (ρ g Q h) kw a1 a2 2gH Flow rate of water Q = C d m 3 /sec a1 2 a2 2 d 1 = dia. Of venture inlet = 0.13 m d 2 = dia. Of venture throught = m C d = coefficient of discharge of venturimeter = 0.9 Where a 1 = area of inlet of the venturimeter. a 2 = area of the venturimeter throat. H= h 1 -h 2 [ s1-1] s2 h = Total head of water (m) h = suction head (h s ) + delivery Head (h d ) + Datum Head Where h d = delivery head = P d /ρ kg/cm 2 h s = suction head= Ps ρ 1000 mm of Hg Output power (P o ) = 2π N T 60 T = (T 1 -T 2 ) g radi. Of break drum radi. Of break drum = 0.15 N = speed in tacho meter Efficiency of the turbine η%= P o /P i watts m Electrical efficiency = η e % = p o / P i p o = electrical output = V I watts GRAPHS: 1. speed vs. efficiency 2. speed vs. power input 3. speed vs. power out put RESULT: PRECAUTIONS:

46 MULTI STAGE CENTRIFUGAL PUMP AIM: To study the performance characteristics of a centrifugal pump APPARATUS: 1. centrifugal pump test setup 2. stop watch DESCRIPTION: A centrifugal pump with a single impeller that can develop a differential pressure of more than 150 psi between the suction and the discharge is difficult and costly to design and construct. A more economical approach to developing high pressures with a single centrifugal pump is to include multiple impellers on a common shaft within the same pump casing. Internal channels in the pump casing route the discharge of one impeller to the suction of another impeller. The water enters the pump from the top left and passes through each of the four impellers in series, going from left to right. The water goes from the volute surrounding the discharge of one impeller to the suction of the next impeller. A pump stage is defined as that portion of a centrifugal pump consisting of one impeller and its associated components. Most centrifugal pumps are single-stage pumps, containing only one impeller. A pump containing seven impellers within a single casing would be referred to as a seven-stage pump or, or generally, as a multi-stage pump. PROCEDURE: 1. Prime the pump, close the delivery valve and switch on the unit. 2. Open the delivery valve and maintain required head. Note the reading of pressure gauge. 3. Note the corresponding reading from vacuum gauge. 4. Measure the area of the collecting tank 5. Close the drain valve and note the time for 10 cm rise of water level in the collecting tank. 6. For different delivery head repeat the experiment. 7. For every set of reading note the time taken for 3 rev. Energy meter.

47 SCHEMATIC DIAGRAM: Centrifugal pump

48 TABULARCOLUMN: S. N O Pressure readings h 1 h 2 Pressure gauge reading P d (Kg/cm 2 ) Vacuum gauge reading mm of Hg(P s ) Time for 3 rev of Energy meter seconds (t e ) Discharge (Q) m 3 /sec Input Power P i Output Power P o η%

49 CALCULATIONS: a1 a2 2gH Flow rate of water Q = C d a1 2 a2 2 m 3 /sec d 1 = dia. Of venture inlet = 65 mm d 2 = dia. Of venture throught = 39 mm C d = coefficient of discharge of venturimeter = 0.9 Where a 1 = area of inlet of the venturimeter. a 2 = area of the venturimeter throat. H= h 1 -h 2 [ s1 s2-1] h = Total head of water (m) h = suction head (h s ) + delivery Head (h d ) + Datum Head Where h d = delivery head = P d /ρ kg/cm 2 h s = suction head= Ps mm of Hg ρ The work done by the pump is given by P o = ρ g Q H Where, ρ = Density of water (kg / m³) g = Acceleration due to gravity (m / s 2 ) H = Total head of water (m) 1000 Kw 2. The input power P i = 3600 N E te Kw Where N = Number of revolutions of energy meter disc E = Energy meter constant = 150 (rev / Kw hr) T = time taken for N r revolutions (seconds) 3. The efficiency of the pump = (P o / P i ) 100 %

50 GRAPH: 1. Actual discharge Vs Total head 2. Actual discharge Vs Efficiency 3. Actual discharge Vs Input power 4. Actual discharge Vs Output power RESULT: PRECAUTIONS:

51