DEPARTMENT OF CIVIL ENGINEERING LABORATORY MANUAL

Transcription

1 CE6412-HYDRAULIC ENGINEERING LABORATORY LABORATORY MANUAL REGULATION NADAR SARASWATHI COLLEGE OF ENGG. & TECH., VADAPUDHUPATTI, THENI

2 INDEX NSCET LAB MANUAL S. No Experiment Page No 1. Flow through Rotometer 2. Flow through Venturimeter 3. Flow through Orificemeter 4. Flow through Rectangular Notch 5. Flow through Triangular Notch 6. Flow through Orifice 7. Flow through Mouth Piece 8. Determination of Friction Coefficient in Pipes 9. Determination of Loss Coefficients for Pipe Fittings 10. Flow through Variable Duct Area Bernoulli s Equation 11. Characteristics of Kaplan Turbine 12. Characteristics of Pelton Wheel Turbine 13. Characteristics of Francis Turbine 14. Characteristics of Centrifugal Pump 15. Characteristics of Reciprocating Pump 16. Characteristics of Gear Pump 17. Determination of Metacentric Height 18. Characteristics of Submersible Pump Marks Signature

3 Ex. No. 1 AIM FLOW THROUGH ROTOMETER NSCET LAB MANUAL To find out the coefficient of discharge and percentage of slip of given rotometer. APPARTUS USED Rotometer Collecting tank Stop watch and Scale. FORMULA USED Cd = Q actual / Q theoretical Q actual = Ah / t m 3 /s Q theoretical = Taken from rotometer reading A Area of collecting tank, H 10 cm rise of water t Time taken for 10 cm rise of water in seconds Percentage of Slip = (Q theoretical - Q actual / Q theoretical) x 100 = (1- Cd) x 100 PROCEDURE 1. Keep all the three valves (main flow central valve, fine flow central valve and the primary valve) fully opened. Do the priming and close the prime valve. 2. Start the motor 3. Then open the fine central valve completely and open the main flow central valve partially (65%). 4. Allow the system to run for 3-5 minutes, so that flow of water is obtained. 5. Thus by using main and fine central valves set the required water flow rate at the rotometer (from higher flow to lower flow). 6. The float, which is in the rotometer moves up and down frequently. 7. Set the required flow in the rotometer to required discharge. Note the reading.

4 Tabulation: NSCET LAB MANUAL Roto meter Qth = LPH / Time for 10 Actual flow Co-efficient Percentage SL. Reading (1000 x 60) cm rise of of water of discharge Slip No. LPH cm 3 /s water LPH Cd = Qact / % (Q) in Seconds Qact. Qth (1-Cd) x GRAPH Draw a graph of Q actual Vs Q theoritical

5 8. This is theoretical discharge. 9. Then close the Drain valve completely, note the time taken for rise of 10 cm of water in the collecting tank corresponding to the set range of rotometer. 10. Actual discharge is calculated by using formula AH/t. 11. Coefficient of discharge and percentage of slip is calculated. 12. The above procedure is repeated for 3 or 4 reading. RESULT 1. Coefficient of discharge of given rotometer = 2. Percentage of slip of given rotometer =

6 NSCET LAB MANUAL

7 Ex. No. 2 FLOW THROUGH VENTURIMETER NSCET LAB MANUAL OBJECTIVE THEORY To determine the coefficient (K) of the Venturimeter. Venturimeter is a device, used to measure the discharge of any liquid flowing through a pipe line. The pressure difference between the inlet and the throat of the Venturimeter is recorded using a mercury differential manometer, and the time is recorded for a measured discharge. Where, Theoretical discharge, a1 = Area of inlet a2 = Area of throat 2 2 Q th = a1a2 2gh / a1 a2 h = Venturimeter head in terms of flowing liquids. h = x [(sm / s1) 1] h1= Manometric head in one limb of the manometer. h2 = Manometric head in other limb of the manometer. Sm = specific gravity of manometric liquid = 13.6 (mercury) S1 = specific gravity of flowing liquid = 1 (water) g = Acceleration due to gravity Qa = Ah/t where,qa = Actual discharge A = Internal Plan Area of collecting tank h = Rise of liquid t = Time of collection K = Qa/Qth Where, K = Coefficient of Orifice meter Qa = Actual discharge Qth= Theoretical discharge

8 OBSERVATION AND TABULATION NSCET LAB MANUAL Manometric Readings (c m) Discharge(m 3 /s) Of mercury h = 12.6 x Co-efficient of SL. Time for Theoretical Actual Venturimeter No. x = h1 h2 in cm H=10 cm Q th = Q a =AH K = Q a /Q t h1- h2 Rise, t (s) a1a2 (2gh) t 2 (a1 2 a2 ) Area of inlet a1 = πd1 2 / 4 = Area of throat a2 = a1 x 0.35 = Internal plan area of collecting tank, A = 1x b = Actual discharge, Q a = AH/t Theoretical Discharge, Q t = a1a2 (2gh) = (a1 2 a2 2 ) Co-efficient of Venturi meter K = Q a / Qt = GRAPH Graph Q a Vs h and Q a Vs h are drawn taking h and h on X- axis. APPARATUS USED

9 1. A Venturimeter 2. Differential U-Tube mercury manometer 3. Collecting tank, fitted with piezometer and control valve 4. Stop watch 5. Metre scale. PROCEDURE 1. The diameters of the inlet and the throat are recorded and the internal plandimensions of the collecting tank are measured. 2. Keeping the outlet valve closed, the inlet valve is opened fully. 3. The outlet valve is opened slightly and the manometric heads in both the limbs (h1 and h2) are noted. 4. The outlet valve of the collecting tank is closed tightly and the time `t` required for `H` rise of water in the collecting tank is observed using a stop watch. 5. The above procedure is repeated by gradually increasing the flow and observing the required readings. RESULT Coefficient of Venturimeter, k =

10 Ex. No. 3

11 FLOW THROUGH ORIFICEMETER NSCET LAB MANUAL OBJECTIVE To determine the coefficient (K) of the orifice meter. THEORY Orifice meter is a device, used to measure the discharge of any liquid flowing through a pipe line. The pressure difference between the inlet and diaphragm of the orifice meter is recorded using a mercury differential manometer, and the time is Recorded for a measured discharge. Where, Theoretical discharge, a1 = Area of inlet a2 = Area of orifice x = (h1 h2) Q th = a1a2 (2gh) / (a1 2 a2 2 ) h = Differential head in terms of flowing liquids. = x [(Sm/S1)-1] = x [(13.6/1)-1] = 12.6 x. h1 = Manometric head in one limb of the manometer. h2 = Manometric head in other limb of the manometer. Sm = specific gravity of manometric liquid = 13.6 (mercury) S1 = specific gravity of flowing liquid = 1 (water) g = Acceleration due to gravity Qa = Ah/t where, Qa = Actual discharge A = Internal Plan Area of collecting tank h = Rise of liquid t = Time of collection K = Qa/Qth OBSERVATION AND TABULATION

12 SL. No. Manometric Readings (cm) Of mercury x = h1 h2 h1- h2 h = 12.6 x in cm Discharge(cm 3 /s) Co-efficient of Time for Theoretical Actual Orifice meter H=10cm Q th = Q a =AH K = Q a /Q t Rise,t (s) a1a2 (2gh) t (a1 2 a2 2 ) Dimension of the collecting tank, l = b = Model Calculation Reading No = Diameter of inlet pipe = Area of inlet a1 πd1 2 / 4 = Area of throat a2 a1 x 0.45 = Internal plan area of collecting tank, A = lx b = Actual discharge, Q a = AH t Theoretical Discharge, Q t = a1a2 (2gh) = (a1 2 a2 2 ) Co-efficient of Orifice meter K = Q a / Q t = GRAPH Graph Q a Vs h and Q a Vs h are draw taking h and h on X- axis.

13 Where, K = Coefficient of Orifice meter Qa = Actual discharge Qt = Theoretical discharge NSCET LAB MANUAL APPARATUS USED An orifice meter Differential U-Tube mercury manometer Collecting tank fitted with piezometer and control valve Stop watch Metre scale. PROCEDURE 1. The diameters of the inlet and the orifice are recorded and the internal plan dimensions of the collecting tank are measured. 2. Keeping the outlet valve closed, the inlet valve is opened fully. 3. The outlet valve is opened slightly and the manometric heads in both the limbs (h1 and h2) are noted. 4. The outlet valve of the collecting tank is closed tightly and the time `t` required for `H` rise of water in the collecting tank is observed using a stop watch. 5. The above procedure is repeated by gradually increasing the flow and observing the required readings. 6. The observations are tabulated and the coefficient of the orifice meter computed. RESULT Coefficient of Orifice meter, k =

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15 Ex. No. 4 OBJECTIVES FLOW THROUGH RECTANGULAR NOTCH To determine the coefficients of discharge of the rectangular notches APPARATUS REQUIRED Hydraulic bench Notches Rectangular, Hook and point gauge Calibrated collecting tank Stop watch THEORY NSCET LAB MANUAL 1. In open channel hydraulics, weirs are commonly used to either regulate or to measure the volumetricflow rate. 2. They are of particular use in large scale situations such as irrigation schemes, canals and rivers. 3. For small scale applications, weirs are often referred to as notches and invariably are sharp edged andmanufactured from thin plate material. 4. Water enters the stilling baffles which calms the flow. 5. Then, the flowpasses into the channel and flows over a sharp-edged notch set at the other end of the channel. 6. Water comesof the channel in the form of a nappe is then directed into the calibrated collection tank. 7. The volumetric flow rate is measured by recording the time taken to collect a known volume of water in the tank. 8. A vertical hook and point gauge,mounted over the channel is used tomeasure the head of the flow above the crest of the notch.

16 OBSERVATION NSCET LAB MANUAL breadth of the rectangular notch= Area of collecting tank(a)= TABULATION Hook Gauge Head H 3/2 Time Q act = Q th = Co- Reading in m Over taken for Ay/t 2L 2gh efficient Sill Final Sill y cm of Level head H=H 1 - rise in discharge in m H 1 gauge H 2 tank (s) C d =Q a /Q th in m H 2 GRAPH Head Over Sill Vs Q act, Head Over Sill Vs C d

17 Q a =Ah/t m3/s Theoretical discharge Q t =2/3 2gh.H 3/2. m 3 /s NSCET LAB MANUAL Co efficient of discharge Cd= Q a / Q t PROCEDURE 1. Insert the givennotch into the hydraulic bench and fit tightly by using boltsin order to prevent leakage. 2. Open the water supply and allow water till over flowsover the notch.stop water supply, let excess waterdrain through notch and note the initial reading of the water level h using the hook and point gauge. 3. Let water drain from collecting tank and shut the valve of collecting tank after emptying the collectingtank. 4. After initial preparation, open regulating valve to increase the flow and maintain water level over notch.wait until flow is steady. 5. Move hook and point gauge vertically and measure the current waterlevel h1 to find the water head H above the crest of the notch. 6. Note the piezometric reading z0 in the collecting tank while switch on the stopwatch. 7. Record the time taken T and the piezometric reading z1 in the collecting tank after allowing sufficientwater quantity of water in thecollecting tank. 8. Repeat step 3 to step 6 by using different flow rate of water, which can be done by adjusting the water supply. Measure and record the H, the time and piezometric reading in the collecting tank until sets of data have been taken. If collecting tank is full, just empty it. RESULT Co efficient of discharge on Rectangular Notch Cd=

18 Ex. No. 5

19 AIM FLOW THROUGH TRIANGULAR NOTCH To determine the coefficients of discharge of the triangular and notch APPARATUS REQUIRED Hydraulic bench Notches Rectangular, triangular, Hook and point gauge Calibrated collecting tank Stop watch FORMULA Actual discharge Q a =Ah/t m3/s Theoretical discharge Q t =8/15 2g.H 5/2 tanǿ/2. m3/s Co efficient of discharge Cd= Q a / Q t PROCEDURE NSCET LAB MANUAL 1. Insert the given notch into the hydraulic bench and fit tightly by using boltsin order to prevent leakage. 2. Open the water supply and allow water till over flowsover the notch. Stop water supply, let excesswater drain through notch and note the initial reading of the water level h0 using the hook and point gauge. 3. Let water drain from collecting tank and shut the valve of collecting tank after emptying the collecting tank. 4. After initial preparation, open regulating valve to increase the flow and maintain water level over notch.wait until flow is steady. 5. Move hook and point gauge vertically and measure the current water level h1 to find the water head H above the crest of the notch. 6. Note the piezometric reading z0 in the collecting tank while switch on the stopwatch. 7. Record the time taken T and the piezometric reading z1 in the collecting tank after allowing sufficientwater quantity of water in the collecting tank. OBSREVATION

20 Area of the collecting tank A= NSCET LAB MANUAL Angle of the Vnotch = 60 TABULATION Hook Gauge Head H 3/2 Time Q act = Q th = Co- Reading in m Over taken for Ay/t 8/15 2g. efficient Sill Level in Final head Sill H=H 1 - y rise cm in H 5/2 tanǿ/2. m3/s of discharge m H 1 gauge H 2 tank (s) C d =Q a /Q th in m H 2 GRAPH h Vs Q act h Vs C d

21 RESULT Co efficient of discharge on Triangular notch Cd=

22 Ex. No. 6 AIM FLOW THROUGH ORIFICE

23 To determine the co-efficient of discharge of the Orifice by constant head method. APPARATUS REQUIRED FORMULA Orifice fitted to orifice tank Collecting tank fitted with piezometer Calipers Stop watch Meter Scale Actual discharge, Qa = Ah/t m 3 /s where, Qa = Actual discharge A = Internal Plan Area of collecting tank h = Rise of liquid t = Time of collection Theoretical discharge, Q t = a 2gh m 3 /s A = Area of Orifice = 2 d1 / 4 d = Diameter of orifice (m), h = head (m) Co efficient of discharge Cd= Q a / Q t PROCEDURE 1. The diameter of the orifice and the internal dimensions of the collection tank are measured. 2. The supply valve to the storage tank is regulated and water flow controlled so that water level becomes constant at a head, h in m. 3. The outer valve of the collecting tank is tightly closed and the time required for y cm rise of water in the collecting tank is noted using stop watch. OBSERVATIONS AND TABULATION Head in m h Time taken Qa = Ah/t Q t = a 2gh Cd= Q a / Q t for y cm m 3 /s m 3 /s

24 rise in s NSCET LAB MANUAL GRAPH h Vs Q act h Vs C d 4. The above procedure is repeated for different heads and the observations are tabulated.

25 RESULT The value of co-efficient of discharge of Orifice by Constant head method, C d =

26 Ex. No. 7 FLOW THROUGH MOUTH PIECE AIM To determine the co-efficient of discharge of the mouth piece by constant head method.

27 APPARATUS REQUIRED NSCET LAB MANUAL Mouth Piece fitted to mouth piece tank Collecting tank fitted with piezometer Calipers FORMULA Stop watch Meter Scale Actual discharge, Qa = Ah/t m 3 /s where, Qa = Actual discharge A = Internal Plan Area of collecting tank h = Rise of liquid t = Time of collection Theoretical discharge, Q t = a 2gh m 3 /s A = Area of mouth piece = 2 d1 / 4 (m 2 ) d = Diameter of mouth piece (m), h = head (m) Co efficient of discharge Cd= Q a / Q t PROCEDURE 1. The diameter of the mouth piece and the internal dimensions of the collection tank are measured. 2. The supply valve to the storage tank is regulated and water flow controlled so that water level becomes constant at a head, h in m. 3. The outer valve of the collecting tank is tightly closed and the time required for y cm rise of water in the collecting tank is noted using stop watch. OBSERVATIONS AND TABULATION Head in h Time taken Qa = Ah/t Q t = a 2gh Cd= Q a / Q t m for y com m 3 /s m 3 /s rise in s

28 GRAPH h Vs Q act h Vs C d 4. The above procedure is repeated for different heads and the observations are tabulated.

29 RESULT The value of co-efficient of discharge of mouth piece by Constant head method, C d =

30 Ex. No. 8 DETERMINATION OF FRICTION COEFFICIENT IN PIPES (MAJOR LOSSES) OBJECTIVE To determine the friction factor (f) of the given pipe.

31 THEORY NSCET LAB MANUAL When liquid flows through a pipe line, it is subjected to frictional resistance. The friction resistance depends upon the roughness of the inner surface of the pipe. More the roughness, greater is the frictional resistance. discharge. The loss of head between a selected length of pipe is observed for a measured The friction factor (f) is calculated by using the expression. hf =flv 2 / 2gd Where, hf= Loss of head due to friction h = (h1 h2) h [(Sm / S1) 1] = 12.6 h h1 = Manometric head in one limb of the manometer. h2 = Manometric head in other limb of the manometer. Sm = Specific gravity of manometeric liquid = 13.6 (mercury) S1 = Specific gravity of flowing liquid = 1 (water) f = Friction factor L = Length of pipe (between the pressure tapping cocks). V = Velocity of flow in the pipe OBSERVATION AND TABULATION S. Manometric Reading h f = 12.6 Time Q = Velocity Friction No h 1 h 2 h = h 1 x h (m) taken for Ah /t V= Q/a factor h 2 y cm rise (m 3 / m/s f = 2gd

32 in the tank s) h f / lv 2 Dimensions of the collecting tank, l = cm; b = Cross sectional area of pipe, a = d 2 / 4 Internal plan area of collecting tank, A = l x b Actual discharge, Qa = AH / t Velocity, V = Q /a Frictional factor = f = 2gdh / Lv 2 GRAPH hf Vs V Qa = AH / t A = internal plan area of collecting tank. H = Height of collection in the collecting tank. t = Time of collection for H rise in the collecting tank. Velocity, v = Q / a

33 a = Cross sectional area of pipe. d = Diameter of pipe. g = Acceleration due to gravity APPARATUS USED A pipe provided with inlet and outlet valves and tapping cocks. Differential U-Tube mercury manometer Collecting tank fitted with piezometer and control valve Stop watch Meter scale. PROCEDURE 1. The diameter of the pipe is measured and the internal plan dimensions of the collecting tank and the length of the pipeline between the two pressure tapping cocks are measured. 2. Keeping the outlet valve closed, the inlet valve is opened fully. 3. The outlet valve is opened slightly and the manometric heads in both the limbs (h1 and h2) are noted. 4. The outlet valve of the collecting tank is closed tightly and the time `t` required for `H` rise of water in the collecting tank is observed using a stop watch. 5. The above procedure is repeated by gradually increasing the flow and observing the required readings. 6. The observations are tabulated and the friction factor computed. RESULT Friction factor of the given pipe, f =

34 Ex. No. 9 DETERMINATION OF LOSS COEFFICIENTS FOR PIPE FITTINGS (MINOR LOSSES) AIM

35 To determine the co-efficient of contraction of the given pipe. APPARATUS REQUIRED Differential U tube manometer Collecting tank fitted with piezometer Stop watch Meter Scale FORMULA h = (h1 h2) h [(Sm / S1) 1] = 12.6 h where, h1 = Manometric head in one limb of the manometer. h2 = Manometric head in other limb of the manometer. Sm = Specific gravity of manometeric liquid = 13.6 (mercury) S1 = Specific gravity of flowing liquid = 1 (water) Qa = AH / t Where, A = internal plan area of collecting tank. H = Height of collection in the collecting tank. t = Time of collection for H rise in the collecting tank. Velocity, v = Q / a a = Cross sectional area of pipe. d = Diameter of pipe. g = Acceleration due to gravity OBSERVATION AND TABULATION S. No Manometric Reading h f = Time h 1 h 2 h = h x taken for h 2 h (m) y cm rise in Velocity Q V= Q/a =Ah m/s /t (m 3 / Sudden Contraction C c = V / [V +

36 the tank s) (2gh f )] GRAPH V Vs h f h f = loss of head in m of water. Sudden Contraction C c = V / [V + (2gh f )] PROCEDURE

37 1. The system details of the equipment are noted down pertaining to the experiment. Eg. Diameter of the smaller pipe, size of the collecting tank. 2. The flow is admitted into the pipe by opening the inlet valve. 3. The manometer is flushed by operating the manometric stop cocks. 4. After flushing, the manometer stop clocks are set to read position. 5. The left limb and right limb readings of the manometer are noted. 6. The exit value of the collecting tanks is closed and the time taken for 10 cm rise of water is noted using a stop watch. 7. The step 5 and 6 are repeated by varying the inlet valve opening i.e varying the discharge. 8. The outlet of the collecting tank is opened immediately after taking the reading to avoid overflow of the tank. 9. After sufficient readings are taken the inlet valve is closed. 10. The observations are tabulated. RESULT The value of sudden contraction, C c =

38 Ex. No. 10 FLOW THROUGH VARIABLE DUCT AREA-BERNOULLI S EXPERIMENT AIM

39 To verify the Bernoulli s theorem. APPARATUS USED A supply tank of water a tapered inclined pipe fitted with number of piezometer tubes point Measuring Tank Scale Stop Watch. THEORY Bernoulli s theorem states that when there is a continues connection between the particle of flowingmass liquid, the total energy of any sector of flow will remain same provided there is no reduction or addition at any point. FORMULA USED H 1 = Z 1 + p 1 /w + V 2 1 /2g H 2 = Z 2 + p 2 /w + V 2 2 /2g 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 out flow equal. 3. Under this condition the pressure head will become constant in the piezometer tubes. 4. Measure the heads at all the points. 5. Note down the quantity of water collected in the measuring tank for a given interval of time. 6. Vary the discharge and repeat the procedure TABULATION S. No Tube No Radius Area of flow A (m 2 ) Discharge Q (m 3 /s) Velocity V (m/s) Velocity Head (m) Pressur e Head (m) Total Head (m)

40 NSCET LAB MANUAL

41 RESULT Hence the Bernoulli s theorem is verified.

42 Ex. No. 11 CHARACTERISTICS OF KAPLAN TURBINE AIM To study the performance characteristics of Kaplan Turbine and to draw the characteristic curves. THEORY The Kaplan turbine is a propeller-type water turbine which has adjustable blades. It

43 was developed in 1913, combined automatically adjusted propeller blades with automatically adjusted wicket gates to achieve efficiency over a wide range of flow and water level. The Kaplan turbine is an inward flow reaction turbine, which means that the working fluid changes pressure as it moves through the turbine and gives up its energy. Power is recovered from both the hydrostatic head and from the kinetic energy of the flowing water. The design combine features of radial and axial turbines. The inlet is a scroll-shaped tube that wraps around the turbine s wicket gate. Water is directed tangentially through the wicket gate and spirals on to a propeller shaped runner, causing it to spin. The outlet is a specially shaped draft tube that helps decelerate the water and recover kinetic energy. The turbine does not need to be at the lowest point of water flow as long as the draft tube remains full of water. A higher turbine location, however, i ncreases the suction that is imparted on the turbine blades by the draft tube. The resulting pressure drop may lead to cavitations. Variable geometry of the wicket gate and turbine blades allows efficient operation for a range of flow conditions. Kaplan turbine efficiencies are typically over 90% but may be lower in very low head applications. OBSERVATION AND TABULATION Po Pi Ƞ

44 Net Weight W T N NSCET LAB MANUAL h1 h2 H = h1 - h2 W1 W2 S. No Manometer Reading No. at load Discharge, Q Vacuum Gauge Kg watt Pressure Gauge Kg / cm 2 water Total Hea d H APPARATUS REQUIRED Pelton Wheel Supply Pump Venturimeter fitted with differential manometer Rope brake dynamo meter Tachometer Pressure gauge

45 Set of weighs FORMULA Discharge, Q = a 1 a 2 2gh / (a a 2 2 ) a 1 = Area of pipe in sq. m a 2 = Area of throat in sq. m h = Manometric head in m. Input Power, P i = wqh Nm/s H = Total head w = 9.81 x 10 3 Torque, T = 9.81 x W x Re Re = Reynold Number Output Power, P o = 2πNT / 60 N = Speed of shaft Efficiency, NSCET LAB MANUAL Ƞ = P o / P i GRAPH Discharge Vs Efficiency Discharge Vs Output Power Discharge Vs Input Power Discharge Vs Head

46 PROCEDURE Constant speed 800rpm 1. The supply pump is first started with the discharge valve completely closed. 2. The head is adjusted to be 30 m of water by fully opening the gate (18 turns) 3. The loads on the brake drum are adjusted to get the constant speed of 800 rpm and the following readings are taken. a. Pressure gauge reading (H) b. Manometer reading (h 1 and h 2 )

47 c. Speed of the shaft (N) d. Dead weight on the load hanger 4. Subsequent set of above readings are taken and tabulated for various gate openings and varying the brake loads for constant speed of 800 rpm Constant head (30 m) Full gate opening 1. The supply pump is first started with the discharge valve completely closed. 2. The gate valve is fully opened and the head on the water supplied to the turbine is adjusted to 30 m of water by regulating the discharge valve. 3. The dead loads on the brake are adjusted for 600 rpm and the following are taken a. Pressure gauge reading (H) b. Manometer reading (h 1 and h 2 ) c. Speed of the shaft (N) d. Dead weight on the load hanger 4. The dead loads on the brake are adjusted for various speeds and the above sets of readings are observed and are tabulated. RESULT Thus the characteristic curves drawn from the point of maximum efficiency condition 1) Maximum Efficiency = 2) Maximum Output (P o ) = 3) Discharge (Q) =

48 Ex. No. 12 CHARACTERISTICS OF PELTON WHEEL TURBINE AIM To conduct the load test on the given pelton wheel turbine by keeping constant speed and variable gate opening and to draw the characteristic curves. THEORY The pelton wheel turbine has been classified as an impulse turbine, where the available head is wholly converted into velocity energy with approximate zxial flow. It is

49 used for very high heads. It is a most efficient type of impulse turbine. The jet of water impings on the wheel from one or more nozzles and strikes on the buckets. The buckets are of double hemispherical cup shape. The needle nozzle regulates the flow of water. The buckets are so shaped that the jet is discharged backwards. The supply to the turbine is affected by means of a centrifugal pump. An orifice meter measures the discharge. A differential manometer measures the difference in pressure. The pressure gauge at the inlet of the turbine measures the net head supplied by the pump to the turbine. Input power supplied to the turbine is calculated from the net supply head on the turbine and the discharge through turbine. The output power from the turbine is calculated from the readings taken on the shaft. The efficiency of the turbine is computed from the output and the input. APPARATUS REQUIRED Pelton Wheel Supply Pump Venturimeter fitted with differential manometer Rope break dynamo meter Tachometer Pressure gauge Set of weighs OBSERVATION AND TABULATION Pi Po N Ƞ

50 Net Weight W T NSCET LAB MANUAL h1 h2 H = h1 - h2 W1 W2 S. No Manometer Reading No. at load Discharge, Q Vacuum Gauge Kg watt Pressure Gauge Kg / cm 2 water Total Hea d H FORMULA Discharge, Q = a 1 a 2 2gh / (a a 2 2 ) a 1 = Area of pipe in sq. m a 2 = Area of throat in sq. m h = Manometric head in m. Input Power, P i = wqh Nm/s H = Total head

51 w = 9.81 x 10 3 Torque, T = 9.81 x W x Re Re = Reynold Number Output Power, P o = 2πNT / 60 N = Speed of shaft Efficiency, NSCET LAB MANUAL Ƞ = P o / P i PROCEDURE Constant speed 800rpm 1. The supply pump is first started with the discharge valve completely closed. 2. The head is adjusted to be 30 m of water by fully opening the gate (18 turns) 3. The loads on the brake drum are adjusted to get the constant speed of 800 rpm and the following readings are taken. a. Pressure gauge reading (H) b. Manometer reading (h 1 and h 2 ) c. Speed of the shaft (N) d. Dead weight on the load hanger GRAPH Discharge Vs Efficiency Discharge Vs Output Power Discharge Vs Input Power Discharge Vs Head

52 4. Subsequent set of above readings are taken and tabulated for various gate openings and varying the brake loads for constant speed of 800 rpm Constant head (30 m) Full gate opening 1. The supply pump is first started with the discharge valve completely closed. 2. The gate valve is fully opened and the head on the water supplied to the turbine is adjusted to 30 m of water by regulating the discharge valve. 3. The dead loads on the brake are adjusted for 600 rpm and the following are taken a. Pressure gauge reading (H) b. Manometer reading (h 1 and h 2 )

53 c. Speed of the shaft (N) d. Dead weight on the load hanger 4. The dead loads on the brake are adjusted for various speeds and the above sets of readings are observed and are tabulated. RESULT Thus the characteristic curves drawn from the point of maximum efficiency condition 1) Maximum Efficiency = 2) Maximum Output (P o ) = 3) Discharge (Q) =

54 Ex. No. 13 CHARACTERISTICS OF FRANCIS TURBINE AIM To study the performance characteristics of Francis Turbine and to draw the characteristic curves. THEORY The Francis Turbine is a reaction turbine which mixed flow runner. Around the runner, a set of stationery guide vanes directs the water into the moving vanes. The guide vanes also serve as gates. A handle can adjust the gate openings. A chamber called

55 spiral chamber surrounds the guide vanes. On the discharge side, the water passes to the tail race by a tube called draft tube. The draft tube enables the turbine to set as a higher level without turbine to set at a higher level without sacrifice in head. Moreover, it entails regaining of pressure energy, thus increasing the efficiency of the turbine. Pressure gauge and vacuum gauge are set to measure the heads at certain points. The supply to the turbine is affected by means of centrifugal pump. An orifice meter measures the discharge passing into the turbine. A differential manometer measures the difference in pressure. The input power supplied to the turbine is calculated from the net supply head on the turbine and the discharge through the turbine. The output power from the turbine is calculated from the readings taken on the rope brake dynamometer and the speed of the shaft. The efficiency of the turbine is computed from the output and the input. For any particular setting of the middle vanes, first the turbine is run for some time at a light load then the brake loading is increased gradually by adding dead weights on the load hanger. The net supply head on the turbine can be maintained constant at the required value by adjusting the discharge valve of the pump. Francis Wheel Supply Pump Venturimeter fitted with differential manometer Rope break dynamo meter Tachometer OBSERVATION AND TABULATION Pi Po N Ƞ

56 Net Weight W T NSCET LAB MANUAL h1 h2 H = h1 - h2 W1 W2 S. No Manometer Reading No. at load Discharge, Q Vacuum Gauge Kg watt Pressure Gauge Kg / cm 2 water Total Hea d H Pressure gauge Set of weighs FORMULA Discharge, Q = a 1 a 2 2gh / (a a 2 2 ) a 1 = Area of pipe in sq. m a 2 = Area of throat in sq. m h = Manometric head in m. Input Power,

57 P i = wqh Nm/s H = Total head w = 9.81 x 10 3 Torque, T = 9.81 x W x Re Re = Reynold Number Output Power, P o = 2πNT / 60 N = Speed of shaft Efficiency, NSCET LAB MANUAL Ƞ = P o / P i PROCEDURE 1. The supply pump is first started with the discharge valve completely closed. 2. The turbine is adjusted to the requested gate opening by operating the handle. 3. Water is fed into the turbine and the turbine is allowed to run for some time. 4. The rope brake is adjusted for the required speed of the shaft (say 600rpm) and the following sets of readings are taken. a. Speed of the shaft (N) b. Manometer reading (h 1 and h 2 ) c. Pressure gauge reading (H d ) d. Vacuum gauge reading (H s ) GRAPH Discharge Vs Efficiency Discharge Vs Output Power Discharge Vs Input Power Discharge Vs Head

58 e. Height of centre of pressure gauge above the centre of vacuum gauge (x) 5. Note dead weight on load hanger, spring balance readings. 6. Subsequent set of above readings are taken and tabulated by gradually increasing the brake load for different speeds.

59 RESULT Thus the characteristic curves drawn from the point of maximum efficiency condition 1) Maximum Efficiency = 2) Maximum Output (P o ) = 3) Discharge (Q) =

60 Ex. No. 14 CHARACTERISTICS OF CENTRIFUGAL PUMP OBJECTIVE To determine the best driving conditions of the given centrifugal pump of constant speed and to draw the characteristic curves. THEORY A pump is a device, used for lifting liquids from a lower level to a higher level. The pump increases the energy of a liquid in a closed system. It converts mechanical energy into pressure energy. A centrifugal pump derives its name from its centrifugal action. It converts mechanical energy into hydraulic energy.

61 The energy supplied to the pump is measured from an energy meter. The work done by the pump is obtained from the measured discharge and the total lift. The total lift is computed from the observations of the suction gauge, pressure gauge and their relative positions. FORMULA Discharge, Qa = AH/t where, Qa = Actual discharge A = Internal Plan Area of collecting tank H = Rise of liquid = 10 cm t = Time of collection Total head, (H) = Hs +Hd +X Where Hs = Suction head in meters of water. Hd = Delivery head in meters of water X = Difference in level between the centres of vaccum and pressure gauges. OBSERVATIONS & TABULATION Po Pi Q = Ah / t ƞ

62 S. No Suction Head mm of Hs 10-3 x 13.6 of water Delivery Head kg/cm2 kg/cm 2 x 1o m of water Total Head H = Hs + Hd + x Time for h = 10cm rise Time for Nr = 5 revolution NSCET LAB MANUAL Input to the motor, Pi = 3600 x Nr x 1000 / Ne T Where, Ne = Energy meter constant in revolution per KWh. Nr = Number of revolutions of energy meter disc in seconds. T = Time taken for 5 revolutions in the energy meter. Output from the pump, P o = WQH Where, W = unit weight of water 9810 N / m 3 Q = actual discharge m 3 /s H = Total head m

63 Efficiency of the pump (ƞ) = (P o / P i ) x 100 Where, P o = Output Power P i = Input power APPARATUS USED PROCEDURE 1. Centrifugal Pump 2. Collecting Tank 3. Piezometer 4. Metre Scale. 5. Stop Watch 6. Energy Meter 7. Pressure Gauge 8. Vaccum Gauge 9. Driving Unit. 1. The internal plan dimensions of the collecting tank and the difference in level between the centres of vaccum and pressure gauges (x) measured. 2. The speed of the pump and the energy meter constant (Ne) are noted. 3. The pump is primed with water. 4. With the delivery valve fully closed the driving unit is started. 5. By regulating the delivery valve, the discharge and hence the delivery head GRAPH The following grapes are drawn taking Q on X-axis. 1. Discharge (Q) Vs head (H) 2. Discharge (Q) Vs output (Po) 3. Discharge (Q) Vs percentage efficiency (n)

64 are varied. For each position of the delivery valve, from completely closed to maximum open. a. Vaccum gauge reading(hs) b. Pressure gauge reading (Hd) c. Time (T) taken for Nr revolutions of the energy meter disc. d. Time taken for a particular rise (h) of water level in the collecting tank, keeping output valve completely closed. 6. The above observations, for different delivery valve openings, are tabulated. The efficiency of the pump is computed.

65 RESULT The characteristic curves are drawn from the point of maximum efficiency the best driving conditions are found out. The best driving conditions of the pump are obtained when, 1. Discharge (Q) = 2. Head (H) = 3. Output (Po) = 4. Efficiency (n) =

66 Ex. No. 15

67 RECIPROCATING PUMP NSCET LAB MANUAL OBJECTIVE To determine the coefficient of discharge (Ca), Slip (S) and efficiency (η) of the reciprocating pump. THEORY A pump is a device, used for lifting liquids from a lower level to a higher level. The pump increases the pressure energy of a liquid in a closed system. A reciprocating pump derives its name from the reciprocating motion of the piston. By the movement of a piston or a plunger, working inside a cylinder draws the liquid and forces it out of the cylinder. It is otherwise known as positive displacement pump. The energy supplied to the pump is measured from an energy meter. The work done by the pump is obtained from the measured discharge and the total lift. The total lift is computed from the observations of the suction gauge, pressure gauge and their relative positions. FORMULA Discharge, Qa = AH/t where, Qa = Actual discharge A = Internal Plan Area of collecting tank H = Rise of liquid = 10 cm t = Time of collection Total head, (H) = Hs +Hd +X Where Hs = Suction head in meters of water. Hd = Delivery head in meters of water X = Difference in level between the centres of vaccum and pressure gauges. Input to the motor, Pi = 3600 x Nr x 1000 / Ne T OBSERVATIONS & TABULATION

68 Po Pi S. No Suction Head mm of Hs 10-3 x 13.6 of water Delivery Head kg/cm2 kg/cm 2 x 1o m of water Total Head H = Hs + Hd + x Time for h = 10cm rise Time for Nr = 5 revolution Q = Ah / t ƞ Where, Ne = Energy meter constant in revolution per KWh.

69 Nr = Number of revolutions of energy meter disc in seconds. T = Time taken for 5 revolutions in the energy meter. Output from the pump, P o = WQH Where, W = unit weight of water 9810 N / m 3 Q = actual discharge m 3 /s H = Total head m Efficiency of the pump (ƞ) = (P o / P i ) x 100 Where, P o = Output Power P i = Input power APPARATUS USED PROCEDURE 1. Reciprocal Pump 2. Collecting Tank 3. Piezometer 4. Metre Scale. 5. Stop Watch 6. Energy Meter 7. Pressure Gauge 8. Vaccum Gauge 9. Driving Unit. 1. The internal plan dimensions of the collecting tank and the difference in level between the centres of vacuum and pressure gauges (x) are measured. 2. The speed of the pump and the energy meter constant (Ne) are noted. 3. The pump is primed with water. 4. With the delivery valve fully closed the driving unit is started. 5. By regulating the delivery valve, the discharge and hence the delivery head are varied. For each position of the delivery valve, from completely closed to maximum open, the following observations are made GRAPH The following grapes are drawn taking Q on X-axis.

70 Discharge (Q) Vs head (H) Discharge (Q) Vs output (Po) Discharge (Q) Vs percentage efficiency (n) NSCET LAB MANUAL a) Vacuum gauge reading(hs) b) Pressure gauge reading (Hd)

71 c) Time (t) taken for Nr revolutions of the energy meter disc. d) Time taken for a particular rise (h) of water level in the collecting tank, keeping output valve completely closed. 6. The above observations, for different delivery valve openings, are tabulated. The efficiency of the pump is computed. RESULT The characteristic curves are drawn from the point of maximum efficiency the best driving conditions are found out. The best driving conditions of the pump are obtained when, 1. Discharge (Q) = 2. Head (H) = 3. Output (Po) = 4. Efficiency (n) =

72 Ex. No. 16 GEAR PUMP

73 OBJECTIVE THEORY NSCET LAB MANUAL To study the performance and to draw the characteristic curve of gear pump. Although the gear pump which consists of two gears, yet its action on liquid to be pumped is not dynamic and it merely displaces the liquid from one side to the other. However, the flow of liquid to be pumped is continuous and uniform and there is no change of velocity and acceleration under normal stable conditions. This type of pump is widely used for cooling water and pressure oil to be supplied for lubrication to motors, turbines machine tools etc.. The external gear pump in its simplest form consists of two identical intermeshing spur wheels working with a fine clearance inside the casing. The wheels are so designed, that they form a fluid tight joint at the point of contact. One of the wheels is keyed to the driving shaft (rotor) and the other revolves as a driven wheel (idler). The pump is first filled with the liquid to be pumped before it is started. As the gear wheels rotate, the liquid is trapped in between their teeth and flown to the discharge end round the casing. The rotating gears build up sufficient pressure to force the liquid into the delivery pipe. Each tooth of the gear acts like a piston or plunger of on reciprocating pump and hence the pump can be termed a positive displacement pump. FORMULA Discharge, Qa = AH/t where, Qa = Actual discharge A = Internal Plan Area of collecting tank H = Rise of liquid = 10 cm t = Time of collection OBSERVATIONS & TABULATION

74 Po Pi S. No Suction Head mm of Hs 10-3 x 13.6 of water Delivery Head kg/cm2 kg/cm 2 x 1o m of water Total Head H = Hs + Hd + x Time for h = 10cm rise Time for Nr = 5 revolution Q = Ah / t ƞ Total head, (H) = Hs +Hd +X Where

75 Hs = Suction head in meters of water. Hd = Delivery head in meters of water X = Difference in level between the centres of vaccum and pressure gauges. Input to the motor, Pi = 3600 x Nr x 1000 / Ne T Where, Ne = Energy meter constant in revolution per KWh. Nr = Number of revolutions of energy meter disc in seconds. T = Time taken for 5 revolutions in the energy meter. Output from the pump, P o = WQH Where, W = unit weight of water 9810 N / m 3 Q = actual discharge m 3 /s H = Total head m Efficiency of the pump (ƞ) = (P o / P i ) x 100 Where, P o = Output Power P i = Input power APPARATUS USED PROCEDURE 1. Gear Pump 2. Collecting Tank 3. Piezometer 4. Metre Scale. 5. Stop Watch 6. Energy Meter 7. Pressure Gauge 8. Vaccum Gauge 9. Driving Unit. 1. The internal plan dimensions of the collecting tank and the difference in level between the centres of vacuum and pressure gauges (x) are measured. GRAPH The following grapes are drawn taking Q on X-axis.

76 Discharge (Q) Vs head (H) Discharge (Q) Vs output (Po) Discharge (Q) Vs percentage efficiency (n) NSCET LAB MANUAL 2. The speed of the pump and the energy meter constant (Ne) are noted. 3. The pump is primed with water.

77 4. With the delivery valve fully closed the driving unit is started. 5. By regulating the delivery valve, the discharge and hence the delivery head are varied. For each position of the delivery valve, from completely closed to maximum open, the following observations are made a. Vacuum gauge reading(hs) b. Pressure gauge reading (Hd) c. Time (t) taken for Nr revolutions of the energy meter disc. d. Time taken for a particular rise (h) of water level in the collecting tank, keeping output valve completely closed. 6. The above observations, for different delivery valve openings, are tabulated. The efficiency of the pump is computed. RESULT The characteristic curves are drawn from the point of maximum efficiency the best driving conditions are found out. The best driving conditions of the pump are obtained when, 1. Discharge (Q) = 2. Head (H) = 3. Output (Po) = 4. Efficiency (n) =

78 Ex. No. 17 METACENTRIC HEIGHT APPARATUS

79 AIM NSCET LAB MANUAL To determine the metacentric height of a ship model. PROCEDURE 1. Find the weight of the ship without load in a balance. 2. Load the ship with circular loads at the large ship. 3. Keep the larger swinging weight and the smaller in the notch nearer to the mass 2 cm and the smaller in the second notch i.e 4 cm from the most of other side. 4. Note the angle of inclination 5. Note the distance of weight W and X and for smaller weight W2. 6. Repeat the process for 5 different angle of inclination. OBSERVATION AND TABULATION S. No X1 X2 M1 = W1X1 M2 = W2X2 Wx = T ( C) GM = W (cm) (cm) (kg. cm) (kg.cm) M1 M2 / W tan t

80 NSCET LAB MANUAL

81 RESULT The metacentric height of the ship model =

82 Ex. No. 18 CHARACTERISTICS OF SUBMERSIBLE PUMPS

83 ƞ AIM NSCET LAB MANUAL To determine the characteristics of a submersible pump and to draw the performance curves. THEORY Pump devices are used for lifting liquids from a lower level to a higher level. It converts mechanical energy into hydraulic energy. Submersible pump essentially consists of a multi stage set. Each set is made of a mixed flow impeller with axial diffuser assembly. The shaft of the pump is connected to the motor, which is housed on the bottom of the set. The pump and the motor assembly are submerged in water. The energy supplied to the pump is measured using energy meter. The work done by the pump is obtained from the measured discharge and total lift. APPARATUS REQUIRED Submersible pump with driving unit. Stop watch Metre Scale Collecting tank with a piezometer tube FORMULA Q = C d x a1a2 (2gh) / (a1 2 a2 2) Where, a1 = Area of inlet a2 = Area of throat Input to the motor, Pi = 3600 x Nr x 1000 / Ne T Where, Ne = Energy meter constant in revolution per KWh. Nr = Number of revolutions of energy meter disc in seconds. T = Time taken for 5 revolutions in the energy meter. OBSERVATIONS & TABULATION

84 Po Pi S. No Suction Head mm of Hs 10-3 x 13.6 of water Delivery Head kg/cm2 kg/cm 2 x 1o m of water Total Head H = Hs + Hd + x Time for h = 10cm rise Time for Nr = 5 revolution Q = Ah / t Output from the pump, P o = WQH Where, W = unit weight of water 9810 N / m 3 Q = actual discharge m 3 /s

85 H = Total head m Efficiency of the pump (ƞ) = (P o / P i ) x 100 Where, P o = Output Power P i = Input power PROCEDURE 1. The motor is started. 2. The following readings are noted. a. The pressure gauge readings in the delivery side of the pump (Hd). b. The height between the pressure gauge and water level (X). c. Time taken for 3 revolutions in energy meter by means of stopwatch. 3. Take several set of readings, varying the head from maximum to minimum. 4. For various heads input, output and efficiency pump are calculated. GRAPH Discharge Vs Efficiency Discharge Vs head, taking discharge along X-axis.

86 NSCET LAB MANUAL

87 RESULT The characteristic curves are drawn from the point of maximum efficiency the best driving conditions are found out. The best driving conditions of the pump are obtained when, 1. Discharge (Q) = 2. Head (H) = 3. Output (Po) = 4. Efficiency (n) =