FM11 Manual
-
Upload
syafiq-izzuddin -
Category
Documents
-
view
144 -
download
4
description
Transcript of FM11 Manual
Table of content
Pages 1.0 INTRODUCTION ................................................................................................................. 2
2.0 GENERAL DESCRIPTION .................................................................................................. 3 2.1 Unit Assembly ............................................................................................................ 3
3.0 INSTALLATION AND COMMISSIONING ........................................................................... 4
4.0 SUMMARY OF THEORY ..................................................................................................... 5 4.1 Pipe Flow Conditions ................................................................................................. 5 4.2 Laminar Flow ............................................................................................................. 5 4.3 Transitional Flow ........................................................................................................ 5 4.4 Turbulent Flow ........................................................................................................... 5
5.0 EXPERIMENT PROCEDURES............................................................................................ 6 5.1 Experiment A ............................................................................................................. 6 5.2 Experiment B ............................................................................................................. 6 5.3 Data sheet ................................................................................................................. 7
APPENDIX A .................................................................................................................................... 8
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
2
1.0 INTRODUCTION
The SOLTEQ® Osborne Reynold’s Demonstration (Model: FM 11) has been designed for students experiment on the laminar, transition and turbulent flow. It consists of a transparent header tank and flow visualization pipe. The header tank is provided with a diffuser and stilling materials at the bottom to provide a constant head of water to be discharged through a bell mouth entry to the flow visualization pipe. Flow through this pipe is regulated using a control valve at the discharge end. The water flow rate through the pipe can be measured using the volumetric tank (or volumetric cylinder). Velocity of the water can therefore be determined to allow the calculation of the Reynold’s Number. A dye injection system is installed on top of the header tank so that flow pattern in the pipe can be visualized.
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
3
2.0 GENERAL DESCRIPTION
2.1 Unit Assembly
Figure 1: Unit Assembly of Osborne Reynold’s Demonstration (Model: FM11)
1. Dye reservoir 2. Dye injector 3. Head tank 4. Observation tube 5. Water inlet valve, V1 6. Bell mouth 7. Water outlet valve, V2 8. Overflow valve, V3 The Osborne Reynold’s Demonstration apparatus is equipped with a visualization tube for students to observe the flow condition. The rocks inside the stilling tank are to calm the inflow water so that there will not be any turbulence to interfere with the experiment. The water inlet / outlet valve and dye injector are utilized to generate the required flow.
1
2
4
3
5
6
7
8
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
4
3.0 INSTALLATION AND COMMISSIONING
1. Assemble the Osborne Reynold’s as shown in the picture.
2. Place the Osborne Reynold’s apparatus on a level ground. Use a level spirit to level the apparatus.
3. Connect hose to the apparatus outflow, inflow and overflow.
4. Fill up the dye reservoir with the provided blue ink.
5. Establish water supply by connecting the inlet hose to a water source and open the inlet valve.
6. Fill the stilling tank with the aquarium stones that are being provided and proceed to fill up the stilling tank with water.
7. Open the outflow valve to test the unit. Check for any leaking of water and proceed to inject the ink.
8. The unit is now ready to use.
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
5
4.0 SUMMARY OF THEORY
The theory is named in honor of Osborne Reynold’s, a British engineer who discovers the variables that can be used as a criterion to distinguish between laminar and turbulent flow. The Reynolds number is widely used dimensionless parameters in fluid mechanics.
Reynolds number formula: V
ULR =
R = Reynolds number U = Fluid velocity, (m/s) L = characteristic length or diameter (m) V = Kinematic viscosity (m2/s) Reynolds number R is independent of pressure
4.1 Pipe Flow Conditions
For water flowing in pipe or circular conduits, L is the diameter of the pipe. For Reynolds number less than 2100, the pipe flow will be laminar. For Reynolds number from 2100 to 4000 the pipe flow will be considered a transitional flow. Turbulent occur when Reynolds number is above 4000. The viscosity of the fluid also determines the characteristic of the flow becoming laminar or turbulent. Fluid with higher viscosity is easier to achieve a turbulent flow condition. The viscosity of fluid is also dependant on the temperature.
4.2 Laminar Flow
Laminar flow denoted a steady flow condition where all streamlines follow parallel paths, there being no interaction (mixing) between shear planes. Under this condition the dye observed will remain as a solid, straight and easily identifiable component of flow.
4.3 Transitional Flow
Transitional flow is a mixture of laminar and turbulent flow with turbulence in the center of the pipe, and laminar flow near the edges. Each of these flows behaves in different manners in terms of their frictional energy loss while flowing, and have different equations that predict their behavior.
4.4 Turbulent Flow
Turbulent flow denotes an unsteady flow condition where streamlines interact causing shear plane collapse and mixing of the fluid. In this condition the dye observed will become disperse in the water and mix with the water. The observed dye will not be identifiable at this point.
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
6
5.0 EXPERIMENT PROCEDURES
5.1 Experiment A
Experiment objectives:
− To compute Reynold’s number (R).
− To observe the laminar, transitional and turbulent flow.
1. Lower the dye injector until it is seen in the glass tube. 2. Open the inlet valve, V1 and allow water to enter stilling tank. 3. Ensure a small overflow spillage through the over flow tube to maintain a
constant level. 4. Allow water to settle for a few minutes. 5. Open the flow control valve fractionally to let water flow through the
visualizing tube. 6. Slowly adjust the dye control needle valve until a slow flow with dye
injection is achieved. 7. Regulate the water inlet valve, V1 and outlet valve, V2 until a straight
identifiable dye line is achieved. The flow will be laminar. 8. Measure the flow rate using volumetric method. 9. Repeat the experiment by regulating water inlet valve, V1 and outlet valve,
V2 to produce transitional and turbulent flow.
5.2 Experiment B
Experiment objectives:
− To determine the Reynold’s number (R)
− To determine the upper and lower critical velocities at transitional flow.
1. Lower the dye injector until it is seen in the glass tube. 2. Open the inlet valve, V1 and allow water to enter stilling tank. 3. Ensure a small overflow spillage through the over flow tube to maintain a
constant level. 4. Allow water to settle for a few minutes. 5. Open the flow control valve fractionally to let water flow through the
visualizing tube. 6. Slowly adjust the dye control needle valve until a slow flow with dye
injection is achieved. 7. By repeating the procedures to create a laminar flow, slowly increase the
flow rate until the laminar flow produce small disturbance or eddies. This will be lower critical velocity.
8. Determine the flow rate by using a volumetric result. 9. Repeat the experiment by first introducing a turbulent flow and slowly
decrease flow rate till the flow become transitional. This will be upper critical velocity
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
7
5.3 Data sheet
Reynolds number Re (non-dimensional) Friction Factor λ (non-dimensional) Kinematics viscosity v mm2/sec Pipe diameter D mm Mean velocity U mm/sec Higher Critical velocity Ucrit mm/sec Lower Critical velocity Ucrit mm/sec Flow rate Q L/s
Volume (L) Time (s) Flow rate, Q (L/s)
Flow rate, Q (m3/s)
Reynold’s Number
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
8
APPENDIX A
Typical Experimental Result
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
9
A.1 Experiment 1 Laminar Flow
Transitional Flow
Volume (L)
Time (S)
Flow rate, Q (L/s)
Flow rate, Q (m3/s)
Reynold’s Number
0.15 6.0 0.0250 2.50000E-05 2294.2526
Turbulent Flow
Volume (L)
Time (S)
Flow rate, Q (L/s)
Flow rate, Q (m3/s)
Reynold’s Number
0.15 2.5 0.0600 6.00000E-05 5506.2062
A.2 Experiment 2 Lower Critical Flow (from laminar changing to transitional flow)
Volume (L)
Time (S)
Flow rate, Q (L/s)
Flow rate, Q (m3/s)
Reynold’s Number
0.15 6.5 0.02308 2.31E-05 2117.772
Upper Critical Flow (Changing from turbulent flow to transitional flow)
Volume (L)
Time (S)
Flow rate, Q (L/s)
Flow rate, Q (m3/s)
Reynold’s Number
0.15 3.5 0.04286 4.29E-05 3933.004
Volume (L)
Time (S)
Flow rate, Q (L/s)
Flow rate, Q (m3/s)
Reynold’s Number
0.25 60.0 0.0042 4.16667E-06 382.3754
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
10
If Re < 2100 is laminar flow If 2100 < Re < 4000 is transitional flow If Re > 4000 is turbulent flow Kinematics viscosity for 25°C water = 0.89 x 10-6 m/s
=Re
Thus V
DU ×=Re
A
QU = Glass tube diameter (D) = 0.0156 m, Area (A) = 1.91x10-4 m2
Thus, VA
DQ
×
×=Re
For laminar flow, 0689.00491.1
0156.00616667.4Re
−×−
×−=
EE
E
= 382.3754
Mean velocity, U × Glass tube diameter, D
Kinematic viscosity, V
SOLTEQ® OSBORNE REYNOLD’S DEMONSTRATION (MODEL: FM 11)
11
Typical visual test result
Laminar flow Transitional flow
Turbulent flow