HM150.35 Horizontal Osborne Reynolds Demonstrator

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Instructions Manual
HM150.35 Horizontal Osborne
Reynolds Demonstrator
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
04/01
HM150.35 Osborne Reynolds Apparatus
Instruction Manual
Printed document No.: 917.00035A15012
04/01
HM150.35 Osborne Reynolds Apparatus
Table of Contents
Unit Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1
2
Preparation and Setting Up the Unit . . . . . . . . . . . . . . . . . . . 2
3
Performing the Experiment. . . . . . . . . . . . . . . . . . . . . . . . . . . 3
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
04/01
1
3.1
4
Experiments . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Technical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 6
HM150.35 Osborne Reynolds Apparatus
1
Unit Description
The unit is intended for the investigation and demonstration of the Osborne Reynolds experiments.
The experimental setup facilitates the demonstration of laminar and turbulent flow. The flow
is made visible with an ink trace in a transparent
section of tube.
04/01
4
2
3
5
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
9
11
8
6
7
10
1
The unit essentially comprises:
-
Base plate [1].
-
Water supply tank [2] with height adjustment
[9] and connection for water supply [11].
-
Overflow section [3] for the generation of a
constant pressure head in the supply tank.
-
Aluminium tank [4] for ink with metering cock
[5] and brass injection nozzle [6].
-
Experiment tube [8] made of Plexiglass with
streamlined inlet section [7].
-
Drain cock [10] for adjusting the flow rate in
the experiment tube.
To visualise the flow we recommend blue ink,
which is carefully introduced into the flowing water
1 Unit Description
1
HM150.35 Osborne Reynolds Apparatus
via the aluminium tank with injection nozzle. The
water supply can be realised using the HM150
Basic Hydraulics Bench. The flow rate measurement is made using a measuring tank or using the
HM150.
Preparation and Setting Up the Unit
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
04/01
2
The following must be performed to set up and
prepare for the experiment:
12
11
-
Place the unit on a bench or on the HM150. If
you are not using the HM150, a permanent
water drain should be available near the unit.
-
Connect the water drain hose to the drain cock
[10] or place the unit over a drain. If you are
using the HM150, you can set up the unit such
that the water is drained directly into the reservoir in the HM150.
Water with ink should not be allowed to drain
into the HM150 reservoir.
-
Connect the outlet [12] on the supply tank to
the inlet [13] on the test section by means of
a hose.
-
Connect a water supply to the inlet [11] on
the supply tank using a hose.
-
Fill the aluminium tank [4] with ink. The ball
cock [5] underneath the tank must be closed.
13
10
4
5
2 Preparation and Setting Up the Unit
2
HM150.35 Osborne Reynolds Apparatus
3
Performing the Experiment
8
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
04/01
12
-
Close the drain cock [12].
-
Switch on the water supply.
On the HM150, the pump. Carefully open the
ball cock above the pump or the water cock on
the laboratory supply.
-
Adjust the cock such that a constant water level
is established in the supply tank.
-
After a certain amount of time, the experiment
tube [8] fills.
-
The remaining air can be removed from the
experiment tube by undoing the bleed screw
[14].
14
The experiment can now begin.
Open the drain cock a little such that a low flow rate
is produced in the experiment tube. It is best to
dispose of the dyed water down a drain.
3 Performing the Experiment
3
HM150.35 Osborne Reynolds Apparatus
3.1
Experiments
The objective of this experimental setup is the
demonstration of laminar and turbulent flow.
At a low flow rate laminar flow is established.
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
04/01
For this purpose open the drain cock a little.
5
Blue ink is used to visualise the flow. A fine blue
flow line can be generated using the metering cock
[5], which shows the laminar flow.
At a high flow rate turbulent flow occurs
For this purpose open the drain cock further.
The flow line is broken up by the turbulent flow.
Flow Path
The change from laminar flow to turbulent flow
occurs at:
Recr ≈ 2300
Relam. ≤ 2300 signifies laminar flow
Retur. ≥ 2300 signifies turbulent flow
The Reynolds number is calculated from
Re =
w⋅d
ν
with
d= Inside diameter of the pipe section [m]
w= Flow speed [m/s]
ν= Viscosity of the medium [m2/s],
water: ν = 1 ⋅ 10 −6 [m2/s]
The flow speed can be determined from the volumetric flow rate; this is determined using a measuring tank and a stopwatch.
3 Performing the Experiment
4
HM150.35 Osborne Reynolds Apparatus
.
V
w=
A
with
A=
π ⋅ d2
4
Pipe diameter d = 16mm = 0.016m
.
V= Volumetric flow rate
04/01
A= Cross-sectional area of the pipe
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
The figure below shows the three
flow conditions:
Relam. ≤ 2300
3 Performing the Experiment
-
Laminar flow
-
Transition laminar / turbulent flow
-
Turbulent flow
Recr ≈ 2300
Retur. ≥ 2300
5
HM150.35 Osborne Reynolds Apparatus
4
Technical Data
Supply Tank:
Experiment Tube:
Inside Diameter:
Length:
2.0
litres
16
700
mm
mm
Ink Tank:
270
ml
1070 x 640 x 720
25
mm
kg
All rights reserved G.U.N.T. Gerätebau GmbH, Barsbüttel
04/01
Overall Dim.:
Weight:
4 Technical Data
6
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