Cavitating Herschel Venturi nozzle test rig
Heiko Warnecke, Dep. 1.53 Liquid Flow
� Flow rate control device� Proportioning of liquids� Flow meter
introduction | characterisation | different liquids | load profiles | conclusion 2 Heiko Warnecke
introduction
� Reproducibility� Flow rate stability� Fast reaction time� Small � Cheap� …
introduction
introduction | characterisation | different liquids | load profiles | conclusion 3 Heiko Warnecke
� Influence of numerous factors on thecavitation
• Flow cross-section
• Liquid
• Reynolds-number
• Upstream and downstreampressure cylindric?
diameter
surface roughness
axial?
Nozzle throat
d
1,9 x d
edge3,3 x d
10 x d
set-up
introduction | characterisation | different liquids | load profiles | conclusion 4 Heiko Warnecke
� 6 nozzles with a nominal diameter of0.74 mm, 1.4 mm and 2.6 mm arecharacterised
� flow rates between 37 l/h and 588 l/h
characterisation
introduction | characterisation | different liquids | load profiles | conclusion 5 Heiko Warnecke
Nozzle nr. i
DiameterD
mm± 1 µm
Flow Q (4 bar)
l/h± 0.1 %
Slopeb
l/h/bar
1 0.740 42.69 5.4 ± 0.2
2 0.738 42.65 5.4 ± 0.2
3 1.396 151.80 19.2 ± 0.4
4 1.397 152.40 19.5 ± 0.5
5 1.393 154.50 19.5 ± 0.5
6 2.601 527.80 71.0 ± 1.4
characterisation
introduction | characterisation | different liquids | load profiles | conclusion 6 Heiko Warnecke
3 4 5
40
60
80
100
120
140
160
180
nozzle 1 nozzle 2 nozzle 3 nozzle 4 nozzle 5
flow
/ l/h
upstream pressure / bar
2 3 4 5300
400
500
600
flow
/ l/h
upstream pressure / bar
nozzle 6 linear regression
equation y = a + b*x
a 238.45
b 71.02
r² 0.99776� Assumption of a linear
correlation between flow rate and upstream pressure
Nozzle nr. i
DiameterD
mm± 1 µm
Flow Q (4 bar)
l/h± 0.1 %
Slopeb
l/h/bar
1 0.740 42.69 5.4 ± 0.2
2 0.738 42.65 5.4 ± 0.2
3 1.396 151.80 19.2 ± 0.4
4 1.397 152.40 19.5 ± 0.5
5 1.393 154.50 19.5 ± 0.5
6 2.601 527.80 71.0 ± 1.4
characterisation
introduction | characterisation | different liquids | load profiles | conclusion 7 Heiko Warnecke
� Different nozzles with same nominal diameter
� Significant difference of theflow rates
additivity
introduction | characterisation | different liquids | load profiles | conclusion 8 Heiko Warnecke
0 200 400 600 800 1000 1200
-0.20
-0.15
-0.10
-0.05
0.00
0.05
0.10
0.15
rel.
dev.
/ %
flow / l/h
���� =�����
+ � − � ∗ ��) Qi: single nozzle flow rate
bi: calculated slope of each nozzle
pi: upstream pressure of single nozzle flow
pj: upstream pressure of multiple nozzle flow���. ���. = ���� −��������
different liquids
introduction | characterisation | different liquids | load profiles | conclusion 9 Heiko Warnecke
Medium Principalconstituents
Density
g/cm3
Vapourpressurembar
Viscosity
mm2/sWhite spirit Hydrocarbon,
C10 – C13,n-Alkane,iso-Alkane,cycliccompound
0.785 0.5 1.2
Haku 1025-310
Hydrocarbon,C11 – C14,iso-Alkane,cycliccompound
0.761 0.6 1.3
Water Tap water 0.998 23.4 1.0
physical properties density, vapour pressure and kinematic viscosity at 20°C
different liquids
introduction | characterisation | different liquids | load profiles | conclusion 10 Heiko Warnecke
⇒Similar flow rates of white spirit and cleaner solvent⇒The flow rate of water is higher at the same
upstream pressure⇒Comparable standard deviation for different liquids
different liquids
introduction | characterisation | different liquids | load profiles | conclusion 11 Heiko Warnecke
3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
30
33
36
39
42
45
48
51
mas
s flo
w /
kg/h
upstream pressure / bar
water white spirit 180/210 Haku 1025-310
d = 0.74 mmd = 1.4 mm
Medium Standard deviation
White spirit 0.097 %
Haku 0.018 %Water 0.023 %
load profiles
introduction | characterisation | different liquids | load profiles | conclusion 12 Heiko Warnecke
Load profiles of a typical german household are generated
⇒How can a load profile be realised in a test rig?
load profile
introduction | characterisation | different liquids | load profiles | conclusion 13 Heiko Warnecke
Apartment house
Example
[Schumann et al. 2017]
New characterisation for water meters close to real world conditions
load profile
introduction | characterisation | different liquids | load profiles | conclusion 14 Heiko Warnecke
� Flow rates at constant upstream pressure� pressure ratio smaller than 0.6
load profile section
introduction | characterisation | different liquids | load profiles | conclusion 15 Heiko Warnecke
⇒pressure excursions of 7% for about 1 s⇒No effect seen on the balance signal
� Flow rates of the individual nozzles sum up to theexpected flow rates
� A constant mass flow can be generated withdifferent liquids, including liquid mixtures
� With the nozzles a load profiles can be generatedwith fast flow rate changes
conclusion
introduction | characterisation | different liquids | load profiles | conclusion 16 Heiko Warnecke
� Characterisation and verification of liquid properties (vapour pressure, viscosity, etc)
� Characterisation of nozzle properties(surface roughness, edges, etc)
� Variation of measurement conditions(pressure, temperature, etc)
outlook
introduction | characterisation | different liquids | load profiles | conclusion 17 Heiko Warnecke
Physikalisch-Technische BundesanstaltBraunschweig and BerlinBundesallee 10038116 Braunschweig
Heiko WarneckeTelefon:0531 592-1389E-Mail: [email protected]
Stand: 06/2019
⇒Different flow rates of water and the two other liquids at the same pressure
introduction | characterisation | different liquids | load profiles | conclusion 20 Heiko Warnecke
• Nominal diameter 1.4 mm (left) for water and cleaner solvent and 2.6 mm (right) for water and white spirit
3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0440
480
520
560
600
640
mas
s flo
w /
kg/h
upstream pressure / bar
water white spirit
Different liquids