Atomization Characteristics of High-Flow Variable-Orifice Flooding
Nozzles
Alvin R. Womac
Abstract
Droplet spectra factors for variable-orifice flooding nozzles in quasi-static air were
investigated to possibly aid the reduction of spray drift, and to provide a basis for future
atomizer design. A laser-diffraction instrument measured the droplet size spectra of
water sprays through orifices with diameters ranging from 1.14 to 6.35 mm. Spray
discharge flow rates up to 40 L min-1 were measured with a Coriolis-type sensor.
Nozzles produced an array of droplet size spectra with volume median diameters (D v0.5)
ranging from 296 to 1062 µm. For single-orifice flooding nozzles, orifice diameter was
the most important factor positively correlated with droplet size spectra factors, except
the Dv0.9 . For flooding nozzles utilizing two orifices in series, the magnitude of difference
between the two orifice diameters was the most important factor positively correlated
with droplet size spectra factors. Also, two-orifice flooding nozzles had strong negative
correlations between pressure and droplet size factors. Whereas, single-orifice flooding
nozzles had strong positive correlations between flow rate and droplet size factors. A
unique flow–pressure phenomenon, in which flow decreased or remained steady with
increasing pressure, was observed for some orifices and pressures - possibly due to
orifice inlet limiting conditions. The use of regression coefficients predicted most droplet
size spectra factors with coefficients of determination (r2) ranging from 0.72 to 0.91,
except for low r2 values (0.11 to 0.50) associated with the Dv0.9 of single orifice nozzles.
Keywords. Applicators, Atomizers, Drift, Droplets, Quality control, Spray, Sprayers
<< Footnotes are on page 15 >>
2
Introduction
Spray drift reduction is very important since pesticides have been detected in the
atmosphere across the nation (Majewski and Capel, 1995) and in Canadian arctic snow
(Gregor, 1990). The use of increased droplet size spectra on boom-type sprayers may
reduce drift under various conditions due to increased spray plume porosity to airflow
(Murphy et al., 2000) and increased droplet sedimentation (Zhu, 1994).
Flooding nozzles typically produce very coarse and extremely coarse (ASAE
S572, 2000) droplets. As a result, sprayers may be reasonably engineered for reduced
spray drift using flooding nozzles. The nozzle design is simple, since a round liquid jet is
directed onto a curved surface to form a fan spray (Lefebvre, 1989). Also, the use of a
secondary orifice in series downstream from the primary metering orifice may reduce
the production of small drift-prone droplets (Pearson et al., 1993).
Flooding nozzles with nominal flow ratings of 1.5 L min-1 and less for boom
sprayers were droplet-size tested (Womac et al., 1997). New variable-orifice flooding
nozzles have become commercially available in nominal flow ratings up to 23 L min -1.
Variable orifice selections may affect the droplet spectra, though there is little data
published for these nozzles for ground boom applications in quasi-static air. Also, the
availability of regression coefficients for droplet spectra factors from variable-orifice
flooding nozzles in quasi-static air would aid future design.
3
The objectives of the study were:

to determine the influence of variable-orifice flooding nozzle type, orifice size,
operating pressure, and nozzle flow rate on emitted droplet spectra;

to determine regression coefficients to predict droplet spectra from variableorifice flooding nozzles.
Materials and Methods
Nozzles and Pressures
A manufacturer (CP Products Co., Inc.) supplied representative samples of four
types of variable-orifice flooding nozzles. Nominal flow ratings ranged up to 23 L min -1.
The nozzles produced flat sprays with long-axis discharge angles ranging up to 150˚.
All tested nozzles had variable orifices selected by indexing a round, flat orifice plate so
that the selected orifice was in alignment with a pressurized supply chamber. Orifice
centers, as measured radially from the center of the orifice plate, increased with
increasing orifice size to maintain a tangent of the orifice circumference in alignment
with the radial-innermost dimension of a deflector.
Single orifice nozzles (Figure 1) were distinguished from nozzles that used two
orifices in series (Figure 2). Each type of nozzle had a different type of deflector, or had
selectable flood-type tips that served as a secondary orifice and a deflector. The CP
Floater Turbo nozzle and CP Sprayer Turbo nozzle utilized the flood-type tips. A
common aspect of all spray deflectors was that they terminated with a trailing edge at
90˚ from the discharge orifice. Descriptions of nozzles and orifice size ranges are as
follows:
4
The CP 360˚ nozzle (Figure 3) had stainless steel variable orifices ranging in
diameter from 1.32 to 6.35 mm, and the orifice selection resulted in a single-orifice
operation (Figure 1). A stainless steel 360˚ deflector encircled the orifices. Discharge
distance, defined as the width of the opening between the orifice plate and trailing edge
of the deflector measured normal to the orifice plate, was approximately 12 mm. The CP
360˚ nozzles were droplet size tested at pressures of 138, 207, 276, and 345 kPa.
The CP 3-way nozzle (Figure 4) had stainless steel variable orifices ranging in
diameter from 1.32 to 6.35 mm, and the orifice selection resulted in a single-orifice
operation (Figure 1). Three stainless steel deflector settings were available. Discharge
distances, as defined above, for small (S), medium (M), and large (L) deflectors were
about 6, 10, and 14 mm. Manufacturer-recommended combinations of orifice size and
deflector selection were tested – such that increasing orifice sizes used increasing
deflector sizes. The CP 3-way nozzles were droplet size tested at pressures of 138,
207, 276, and 345 kPa.
The CP Floater Turbo nozzle (Figure 5) had plastic orifices ranging in diameter
from 1.32 to 6.35 mm, and stainless steel flood tips (secondary orifices) ranging in
diameter from 1.85 to 6.35 mm. Selection of orifice and flood tip resulted in two orifices
in series (Figure 2). The CP Floater Turbo nozzles were droplet size tested at pressures
of 138, 207, 276, 345, and 414 kPa.
The CP Sprayer Turbo nozzle (Figure 6) had plastic orifices ranging in diameter
from 1.14 to 4.39 mm, and stainless steel flood tips (secondary orifices) ranging in
diameter from 1.85 to 4.39 mm. Selection of orifice and flood tip resulted in two orifices
5
in series (Figure 2). The CP Sprayer Turbo nozzles were droplet size tested at
pressures of 69, 138, 207, and 276 kPa.
Droplet Sizing Laser Instrument
A Malvern 2605 Lc droplet/particle size analyzer (Malvern Instruments, Malvern,
England) monitored the number density weighted droplet spectra. Spray droplets were
discharged down through a collimated laser beam to diffract light onto a multi-element
detector. The instrument uses the detected energy signature for mathematical inversion
and determines the droplet spectra. According to the manufacturer, the instrument has
an overall accuracy of ±4%.
A variable-orientation test stand supported the laser instrument so that the spray
plume from a nozzle was traversed across the laser beam approximately 20 times per
measurement run, with the long axis of spray at a right angle to the laser beam. The
nozzle output was approximately 250 mm above the laser. This height was determined
based on avoidance of the sheet action of spray at the nozzle, spatial density of
droplets, and minimization of the traverse distance. Instrument lens selection was
generally 800 mm, although a few runs with a 1000 mm lens were conducted. Lens
selection had little effect on the measurements for the tested nozzles. Fiberglass filter
media on the instrument bed reduced droplet rebound thereby minimizing measurement
bias. A minimum of three replicate measurement runs was conducted. Tap water was
the test liquid. Droplet size measures were conducted as described by Womac et al.
(1999) and Womac (2000).
Pressures were measured using a 0.25%-accuracy precision test gage mounted
close to the nozzle via a tee plumbed in the supply line. Flow rates through nozzles
6
were monitored with a Coriolis-type mass flow meter (Model CMF050, Micro Motion,
Inc., Boulder, CO). The manufacturer designed and certified (N.I.S.T. traceable) the flow
meter for flows ranging from 0.19 to 76 L min-1 with accuracies from ±1.54 to ±0.10 %,
respectively.
Data Analyses
Dv0.1, Dv0.5, and Dv0.9 are droplet size spectra factors corresponding with 10, 50,
and 90%, respectively, of the cumulative spray liquid volume contained in droplets up to
the indicated diameter (ASAE S327.2, 1997). These factors were calculated by the laser
instrument software and were used exclusively throughout this study to indicate the
droplet spectra.
An analysis of variance (SAS, Cary, NC) of pooled data was conducted. Droplet
size spectra factors were dependant variables. Independent variables included nozzle
type, orifice size, secondary orifice size (used on CP Floater Turbo and CP Sprayer
Turbo nozzles), difference in orifice and secondary orifice sizes (delta orifice), and
pressure. For clarification, % delta orifice, a variant of delta orifice, is the percentage
increase in the secondary orifice diameter over the orifice diameter. All variables were
highly significant in the analysis of variance. The analysis of variance aided the
selection of factors for the regression analyses.
Data were sorted by nozzle type for additional analyses. A correlation analysis
provided Pearson correlation coefficients (Ray, 1982a) that may be useful for future
nozzle design by determining the relative importance of flood nozzle type, orifice size,
and pressure on droplet spectra. Droplet spectra factors were correlated with orifice
size, secondary orifice size, delta orifice, pressure, and flow rate. In addition,
multivariate, polynomial regression analyses (Ray, 1982b) were conducted for each
7
nozzle type. Droplet size spectra factors were predicted based on intercept, orifice size,
(orifice size)2, secondary orifice size, (secondary orifice size)2, pressure, and
(pressure)2. Coefficients for the model variables are presented. This model was
selected based on trial and error to maximize the coefficient of determination (r 2).
Results
Droplet size
The complexity of atomization trends between droplet size factors and nozzle
factors warranted the tabulation of droplet size factors for each nozzle (Tables 1, 2, 3,
and 4). Also, an unexpected complexity in flow rate decreasing, or only slightly
increasing, with pressure increases to 345 kPa for 6.35 mm orifices of the CP 360º and
CP 3-way nozzles also merited specific data. The Dv0.5 ranged from 296 (Table 3) to
1062 µm (Table 4) when all nozzles and nozzle factors were considered.
Table 1 shows the mean droplet size spectra factors for the CP 360º nozzle.
Dv0.1, Dv0.5, and Dv0.9 generally increased at each tested pressure as the orifice diameter
increased from 1.32 to 2.64 mm. Up to an orifice diameter of 2.64 mm, most factors
decreased as pressure increased. The Dv0.9 for the 2.64 mm orifice tended to increase
with increased pressure and were the maximum Dv0.9 values considering all orifices of
this nozzle. Orifice diameters of 3.28 mm and up exhibited a trend in mean droplet
spectra factors that differed from smaller orifices. Dv0.1 and Dv0.5 values tended to peak
for this nozzle with the 3.28 mm orifice. Nozzle pressure had less of an effect on the
droplet size spectra for orifice sizes ranging from 3.76 to 6.35 mm. For example, the CP
360º nozzle with orifice diameters of 4.57 and 6.04 mm had similar Dv0.5 values of about
8
500 µm as pressure increased from 138 to 345 kPa. However, the 4.09 and 5.31 mm
orifices demonstrated slight decreases in Dv0.5 as pressure increased.
Table 2 lists the mean droplet size spectra factors for the CP 3-way nozzle. The
overall trend was for Dv0.1 to increase with increasing nozzle size, though the increase
was irregular. Dv0.5 and Dv0.9 also tended to irregularly increase with increasing nozzle
size. Specific exceptions to these increases were noted. The Dv0.5 decreased 93 µm as
orifice size increased from 2.64 to 3.28 mm at 345 kPa. Similarly, Dv0.5 decreased 42
µm as orifice size increased from 4.09 to 4.57 mm at 345 kPa. Droplet size factors
generally decreased as pressure increased. However, lowest values in Dv0.5 often
occurred at neither the highest nor lowest pressures, such as 207 and 276 kPa as in the
case of 2.31 and 2.64 mm orifices. Dv0.5 was often nearly constant or only slightly
decreased with pressure for orifice sizes from 3.28 to 4.57 mm. Increasing the orifice
size from 3.28 to 4.57 mm had little effect or slightly increased the Dv0.5 when averaged
across pressure. Also, increasing the size of the deflector tended to slightly increase the
droplet size spectra factors for the 2.64, 3.76, and 4.57 mm orifices, though the 3.76
mm orifice at 207 and 276 kPa was an exception. Perhaps the reduced sharpness of
the curved path length of larger deflectors did not breakup, or shear, the jet of liquid as
much as small deflectors.
Table 3 presents the mean droplet size spectra factors for the CP Floater Turbo
nozzle. The delta orifice effect was noted with small orifices. The 1.32 mm orifice and
2.31 mm secondary orifice (delta orifice = 0.99 mm, or 75 % delta orifice) produced a
Dv0.5 of 1019 µm at 138 kPa while the 1.85 mm orifice and 1.85 mm secondary orifice
(delta orifice = 0 mm, or 0 % delta orifice) had a Dv0.5 of 462 µm at 138 kPa (Table 3).
9
The delta orifice effect was also noted as orifice diameter increased. The 3.28 mm
orifice produced mean Dv0.5 values of 642, 653, 874, and 882 µm when in combination
with secondary orifices with diameters of 3.28, 3.58, 4.57, and 4.98 mm, respectively, at
a pressure of 138 kPa (Table 3). Delta orifice values (and % delta orifice) were 0 (0%),
0.3 mm (9 %), 1.29 mm (39 %), and 1.7 mm (52 %) for these 3.28, 3.58, 4.57, and 4.98
mm secondary orifices. A large increase in Dv0.5 was observed as the % delta orifice
increased from 9 to 39 %. Also, other droplet size factors increased as % delta orifice
increased. The Dv0.1 for the previous example increased from 247 to 421 µm as the %
delta orifice increased from 9 to 39 %.
Table 4 lists the mean droplet size spectra factors for the CP Sprayer Turbo
nozzle. This nozzle produced some of the largest droplet sizes measured in this study,
and may be attributed to the lowest test pressure of 69 kPa. The largest droplet size
factors of the study were produced by the 1.14 mm orifice and 1.85 mm secondary
orifice at 69 kPa. This combination produced mean Dv0.1, Dv0.5, and Dv0.9 values of 518,
1062, and 1408 µm, respectively (Table 4). Delta orifice (% delta orifice) was 0.71 mm
(62 %) for this combination of orifice diameters. The delta orifice effect was similar to
that of the previous nozzle. For example, the 1.85 mm diameter orifice and secondary
orifice (0 % delta orifice) produced much smaller droplets (Dv0.1=228 µm, Dv0.5=652 µm,
Dv0.9=1239 µm) at 69 kPa than the previously discussed combination with a 1.85 mm
secondary orifice.
10
Flow rates
Overall, flow rates increased as orifice diameter increased and as pressure
increased. However, the 6.35-mm orifice of the CP 360 nozzle had a decrease in flow
rate from 39.15 to 38.23 L min-1 as pressure increased from 276 to 345 kPa. Shock and
turbulence in the discharge pattern noticeably increased with a pressure increase to 345
kPa, and the nozzle produced hissing sounds resembling air induction, though air leakin points were not identified. Since the orifice plate was approximately 6.35 mm thick, it
was hypothesized that the orifice was behaving as pipe flow operating under inlet
limiting conditions. This may be possible due to streamlines from the large supply port
being transitioned into the small orifice such that a necking, or constriction, occurred
inside the orifice. As a result, full pipe flow through the orifice may not have been
realized. Negative pressures at a constriction may have pulled the fluid apart as a vapor
that caused the characteristic hissing sounds upon flow discharge. Subsequent
smoothing and machining of the inlet side of the orifice altered the flow characteristics
and may bear out this hypothesis. All droplet size and flow data reported pertain to the
original orifice.
Correlation coefficients
Pearson correlation coefficients for each nozzle (Tables 5, 6, 7 and 8) indicated
various droplet size correlations with orifice and pressure. These coefficients may be
useful for future nozzle design by determining the relative importance of nozzle style,
orifice size, and pressure on droplet spectra. Generally, the CP 360º and CP 3-way
nozzles exhibited a strong positive correlation (0.568 to 0.849) between droplet spectra
11
factor with orifice diameter (Tables 5, 6). An exception (-0.008) occurred for the Dv0.9 for
the CP 360º nozzle. Weak droplet spectra factor correlations (0.057 to –0.215) occurred
with orifice diameter for the CP Floater Turbo and CP Sprayer Turbo nozzles (Tables 7,
8). Droplet spectra factors for these nozzles were strongly correlated (0.573 to 0.712)
with delta orifice. Droplet spectra factors for each nozzle were negatively correlated with
pressure (Tables 5, 6, 7, 8). Correlations with pressure were generally weaker than
correlations with orifice diameter (or delta orifice), except for the pressure correlations of
the CP Sprayer Turbo nozzle (-0.533 to –0.594) (Table 8). Flow rate and orifice
diameter were similarly correlated with droplet spectra factors. This trend was expected
since flow rate is largely determined by orifice size. These correlations may be useful in
identifying the most important parameters for future nozzle design.
Regression coefficients
Regression modeling of droplet size factors by nozzle type determined
coefficients of determination (r2) ranging from 0.11 to 0.91 (Tables 9, 10, 11, 12). Nozzle
types without secondary orifices (CP 360º and CP 3-way nozzles) tended to have
decreasing r2 with increasing droplet size factor, whereas r2 values were somewhat
uniform for the CP Floater Turbo and CP Sprayer Turbo nozzles. The least r 2 (0.11) was
for the Dv0.9 of the CP 360º nozzle (Table 9), and coincides with a lack of correlation
between Dv0.9 and orifice diameter (Table 5). Prediction of Dv0.9 for the other single
orifice nozzle, the CP 3-way nozzle, resulted in an r2 of 0.50. All other r2 values were
0.72 and greater.
12
Regression coefficients, P levels, and standard error of estimates are tabulated
in Tables 9, 10, 11, and 12. It should be noted that the prediction accuracy varies with
the selection of parameter values. The CP Floater nozzle with 2.31 mm orifice and 3.58
mm orifice at 138 kPa had a Dv0.5 predicted at 881 µm versus a measured value of 882
µm (Table 3). On the other hand, this same combination at 414 kPa had a predicted
Dv0.5 of 726 µm versus a measured value of 685 µm (Table 3). Finally, regression
coefficients may be of interest for inclusion in atomization models used for spray drift
prediction.
Conclusions
The following conclusions were determined for tests conducted on variableorifice flooding nozzles in quasi-static air:

The rank order of the four tested nozzles, in terms of potential drift reduction
based on Dv0.5 is as follows: CP 360 nozzle (463 µm), CP 3-way nozzle (467
µm), CP Floater Turbo nozzle (640 µm), and CP Sprayer Turbo nozzle (715 µm).

The rank order of the four tested nozzles, in terms of potential drift reduction
based on Dv0.1 is as follows: CP 3-way nozzle (147 µm), CP 360 nozzle (151
µm), CP Floater Turbo nozzle (247 µm), and CP Sprayer Turbo nozzle (276 µm).

Generally, orifice size is the single most important factor positively correlated with
droplet size factors – for single orifice flooding nozzles. However, exceptions for
correlations with Dv0.9 can occur.

For flooding nozzles utilizing two orifices in series, the difference in orifice
diameters (delta orifice) is the single most important factor positively correlated
with droplet size factors.
13

Pressure is negatively correlated with droplet size factors on flooding nozzles.
Two-orifice flooding nozzles have stronger correlations between pressure and
droplet size factors than single orifice flooding nozzles.

Generally, flow rate has a strong positive correlation with droplet size factors for
single orifice flooding nozzles. Exceptions for this correlation with Dv0.9 can
occur.

On the other hand, two-orifice flooding nozzles produce slight negative
correlations between flow rate and droplet size factors.

Unique flow – pressure phenomena can occur with single-orifice flooding
nozzles. Increasing pressure can result in decreased or steady flow rates.

Generally, regression coefficients involving orifice diameter, secondary orifice
diameter, and pressure may provide an acceptable prediction of droplet spectra
factors for variable-orifice flooding nozzles in quasi-static air. However, accurate
prediction of Dv0.9 for single orifice nozzles can be poor.
14
References
ASAE S327.2 1997. Terminology and definitions for agricultural chemical application.
ASAE S327.2 Dec95, ASAE Standards-44th Edition, ASAE.
ASAE S572. 2000. Spray nozzle classification by droplet spectra. ASAE S572 Aug99,
ASAE Standards – 47th Edition, ASAE.
Gregor, D.J. 1990. Deposition and accumulation of selected agricultural pesticides in
Canadian artic snow. in Kurtz, D.A., ed., Long Range Transport of Pesticides, Lewis
Publishers, Inc., Chelsea, Michigan.
Lefebvre, A.H. 1989. Atomization and Sprays. Hemisphere Publishing Corp., New York.
Majewski, M.S. and P.D. Capel. 1995. Pesticides in the Atmosphere – Distribution,
Trends, and Governing Factors. Ann Arbor Press, Inc., Chelsea, Michigan.
Murphy, S.D., P.C.H. Miller, and C.S. Parkin. 2000. The effect of boom section and
nozzle configuration on the risk of spray drift. Journal of Agricultural Engineering
Research 75(2): 127-137.
Pearson, S.L., T. Reed, and B. Göbel. 1993. New developments in spray tips to reduce
drift. Paper No. 93-1081. ASAE.
15
Ray, A.A. 1982a. SAS User’s Guide: Basics, 1982 Edition. Ed. A.A. Ray, SAS Institute,
Inc., Cary, North Carolina.
Ray, A.A. 1982b. SAS User’s Guide: Statistics, 1982 Edition. Ed. A.A. Ray, SAS
Institute, Inc., Cary, North Carolina.
Womac, A.R., J.C. Goodwin, and W.E. Hart. 1997. Tip selection for precision
application of herbicides. Bulletin 695, The University of Tennessee Agricultural
Experiment Station, Knoxville, Tennessee.
Womac, A.R., R.A. Maynard, II, and I.W. Kirk. 1999. Measurement variations in
reference sprays for nozzle classification. Transactions of the ASAE 42(3):609-616.
Womac, A.R. 2000. Quality control of standardized reference spray nozzles.
Transactions of the ASAE 43(1):47-56.
Zhu, H., D.L. Reichard, R.D. Fox, R.D. Brazee, H.E. Ozkan. 1994. Simulation of drift of
discrete sizes of water droplets from field sprayers. Transactions of the ASAE
37(5):1401-1407.
16
Footnotes:
Article was submitted for publication in _______; reviewed and approved for publication
by the Power and Machinery Division of ASAE in ________. Presented as ASAE Paper
No. 001131, Milwaukee, Wisconsin, July 8-12, 2000.
Mention of a trademark, vendor, or proprietary product does not constitute an
endorsement, guarantee, or warranty of the product by The University of Tennessee,
and does not imply its approval to the exclusion of other products that also may be
suitable.
The author expresses appreciation to the CP Products Co., Inc. for providing a grant to
assist in conducting this research. Chris Christopher and Carolyn Baecker, both of CP
Products Co., Inc., provided extremely helpful consultation on nozzles. Also, Dr. Daniel
Yoder provided valuable insight regarding the phenomenon of decreasing flow rate with
increasing pressure.
The author is Alvin R. Womac, ASAE Member Engineer, Associate Professor, The
University of Tennessee, Agricultural and Biosystems Engineering Department, P.O.
Box 1071, Knoxville, TN 37901, phone : 865.974.7266, fax: 865.974.4514, e-mail:
<awomac@utk.edu>.
17
Figure 1. Cross-section depiction of single orifice flooding nozzle used in the CP 360º
nozzle and CP 3-way nozzle
Figure 2.
Cross-section depiction of two orifices in series used in CP Floater Turbo
nozzle and CP Sprayer Turbo nozzle
18
Figure 3. Photograph of CP 360º nozzle showing orifice plate, 360º deflector, and
positioning of orifice outlets relative to deflector
Figure 4. Photograph of CP 3-Way nozzle showing orifice plate, 3-way deflector, and
position of orifice outlet near the deflector
19
Figure 5. Photograph of CP Floater Turbo nozzle with selectable flood-type tips that
served as secondary orifice and deflector
Figure 6. Photograph of CP Sprayer Turbo nozzle with selectable flood-type tips that
served as secondary orifice and deflector
20
Table 1. Mean droplet size spectra factors for CP 360 nozzle
Orifice
Diameter
(mm)
1.32
1.85
2.31
2.64
3.28
3.76
4.09
4.57
5.31
6.04
6.35
Pressure
(kPa)
Flow rate
(L min-1)
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
1.19
1.48
1.68
1.89
2.35
2.88
3.31
3.69
3.86
4.76
5.38
6.03
4.86
5.95
6.86
7.59
8.09
9.92
11.41
12.64
10.06
12.30
14.12
15.70
11.85
14.40
16.44
18.21
16.08
19.69
22.48
24.97
20.32
24.78
28.52
31.67
25.32
30.96
35.84
39.78
28.08
34.04
39.15
38.23
Mean
Droplet Size Spectra Factor
Dv0.1
Dv0.5
Dv0.9
(μm)
(μm)
(μm)
111
97
91
86
127
119
115
111
153
147
134
131
159
153
146
135
190
163
150
151
172
163
161
155
181
166
166
152
178
170
174
168
194
189
171
162
179
173
163
161
148
146
157
144
412
358
329
302
454
402
381
376
490
464
432
420
503
477
462
453
557
486
467
450
500
474
459
424
495
456
440
421
512
513
511
492
540
524
487
466
520
515
498
502
480
475
497
496
980
804
734
680
922
866
846
809
1029
1000
989
936
1066
1204
1144
1302
1236
875
831
813
884
869
823
831
875
835
898
817
862
887
903
894
993
916
904
881
1044
1044
945
891
881
877
865
866
21
Table 2. Mean droplet size spectra factors for CP 3-way nozzle
Mean
Orifice
Droplet Size Spectra Factor
Diameter
Deflector Pressure Flow rate
Dv0.1
Dv0.5
Dv0.9
-1
(mm)
(kPa)
(L min )
(μm)
(μm)
(μm)
1.32
S
1.85
S
2.31
M
2.64
S
2.64
M
3.28
M
3.76
M
3.76
L
4.09
L
4.57
M
4.57
L
5.31
L
6.04
L
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
207
276
345
138
1.22
1.51
1.74
1.96
2.40
2.97
3.43
3.81
3.40
4.92
5.66
6.27
5.00
6.12
7.04
7.87
5.03
6.14
7.08
7.91
8.22
10.07
11.56
12.81
10.50
12.84
14.76
16.36
10.50
12.86
14.78
16.40
11.94
14.59
16.72
18.33
14.50
17.70
20.40
22.71
14.56
17.79
20.45
22.75
20.81
25.46
29.25
29.08
25.71
124
109
100
94
123
112
106
107
126
119
120
125
136
129
126
136
126
121
118
136
147
160
146
122
161
164
153
124
158
160
159
157
159
166
155
150
158
176
157
131
173
175
175
159
178
174
175
155
190
434
363
327
314
420
374
354
365
464
440
445
485
442
412
413
457
464
445
447
486
503
515
503
393
498
534
516
406
503
504
504
504
505
511
501
474
491
520
498
432
530
518
501
482
517
491
488
462
515
913
752
694
655
800
747
719
702
823
832
830
859
805
770
770
868
823
821
851
875
847
913
941
785
828
1027
1057
786
868
891
860
913
924
885
882
877
876
907
933
854
988
894
856
878
939
901
928
869
928
22
6.35
L
207
276
345
138
207
276
345
31.53
36.37
40.37
28.07
34.22
33.74
33.81
185
176
169
178
183
151
146
506
511
479
501
507
465
462
883
901
861
874
893
876
894
Table 3. Mean droplet size spectra factors for CP Floater Turbo nozzle
Secondary
Mean
Orifice
Orifice
Droplet Size Spectra Factor
Diameter
Diameter Pressure Flow rate
Dv0.1
Dv0.5
Dv0.9
(mm)
(mm)
(kPa)
(L min-1)
(μm)
(μm)
(μm)
1.32
1.85
1.32
2.31
1.85
1.85
1.85
2.31
1.85
2.64
1.85
3.28
2.31
2.95
2.31
3.28
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
1.04
1.28
1.47
1.65
1.80
1.08
1.33
1.54
1.71
1.88
1.75
2.16
2.50
2.79
3.05
2.02
2.51
2.88
3.22
3.53
2.33
2.89
3.34
3.74
4.09
2.48
3.06
3.55
3.97
4.33
2.57
3.17
3.68
4.11
4.50
3.36
4.15
4.78
320
211
167
159
155
425
385
338
279
251
149
131
122
111
105
197
164
152
142
129
263
233
218
212
191
427
360
326
289
275
266
231
216
193
171
300
263
244
844
624
534
502
482
1019
922
814
749
708
462
381
343
310
296
586
522
489
459
396
728
658
610
590
562
915
849
815
765
717
704
625
592
571
554
759
708
652
1349
1122
1095
1020
1016
1398
1373
1337
1312
1292
967
735
665
621
607
1154
1029
960
882
795
1299
1241
1146
1095
1041
1369
1349
1337
1317
1285
1276
1167
1085
1036
1025
1311
1281
1212
23
2.31
3.58
2.64
2.64
2.64
2.95
2.64
3.28
2.64
3.58
3.28
3.28
3.28
3.58
3.28
4.57
3.28
4.98
3.76
4.57
3.76
4.98
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
5.34
5.84
3.44
4.23
4.88
5.45
5.91
3.67
4.53
5.23
5.84
6.40
3.99
4.92
5.70
6.38
6.99
4.38
5.43
6.25
6.97
7.63
4.55
5.60
6.45
7.21
7.87
5.29
6.50
7.49
8.37
9.17
5.50
6.74
7.78
8.69
9.48
6.37
7.84
9.02
10.03
10.95
7.38
9.06
10.41
11.36
12.21
9.21
11.32
13.02
14.52
15.84
9.50
11.68
13.49
229
220
396
354
285
278
260
205
163
147
144
139
228
209
181
172
162
259
240
224
208
197
321
271
254
244
239
239
211
197
184
178
247
241
225
212
198
421
415
385
329
310
434
404
379
352
316
336
274
267
255
248
346
295
271
609
596
882
810
746
726
685
572
515
480
458
444
616
583
548
537
524
697
634
602
588
576
796
717
668
646
634
642
603
584
569
556
653
625
603
594
581
874
857
812
774
753
882
860
809
787
772
797
719
694
652
615
807
727
689
1113
1090
1360
1334
1301
1287
1249
1033
1045
909
855
801
1149
1062
1007
1008
1018
1264
1172
1110
1112
1090
1328
1280
1232
1199
1178
1193
1148
1139
1125
1074
1209
1142
1121
1134
1122
1356
1350
1332
1313
1299
1358
1352
1333
1323
1315
1329
1282
1258
1194
1088
1331
1267
1230
24
4.09
4.57
4.09
4.98
4.57
4.57
4.57
4.98
5.31
6.35
6.04
6.35
6.35
6.35
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
138
207
276
345
414
15.09
16.47
10.52
12.92
14.88
16.62
18.18
10.90
13.45
15.46
17.27
18.83
11.73
14.46
16.70
18.64
20.37
12.68
15.59
17.95
20.04
21.88
20.80
25.45
29.41
32.88
36.19
22.90
27.94
32.29
36.07
39.60
23.09
28.01
31.94
33.97
38.62
257
246
272
256
250
238
231
276
249
238
230
220
259
243
234
222
211
255
237
229
219
208
305
270
252
238
229
283
260
244
223
209
291
258
235
189
183
664
625
703
654
623
642
619
701
645
615
602
584
685
649
615
588
576
653
614
599
574
563
717
625
595
553
537
685
598
575
531
494
716
631
569
483
474
1211
1149
1267
1204
1156
1208
1171
1263
1195
1121
1100
1042
1253
1208
1172
1140
1079
1191
1122
1095
1020
1016
1263
1104
1031
982
941
1229
992
973
989
900
1274
1145
1002
926
950
25
Table 4. Mean droplet size spectra factors for CP Sprayer Turbo nozzle
Secondary
Mean
Orifice
Orifice
Droplet Size Spectra Factor
Diameter
Diameter Pressure Flow rate
Dv0.1
Dv0.5
Dv0.9
-1
(mm)
(mm)
(kPa)
(L min )
(μm)
(μm)
(μm)
1.14
1.85
1.42
1.85
1.85
1.85
1.85
2.95
2.64
2.95
3.58
2.95
3.58
4.39
4.39
4.39
69
138
207
276
69
138
207
276
69
138
207
276
69
138
207
276
69
138
207
276
69
138
207
276
69
138
207
276
69
138
207
276
0.57
0.82
1.00
1.15
0.63
0.89
1.09
1.27
1.16
1.67
2.05
2.35
1.56
2.24
2.72
3.14
2.82
4.08
4.92
5.68
3.51
4.89
5.87
6.75
5.92
8.25
9.96
11.38
6.88
9.58
11.68
13.37
518
420
355
255
436
250
193
164
228
161
151
141
445
375
287
259
289
231
218
205
242
203
184
152
425
348
285
271
373
270
257
247
1062
1006
836
703
1010
694
588
520
652
507
469
431
1029
892
803
741
802
650
617
602
690
586
551
487
905
807
731
697
792
700
680
629
1408
1395
1344
1286
1396
1287
1199
1075
1239
1069
932
835
1400
1363
1334
1309
1334
1235
1193
1183
1274
1160
1091
1033
1366
1332
1291
1268
1322
1267
1250
1180
26
Table 5. Pearson correlation coefficients for CP 360 nozzle
Pearson Correlation Coefficient
(P level)
Nozzle Factor
Dv0.1
Dv0.5
Orifice
Dv0.9
0.677
(< 0.0001)
0.677
(< 0.0001)
-0.008
(0.9240)
Pressure
-0.300
(0.0005)
-0.407
(< 0.0001)
-0.281
(0.0011)
Flow rate
0.517
(< 0.0001)
0.541
(< 0.0001)
-0.088
(0.314)
Table 6. Pearson correlation coefficients for CP 3-way nozzle
Pearson Correlation Coefficient
(P level)
Nozzle Factor
Dv0.1
Dv0.5
Orifice
Dv0.9
0.849
(< 0.0001)
0.646
(< 0.0001)
0.568
(< 0.0001)
Pressure
-0.258
(0.0007)
-0.290
(0.0001)
-0.178
(0.0207)
Flow rate
0.742
(< 0.0001)
0.504
(< 0.0001)
0.468
(< 0.0001)
27
Table 7. Pearson correlation coefficients for CP Floater Turbo nozzle
Pearson Correlation Coefficient
(P level)
Nozzle Factor
Dv0.1
Dv0.5
Dv0.9
Orifice
0.057
(0.2332)
-0.087
(0.0691)
-0.115
(0.0164)
Secondary Orifice
0.319
(< 0.0001)
0.166
(0.0005)
0.116
(0.0153)
Delta Orifice
(Secondary-Orifice)
0.712
(< 0.0001)
0.695
(< 0.0001)
0.637
(< 0.0001)
Pressure
-0.432
(< 0.0001)
-0.446
(< 0.0001)
-0.429
(< 0.0001)
Flow rate
-0.017
(0.7205)
-0.172
(0.0003)
-0.228
(< 0.0001)
Table 8. Pearson correlation coefficients for CP Sprayer Turbo nozzle
Pearson Correlation Coefficient
(P level)
Nozzle Factor
Dv0.1
Dv0.5
Dv0.9
Orifice
-0.142
(0.1691)
-0.215
(0.0353)
-0.074
(0.473)
Secondary Orifice
0.141
(0.1716)
0.083
(0.4240)
0.226
(0.0267)
Delta Orifice
(Secondary-Orifice)
0.573
(< 0.0001)
0.619
(< 0.0001)
0.592
(< 0.0001)
Pressure
-0.594
(< 0.0001)
-0.587
(< 0.0001)
-0.533
(< 0.0001)
-0.127
(0.2174)
-0.194
(0.0588)
-0.054
(0.5985)
Flow rate
28
Table 9. Regression coefficients to predict droplet spectra factors for CP 360 nozzle
Regression Coefficient
(P level)
[Standard Error of Estimate]
Parameter†
Dv0.1
Dv0.5
Dv0.9
Intercept
(μm)
59.21
(< 0.0001)
[8.90]
372.13
(< 0.0001)
[29.07]
1030.46
(< 0.0001)
[134.82]
Orifice
(mm)
63.41
(< 0.0001)
[2.36]
93.02
(< 0.0001)
[7.71]
68.63
(0.0571)
[35.74]
(Orifice)2
(mm2)
-6.75
(< 0.0001)
[0.30]
-9.04
(< 0.0001)
(0.97]
-8.91
(0.0509)
[4.52]
Pressure
(kPa)
-0.186
(0.0092)
[0.071]
-0.649
(0.0056)
[0.230]
-1.454
(0.1759)
[1.068]
(Pressure)2
(kPa2)
0.00018
(0.224)
[0.0001]
0.00076
(0.1120)
[0.0005]
0.00207
(0.3477)
[0.0022]
0.91
0.78
0.11
r2
†
Ranges in Parameters:
Orifice,
Pressure,
1.32 – 6.35 mm
138 – 345 kPa
Table 10. Regression coefficients to predict droplet spectra factors for CP 3-way nozzle
29
Dv0.1
Regression Coefficient
(P level)
[Standard Error of Estimate]
Dv0.5
Dv0.9
Intercept
(μm)
59.22
(< 0.0001)
[9.86]
256.75
(< 0.0001)
[28.64]
566.80
(< 0.0001)
[55.03]
Orifice
(mm)
34.61
(< 0.0001)
[2.68]
110.71
(< 0.0001)
[7.80]
129.41
(< 0.0001)
[14.98]
(Orifice)2
(mm2)
-2.63
(< 0.0001)
[0.34]
-11.27
(< 0.0001)
[0.99]
-12.91
(< 0.0001)
[1.90]
Pressure
(kPa)
0.101
(0.1887)
[0.077]
-0.033
(0.8834)
[0.223]
0.368
(0.3917)
[0.429]
(Pressure)2
(kPa2)
-0.00038
(0.0171)
[0.0002]
-0.0005
(0.2957)
[0.0005]
-0.0011
(0.2032)
[0.0009]
0.85
0.72
0.50
Parameter†
r2
†
Ranges in Parameters:
Orifice,
Pressure,
1.32 – 6.35 mm
138 – 345 kPa
30
Table 11. Regression coefficients to predict droplet spectra factors for CP Floater Turbo
nozzle
Regression Coefficient
(P level)
[Standard Error of Estimate]
Parameter†
Dv0.1
Dv0.5
Dv0.9
Intercept
(μm)
147.69
(< 0.0001)
[19.08]
411.40
(< 0.0001)
[32.85]
704.70
(< 0.0001)
[47.77]
Orifice
(mm)
-195.57
(< 0.0001)
[9.83}
-403.87
(< 0.0001)
[16.93]
-502.40
(< 0.0001)
[24.62]
(Orifice)2
(mm2)
14.59
(< 0.0001)
[1.33]
34.74
(< 0.0001)
[2.29]
46.23
(< 0.0001)
[3.32]
Secondary Orifice
(mm)
254.96
(< 0.0001)
[12.46]
557.94
(< 0.0001)
[21.46]
779.34
(< 0.0001)
[31.20]
(Secondary Orifice)2
(mm2)
-18.54
(< 0.0001)
[1.56]
-48.28
(< 0.0001)
[2.69]
-73.59
(< 0.0001)
[3.91]
Pressure
(kPa)
-0.682
(< 0.0001)
[0.099]
-1.375
(< 0.0001)
[0.171]
-1.553
(< 0.0001)
[0.249]
0.00069
(0.0001)
[0.0002]
0.00148
(< 0.0001)
[0.0003]
0.00156
(0.0005)
[0.0004]
0.81
0.83
0.78
(Pressure)2
(kPa2)
r2
†
Ranges in Parameters:
Orifice,
Secondary Orifice,
Pressure,
1.32 – 6.35 mm
1.85 – 6.35 mm
138 – 414 kPa
31
Table 12. Regression coefficients to predict droplet spectra factors for CP Sprayer
Turbo nozzle
Regression Coefficient
(P level)
[Standard Error of Estimate]
Parameter†
Dv0.1
Dv0.5
Dv0.9
Intercept
(μm)
473.35
(< 0.0001)
[53.76]
836.30
(< 0.0001)
[83.02]
1118.17
(< 0.0001)
[79.33]
Orifice
(mm)
-361.87
(< 0.0001)
[33.27]
-656.91
(< 0.0001)
[51.38]
-550.82
(< 0.0001)
[49.10]
(Orifice)2
(mm2)
46.15
(< 0.0001)
[5.81]
82.10
(< 0.0001)
[8.97]
70.58
(< 0.0001)
[8.57]
Secondary Orifice
(mm)
277.87
(< 0.0001)
[45.54]
651.50
(< 0.0001)
[70.33]
629.85
(< 0.0001)
[67.21]
-25.00
(0.0006)
[7.00]
-69.36
(< 0.0001)
[10.81]
-69.96
(< 0.0001)
[10.33]
-1.794
(< 0.0001)
[0.302]
-2.702
(< 0.0001)
[0.466]
-1.317
(0.0040)
[0.445]
0.003
(0.0007)
[0.0009]
0.0042
(0.0023)
[0.0013]
0.0011
(0.3911)
[0.0013]
0.84
0.87
0.82
(Secondary Orifice)2
(mm2)
Pressure
(kPa)
(Pressure)2
(kPa2)
r2
†
Ranges in Parameters:
Orifice,
Secondary Orifice,
Pressure,
1.14 – 4.39 mm
1.85 – 4.39 mm
69 – 276 kPa