ASTM E1620-97(2016)
(Terminology)Standard Terminology Relating to Liquid Particles and Atomization
Standard Terminology Relating to Liquid Particles and Atomization
SCOPE
1.1 In a broad sense, this terminology covers terminology associated with liquid particles dispersed in gas. The principal emphasis, however, is on particles produced by the process of atomization.
1.2 All terms, followed by their definitions, are arranged alphabetically. In addition, the terminology contains several tables wherein terms related to specific subjects are segregated and identified.
1.3 Within the broad scope, the following specific categories are included:
1.3.1 Terms pertaining to the structure and condition of individual particles or groups of particles as observed in nature.
1.3.2 Terms pertaining to the structure and condition of individual particles or groups of particles produced by an atomizing device.
1.3.3 Terms pertaining to atomizing devices according to the primary energy source responsible for spray development. (When more than one term is used for the same device or class of devices, the alternative term is followed by the preferred term.) Definitions of the devices may refer to their construction, operating principle, or distinctive spray characteristics. The atomizers, however, are not classified by their respective areas of application or end use. Moreover, the listed terms are generic and do not include brand names, trademarks, or proprietary designations.
1.3.4 Terms pertaining to statistical parameters involving particle measurement, particle size, and size distribution functions.
1.3.5 Terms pertaining to instruments and test procedures utilized in the characterization of liquid particles and sprays.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
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Designation: E1620 − 97 (Reapproved 2016)
Standard Terminology
Relating to Liquid Particles and Atomization
This standard is issued under the fixed designation E1620; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The transformation of bulk liquid into collections of discrete drops in sprays or mists is required for
many processes including combustion, spray drying, evaporative cooling, humidification, and spray
coating. Several techniques are commonly used to measure and characterize collections of drops as
found in sprays, and a substantial body of terminology has evolved to describe liquid drops, drop
populations, sprays, and spray devices, all of which are of interest to the users of liquid atomizers,
spray instruments, and data. This terminology lists terms commonly encountered in the literature on
liquid drops and sprays and provides definitions specific to the subject area.
1. Scope 1.3.4 Terms pertaining to statistical parameters involving
particle measurement, particle size, and size distribution func-
1.1 In a broad sense, this terminology covers terminology
tions.
associated with liquid particles dispersed in gas. The principal
1.3.5 Terms pertaining to instruments and test procedures
emphasis, however, is on particles produced by the process of
utilized in the characterization of liquid particles and sprays.
atomization.
1.4 The values stated in SI units are to be regarded as
1.2 All terms, followed by their definitions, are arranged
standard. No other units of measurement are included in this
alphabetically. In addition, the terminology contains several
standard.
tables wherein terms related to specific subjects are segregated
1.5 This international standard was developed in accor-
and identified.
dance with internationally recognized principles on standard-
1.3 Within the broad scope, the following specific catego-
ization established in the Decision on Principles for the
ries are included:
Development of International Standards, Guides and Recom-
1.3.1 Terms pertaining to the structure and condition of
mendations issued by the World Trade Organization Technical
individualparticlesorgroupsofparticlesasobservedinnature.
Barriers to Trade (TBT) Committee.
1.3.2 Terms pertaining to the structure and condition of
individual particles or groups of particles produced by an
2. Referenced Documents
atomizing device.
2.1 ASTM Standards:
1.3.3 Terms pertaining to atomizing devices according to
D1356 Terminology Relating to Sampling and Analysis of
the primary energy source responsible for spray development.
Atmospheres
(When more than one term is used for the same device or class
E799 Practice for Determining Data Criteria and Processing
of devices, the alternative term is followed by the preferred
for Liquid Drop Size Analysis
term.) Definitions of the devices may refer to their
construction, operating principle, or distinctive spray charac-
3. Terminology
teristics. The atomizers, however, are not classified by their
respective areas of application or end use. Moreover, the listed
aerating nozzle, n—a device to atomize liquid for the purpose
terms are generic and do not include brand names, trademarks,
of aeration.
or proprietary designations.
DISCUSSION—Although this term is occasionally used to designate
certain types of airblast or internal mixing pneumatic atomizers, it is
ambiguous and is not recommended for describing the latter devices.
This terminology is under the jurisdiction ofASTM Committee E29 on Particle
and Spray Characterization and is the direct responsibility of Subcommittee E29.02
on Non-Sieving Methods. For referenced ASTM standards, visit the ASTM website, www.astm.org, or
Current edition approved Oct. 1, 2016. Published October 2016. Originally contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM
approved in 1994. Last previous edition approved in 2012 as E1620 – 97 (2012). Standards volume information, refer to the standard’s Document Summary page on
DOI: 10.1520/E1620-97R16. the ASTM website.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1620 − 97 (2016)
TABLE 1 Summary of Atomizer Terms
Pressure Atomizer (hydraulic atomizer, pressure atomizing nozzle, Lubbock nozzle
pressure nozzle, single-fluid atomizer) variable orifice poppet nozzle (variable orifice pintle nozzle)
cone atomizer (cone spray nozzle)
hollow cone atomizer Pneumatic Atomizer (air atomizing nozzle, blast nozzle, gas atomizer, gas-
solid cone atomizer (full cone nozzle) liquid nozzle, twin-fluid atomizer, two-fluid atomizer)
deflector atomizer (flood nozzle, flooding nozzle) air assist nozzle
dual orifice nozzle (duple nozzle) airblast nozzle (air blast nozzle,
duplex nozzle aerating nozzle)
piloted airblast nozzle (simplex airblast nozzle)
Fan Spray Atomizer: prefilming airblast nozzle
even spray atomizer (even flow atomizer)
flat spray atomizer (flat jet atomizer) External Mixing Pneumatic Atomizer
Laskin nozzle
Fog Nozzle
Internal Mixing Pneumatic Atomizer
Impact Atomizer: (impingement atomizer): (aerating nozzle,
pintle atomizer Nukiyama-Tanasawa nozzle,
splash cup atomizer effervescent atomizer)
splash plate atomizer
Centrifugal Atomizer (rotary atomizer, slinger)
Impinging Jet Atomizer (impingement atomizer): rotary cup atomizer (spinning cup atomizer)
doublet atomizer rotary disk atomizer (spinning disk atomizer)
triplet atomizer rotary wheel atomizer
Plain Jet Atomizer (orifice atomizer, plain orifice atomizer, single jet atomizer, Vibratory Atomizer (vibrative atomizer)
straight stream nozzle) electromagnetic vibratory atomizer
simplex nozzle piezoelectric vibratory atomizer
Square Spray Nozzle Berglund-Liu atomizer
sonic nozzle
Swirl Atomizer ultrasonic nozzle
Swirl Chamber Atomizer (centrifugal pressure nozzle, swirl chamber vibrating needle atomizer
atomizer) vibrating reed atomizer
by-pass nozzle (bypass nozzle, flowback nozzle, recirculating nozzle, return
flow nozzle, spill nozzle, spill return nozzle, spillback nozzle) Electrostatic Atomizer
dual orifice nozzle (duplex nozzle)
duplex nozzle Shear Coaxial Injector
simplex nozzle swirl coaxial injector
variable-area nozzle
Siphon Nozzle (aspirating nozzle)
Sonic Nozzle (sonic-whistle atomizer, ultrasonic nozzle)
TABLE 2 Characteristic Particle Diameters and Distribution
air assist nozzle, n—a pneumatic atomizer in which pressur-
Functions
ized air is utilized to enhance the atomization produced by
Aerodynamic Diameter
pressurized liquid. The air may be required only for part of
Area (surface) Mean Diameter
the operating range (for example, low liquid flow rates).
D , D , D , D
Nf Lf Af Vf
De Brouckere Diameter
air atomizing nozzle, n—see pneumatic atomizer.
Equivalent Volume Sphere
Diameter
air blast nozzle, n—see airblast nozzle.
Evaporative Diameter
airblast nozzle, n—a pneumatic atomizer that utilizes a rela-
Herdan Diameter
Linear (arithmetic) Mean Diameter
tively large volume of low-pressure air.
Log Normal Distribution
DISCUSSION—The term is occasionally used to designate the entire
Mean Diameters
class of pneumatic atomizers.
Normal Distribution
Nukiyama-Tanasawa Distribution
aspirating nozzle, n—see siphon nozzle.
Relative Span
Rosin-Rammler Distribution
atomization, n—the process of atomizing.
Sauter Mean Diameter
Square Root Normal Distribution
atomize, v—to transform bulk liquid or slurry into particles.
Stokes’ Diameter
Upper Limit Log Normal
atomizer, n—a device for atomizing.
Distribution
Volume Mean Diameter
Berglund-Liu atomizer, n—a vibratory atomizer in which a
piezoelectric transducer transmits high-frequency oscilla-
tions to a liquid stream discharged through an orifice,
aerodynamic diameter, n—the diameter of a hypothetical
creating relatively uniform drops whose size is a function of
sphere having a specific gravity of unity and the same
the frequency of oscillation and the flow rate of the liquid
settling velocity as the actual particle.
through the orifice.
aerosol, n—a dispersion of solid particles or liquid particles, or
both, in gaseous media. D1356 blast nozzle, n—see pneumatic atomizer.
E1620 − 97 (2016)
DISCUSSION—For sprays whose drop size distributions are axisym-
breakup, n—liquid disintegration that occurs during atomiza-
metric in space, anAbel inversion procedure has been used to perform
tion.
3,4
the deconvolution.
breakup length, n—the distance between the liquid discharge
deflector atomizer, n—an atomizer in which a liquid jet
point of an atomizing device and the point where liquid
spreads out over a solid surface, forming a spray whose
breakup commences.
shape depends upon the solid surface.
bypass nozzle, n—see by-pass nozzle.
dispersion, n—a system of particles distributed in a solid,
by-pass nozzle, n—a swirl chamber atomizer containing by-
liquid, or gas.
pass orifice(s) or port(s) through which part of the inlet
liquid may be withdrawn from the swirl chamber and
dispersion, n—the spread of values of a frequency distribution
returned to the supply tank or pressure pump suction. The
about an average (in statistics). (Quantitative measures of
discharge flow is modulated by controlling the pressure in
dispersion include range, variance, standard deviation, mean
the bypass line, using a valve in the line.
deviation, and relative span.)
cavitation, n—the formation of vapor-filled cavities in the
doublet injector, n—an impinging jet atomizer in which there
interiororonthesolidboundariesofliquidsinmotionwhere
are two colliding liquid jets.
thepressureisreducedtoacriticalvaluewithoutachangein
drop, n—a single liquid particle having a generally spheroidal
ambient temperature.
shape.
centrifugal atomizer, n—a device wherein a rotating solid
droplet, n—see drop; also a small drop.
surface is the primary source of energy utilized to produce a
dual orifice nozzle, n—a swirl chamber atomizer containing a
spray.
primaryinjectorandaconcentricannularsecondaryinjector,
DISCUSSION—Alternatively, an atomizer that rotates to distribute the
liquid. each injector comprising a separate orifice and set of
tangential slots. The nozzle is normally operated only with
centrifugal pressure nozzle, n—see swirl chamber atomizer.
the primary injector at low flow rates, with secondary liquid
circumferential patternation, n—measurements taken in a
introduced at a specified pressure. (This definition applies to
circumferential direction, showing the variation in liquid
devices used in the gas turbine industry.)
flux about the nozzle axis.
duple nozzle, n—see dual orifice nozzle.
cloud, n—any collection of particulate matter in the atmo-
duplex nozzle, n—a swirl chamber atomizer comprising a
sphere dense enough to be perceptible to the eye, especially
single discharge orifice and two sets of tangential slots, each
a collection of water drops. D1356
with a separately controlled liquid supply. The smaller
coalescence, n—the merging of two or more liquid particles to
(primary) slots supply liquid at low flow rates, and both sets
form a single liquid particle.
(primary and secondary) are utilized as flow increases.
concentration, n—see number density.
effervescent atomizer, n—an internal mixing pneumatic atom-
cone atomizer, n—an atomizer that produces a conical spray
izer in which gas bubbles are dispersed in the liquid stream.
pattern.
electromagnetic vibratory atomizer, n—a vibratory atomizer
cone pattern, n—a diverging spray pattern that is nominally
in which an electromagnetic transducer transmits high-
symmetric about the nozzle axis and whose apex is located
frequency oscillations to the liquid.
at or near the nozzle discharge orifice.
electrostatic atomizer, n—a device wherein an electric charge
cone spray nozzle, n—see cone atomizer.
is the primary source of energy utilized to produce a spray.
convolution, n—the combination of local measurements of
emitting spray angle, n—see initial spray angle.
drop size distribution and number density into equivalent
line-of-sight values of drop size distribution and optical
equivalent volume sphere diameter, n—the diameter of a
extinction.
hypothetical sphere having the same volume as the actual
particle.
D ,D ,D ,D , n—diameters such that the cumulative
Nf Lf Af Vf
number of particles, (N), length of diameter, (L), surface
even flow atomizer, n—see even spray atomizer.
area, (A), or volume, (V), from zero diameter to these
even spray atomizer, n—a fan spray atomizer that produces a
respective diameters is the fraction, (f), of the corresponding
relatively uniform band of liquid, usually by means of
sum for the total distribution.
Example—D is the volume median diameter; that is,
V0.5
50 % of the total volume of liquid is in drops of smaller
Hammond, D.C., “A Deconvolution Technique for Line-Of-Sight Optical
diameter and 50 % is in drops of larger diameter.
Scattering Measurements in Axisymmetric Sprays,” Applied Optics, Vol 20, No. 3,
February 1981, pp. 493–499.
deconvolution, n—a procedure by which line-of-sight mea-
Yule, A.J., Ah Seng, C., Felton, P.G., Ungut, A., and Chigier, N.A., “A Laser
surements of drop size distribution and optical extinction are
Tomographic Investigation of Liquid Fuel Sprays,” Eighteenth Symposium-
converted into local representations of the distribution and
International-on Combustion, Pittsburgh: The Combustion Institute, 1981, pp.
number density. 1501–1510.
E1620 − 97 (2016)
injection, through an elliptical orifice. (This definition ap- impingement atomizer, n—in rocketry, an impinging jet
plies to devices utilized in the agricultural industry.) atomizer; in industrial processing, an impact atomizer.
DISCUSSION—Sincethistermisambiguous,itisnotrecommendedfor
external mixing pneumatic atomizer, n—a pneumatic atom-
describing either device.
izer in which pressurized gas is directed on a liquid film or
impinging jet atomizer, n—a pressure atomizer in which
jet outside the nozzle, so as to form a spray.
atomization is achieved by the external collision of two or
fan pattern, n—a spray pattern in which the liquid flux is
more liquid jets.
concentrated in a narrow oval or ellipse in a plane perpen-
initial spray angle, n—the plane angle of the spray emerging
dicular to the spray axis.
from the nozzle discharge orifice.
fan spray atomizer, n—apressureatomizerthatproducesaflat
internal mixing pneumatic atomizer, n—a pneumatic atom-
sheet of liquid that collapses into particles. The angle or
izer in which gas and liquid are introdu
...
This document is not an ASTM standard and is intended only to provide the user of an ASTM standard an indication of what changes have been made to the previous version. Because
it may not be technically possible to adequately depict all changes accurately, ASTM recommends that users consult prior editions as appropriate. In all cases only the current version
of the standard as published by ASTM is to be considered the official document.
Designation: E1620 − 97 (Reapproved 2012) E1620 − 97 (Reapproved 2016)
Standard Terminology
Relating to Liquid Particles and Atomization
This standard is issued under the fixed designation E1620; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision. A number in parentheses indicates the year of last reapproval. A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
INTRODUCTION
The transformation of bulk liquid into collections of discrete drops in sprays or mists is required for
many processes including combustion, spray drying, evaporative cooling, humidification, and spray
coating. Several techniques are commonly used to measure and characterize collections of drops as
found in sprays, and a substantial body of terminology has evolved to describe liquid drops, drop
populations, sprays, and spray devices, all of which are of interest to the users of liquid atomizers,
spray instruments, and data. This terminology lists terms commonly encountered in the literature on
liquid drops and sprays and provides definitions specific to the subject area.
1. Scope
1.1 In a broad sense, this terminology covers terminology associated with liquid particles dispersed in gas. The principal
emphasis, however, is on particles produced by the process of atomization.
1.2 All terms, followed by their definitions, are arranged alphabetically. In addition, the terminology contains several tables
wherein terms related to specific subjects are segregated and identified.
1.3 Within the broad scope, the following specific categories are included:
1.3.1 Terms pertaining to the structure and condition of individual particles or groups of particles as observed in nature.
1.3.2 Terms pertaining to the structure and condition of individual particles or groups of particles produced by an atomizing
device.
1.3.3 Terms pertaining to atomizing devices according to the primary energy source responsible for spray development. (When
more than one term is used for the same device or class of devices, the alternative term is followed by the preferred term.)
Definitions of the devices may refer to their construction, operating principle, or distinctive spray characteristics. The atomizers,
however, are not classified by their respective areas of application or end use. Moreover, the listed terms are generic and do not
include brand names, trademarks, or proprietary designations.
1.3.4 Terms pertaining to statistical parameters involving particle measurement, particle size, and size distribution functions.
1.3.5 Terms pertaining to instruments and test procedures utilized in the characterization of liquid particles and sprays.
1.4 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
2. Referenced Documents
2.1 ASTM Standards:
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
E799 Practice for Determining Data Criteria and Processing for Liquid Drop Size Analysis
3. Terminology
aerating nozzle, n—a device to atomize liquid for the purpose of aeration.
This terminology is under the jurisdiction of ASTM Committee E29 on Particle and Spray Characterization and is the direct responsibility of Subcommittee E29.02 on
Non-Sieving Methods.
Current edition approved April 1, 2012Oct. 1, 2016. Published May 2012October 2016. Originally approved in 1994. Last previous edition approved in 20042012 as
E1620 – 97 (2004).(2012). DOI: 10.1520/E1620-97R12.10.1520/E1620-97R16.
For referenced ASTM standards, visit the ASTM website, www.astm.org, or contact ASTM Customer Service at service@astm.org. For Annual Book of ASTM Standards
volume information, refer to the standard’s Document Summary page on the ASTM website.
DISCUSSION—
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
E1620 − 97 (2016)
TABLE 1 Summary of Atomizer Terms
Pressure Atomizer (hydraulic atomizer, pressure atomizing nozzle, Lubbock nozzle
pressure nozzle, single-fluid atomizer) variable orifice poppet nozzle (variable orifice pintle nozzle)
cone atomizer (cone spray nozzle)
hollow cone atomizer Pneumatic Atomizer (air atomizing nozzle, blast nozzle, gas atomizer, gas-
solid cone atomizer (full cone nozzle) liquid nozzle, twin-fluid atomizer, two-fluid atomizer)
deflector atomizer (flood nozzle, flooding nozzle) air assist nozzle
dual orifice nozzle (duple nozzle) airblast nozzle (air blast nozzle,
duplex nozzle aerating nozzle)
piloted airblast nozzle (simplex airblast nozzle)
Fan Spray Atomizer: prefilming airblast nozzle
even spray atomizer (even flow atomizer)
flat spray atomizer (flat jet atomizer) External Mixing Pneumatic Atomizer
Laskin nozzle
Fog Nozzle
Internal Mixing Pneumatic Atomizer
Impact Atomizer: (impingement atomizer): (aerating nozzle,
pintle atomizer Nukiyama-Tanasawa nozzle,
splash cup atomizer effervescent atomizer)
splash plate atomizer
Centrifugal Atomizer (rotary atomizer, slinger)
Impinging Jet Atomizer (impingement atomizer): rotary cup atomizer (spinning cup atomizer)
doublet atomizer rotary disk atomizer (spinning disk atomizer)
triplet atomizer rotary wheel atomizer
Plain Jet Atomizer (orifice atomizer, plain orifice atomizer, single jet atomizer, Vibratory Atomizer (vibrative atomizer)
straight stream nozzle) electromagnetic vibratory atomizer
simplex nozzle piezoelectric vibratory atomizer
Square Spray Nozzle Berglund-Liu atomizer
sonic nozzle
Swirl Atomizer ultrasonic nozzle
Swirl Chamber Atomizer (centrifugal pressure nozzle, swirl chamber vibrating needle atomizer
atomizer) vibrating reed atomizer
by-pass nozzle (bypass nozzle, flowback nozzle, recirculating nozzle, return
flow nozzle, spill nozzle, spill return nozzle, spillback nozzle) Electrostatic Atomizer
dual orifice nozzle (duplex nozzle)
duplex nozzle Shear Coaxial Injector
simplex nozzle swirl coaxial injector
variable-area nozzle
Siphon Nozzle (aspirating nozzle)
Sonic Nozzle (sonic-whistle atomizer, ultrasonic nozzle)
TABLE 2 Characteristic Particle Diameters and Distribution
Functions
Aerodynamic Diameter
Area (surface) Mean Diameter
D D D D
Nf, Lf, Af, Vf
De Brouckere Diameter
Equivalent Volume Sphere
Diameter
Evaporative Diameter
Herdan Diameter
Linear (arithmetic) Mean Diameter
Log Normal Distribution
Mean Diameters
Normal Distribution
Nukiyama-Tanasawa Distribution
Relative Span
Rosin-Rammler Distribution
Sauter Mean Diameter
Square Root Normal Distribution
Stokes’ Diameter
Upper Limit Log Normal
Distribution
Volume Mean Diameter
Although this term is occasionally used to designate certain types of airblast or internal mixing pneumatic atomizers, it is ambiguous and is not
recommended for describing the latter devices.
aerodynamic diameter, n—the diameter of a hypothetical sphere having a specific gravity of unity and the same settling velocity
as the actual particle.
E1620 − 97 (2016)
aerosol, n—a dispersion of solid particles or liquid particles, or both, in gaseous media. D1356
air assist nozzle, n—a pneumatic atomizer in which pressurized air is utilized to enhance the atomization produced by pressurized
liquid. The air may be required only for part of the operating range (for example, low liquid flow rates).
air atomizing nozzle,n—see pneumatic atomizer.
air blast nozzle,n—see airblast nozzle.
airblast nozzle, n—a pneumatic atomizer that utilizes a relatively large volume of low-pressure air.
DISCUSSION—
The term is occasionally used to designate the entire class of pneumatic atomizers.
aspirating nozzle,n—see siphon nozzle.
atomization, n—the process of atomizing.
atomize, v—to transform bulk liquid or slurry into particles.
atomizer, n—a device for atomizing.
Berglund-Liu atomizer, n—a vibratory atomizer in which a piezoelectric transducer transmits high-frequency oscillations to a
liquid stream discharged through an orifice, creating relatively uniform drops whose size is a function of the frequency of
oscillation and the flow rate of the liquid through the orifice.
blast nozzle,n—see pneumatic atomizer.
breakup, n—liquid disintegration that occurs during atomization.
breakup length, n—the distance between the liquid discharge point of an atomizing device and the point where liquid breakup
commences.
bypass nozzle,n—see by-pass nozzle.
by-pass nozzle, n—a swirl chamber atomizer containing by-pass orifice(s) or port(s) through which part of the inlet liquid may
be withdrawn from the swirl chamber and returned to the supply tank or pressure pump suction. The discharge flow is modulated
by controlling the pressure in the bypass line, using a valve in the line.
cavitation, n—the formation of vapor-filled cavities in the interior or on the solid boundaries of liquids in motion where the
pressure is reduced to a critical value without a change in ambient temperature.
centrifugal atomizer, n—a device wherein a rotating solid surface is the primary source of energy utilized to produce a spray.
DISCUSSION—
Alternatively, an atomizer that rotates to distribute the liquid.
centrifugal pressure nozzle,n—see swirl chamber atomizer.
circumferential patternation, n—measurements taken in a circumferential direction, showing the variation in liquid flux about
the nozzle axis.
cloud, n—any collection of particulate matter in the atmosphere dense enough to be perceptible to the eye, especially a collection
of water drops. D1356
coalescence, n—the merging of two or more liquid particles to form a single liquid particle.
concentration,n—see number density.
cone atomizer, n—an atomizer that produces a conical spray pattern.
cone pattern, n—a diverging spray pattern that is nominally symmetric about the nozzle axis and whose apex is located at or near
the nozzle discharge orifice.
cone spray nozzle,n—see cone atomizer.
convolution, n—the combination of local measurements of drop size distribution and number density into equivalent line-of-sight
values of drop size distribution and optical extinction.
D , D , D , D , n—diameters such that the cumulative number of particles, (N), length of diameter, (L), surface area, (A), or
Nf Lf Af Vf
volume, (V), from zero diameter to these respective diameters is the fraction, (f), of the corresponding sum for the total
distribution.
Example—D is the volume median diameter; that is, 50 % of the total volume of liquid is in drops of smaller diameter
V0.5
and 50 % is in drops of larger diameter.
E1620 − 97 (2016)
deconvolution, n—a procedure by which line-of-sight measurements of drop size distribution and optical extinction are converted
into local representations of the distribution and number density.
DISCUSSION—
3,4
For sprays whose drop size distributions are axisymmetric in space, an Abel inversion procedure has been used to perform the deconvolution.
deflector atomizer, n—an atomizer in which a liquid jet spreads out over a solid surface, forming a spray whose shape depends
upon the solid surface.
dispersion, n—a system of particles distributed in a solid, liquid, or gas.
dispersion, n—the spread of values of a frequency distribution about an average (in statistics). (Quantitative measures of
dispersion include range, variance, standard deviation, mean deviation, and relative span.)
doublet injector, n—an impinging jet atomizer in which there are two colliding liquid jets.
drop, n—a single liquid particle having a generally spheroidal shape.
droplet, n—see drop; also a small drop.
dual orifice nozzle, n—a swirl chamber atomizer containing a primary injector and a concentric annular secondary injector, each
injector comprising a separate orifice and set of tangential slots. The nozzle is normally operated only with the primary injector
at low flow rates, with secondary liquid introduced at a specified pressure. (This definition applies to devices used in the gas
turbine industry.)
duple nozzle,n—see dual orifice nozzle.
duplex nozzle, n—a swirl chamber atomizer comprising a single discharge orifice and two sets of tangential slots, each with a
separately controlled liquid supply. The smaller (primary) slots supply liquid at low flow rates, and both sets (primary and
secondary) are utilized as flow increases.
effervescent atomizer, n—an internal mixing pneumatic atomizer in which gas bubbles are dispersed in the liquid stream.
electromagnetic vibratory atomizer, n—a vibratory atomizer in which an electromagnetic transducer transmits high-frequency
oscillations to the liquid.
electrostatic atomizer, n—a device wherein an electric charge is the primary source of energy utilized to produce a spray.
emitting spray angle,n—see initial spray angle.
equivalent volume sphere diameter, n—the diameter of a hypothetical sphere having the same volume as the actual particle.
even flow atomizer,n—see even spray atomizer.
even spray atomizer, n—a fan spray atomizer that produces a relatively uniform band of liquid, usually by means of injection,
through an elliptical orifice. (This definition applies to devices utilized in the agricultural industry.)
external mixing pneumatic atomizer, n—a pneumatic atomizer in which pressurized gas is directed on a liquid film or jet outside
the nozzle, so as to form a spray.
fan pattern, n—a spray pattern in which the liquid flux is concentrated in a narrow oval or ellipse in a plane perpendicular to the
spray axis.
fan spray atomizer, n—a pressure atomizer that produces a flat sheet of liquid that collapses into particles. The angle or width
of the sheet is controlled by the shape of a slot or oval discharge orifice, by an external deflector, or by impinging jets.
flat jet atomizer,n—see flat spray atomizer.
flat spray atomizer, n—a fan spray atomizer that produces a planar spray pattern.
Hammond, D.C., “A Deconvolution Technique for Line-Of-Sight Optical Scattering Measurements in Axisymmetric Sprays,” Applied Optics, Vol 20, No. 3, February
1981, pp. 493–499.
Yule, A.J., Ah Seng, C., Felton, P.G., Ungut, A., and Chigier, N.A., “A Laser Tomographic Investigation of Liquid Fuel Sprays,” Eighteenth Symposium-International-on
Combustion, Pittsburgh: The Combustion Institute, 1981, pp. 1501–1510.
DISCUSSION—
In agricultural applications, the spray patterns have tapered edges.
flood nozzle,n—see deflector atomizer.
E1620 − 97 (2016)
flooding nozzle,n—see deflector a
...
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