ASTM D5366-96(2017)
(Test Method)Standard Test Method for Determining the Dynamic Performance of a Wind Vane
Standard Test Method for Determining the Dynamic Performance of a Wind Vane
SIGNIFICANCE AND USE
5.1 This test method will provide a standard for comparison of wind vanes of different types. Specifications by regulatory agencies and industrial societies (3-5) have stipulated performance values. This test method provides an unambiguous method for measuring starting threshold, delay distance, and overshoot ratio.
SCOPE
1.1 This test method covers the determination of the starting threshold, delay distance, and overshoot ratio of a wind vane from direct measurements in a wind tunnel. This test method is applicable only to wind vanes having measurable overshoot.
1.2 This test method provides for determination of the performance of a system consisting of a wind vane and its associated position-to-output transducer in wind tunnel flow. Use of values determined by this test method to describe performance in atmospheric flow of a wind direction measuring system incorporating the vane must be done with an understanding of the differences between the two systems and the two environments.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
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Designation: D5366 − 96 (Reapproved 2017)
Standard Test Method for
Determining the Dynamic Performance of a Wind Vane
This standard is issued under the fixed designation D5366; 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.
1. Scope 3. Terminology
1.1 This test method covers the determination of the starting 3.1 For terms that are not defined herein, refer to Terminol-
threshold, delay distance, and overshoot ratio of a wind vane
ogy D1356.
from direct measurements in a wind tunnel. This test method is
3.2 Definitions:
applicable only to wind vanes having measurable overshoot.
3.2.1 delay distance (D)—the distance the air flows past a
1.2 This test method provides for determination of the
wind vane during the time it takes the vane to return to 50 %
performance of a system consisting of a wind vane and its
of the initial displacement.
associated position-to-output transducer in wind tunnel flow.
3.2.2 overshoot (θ )—the amplitude of a deflection of a
n
Use of values determined by this test method to describe
wind vane as it oscillates about θ after release from an initial
B
performance in atmospheric flow of a wind direction measur-
displacement.
ing system incorporating the vane must be done with an
understanding of the differences between the two systems and
3.2.3 overshoot ratio (Ω)—the ratio of two successive
the two environments.
overshoots, as expressed by the equation:
1.3 The values stated in SI units are to be regarded as Ω 5 θ /θ (1)
~n11! n
standard. No other units of measurement are included in this
where θ and θ are the n and n + 1 overshoots, respec-
n (n+1)
standard.
tively. In practice, since deflections after the first (to the side
1.4 This standard does not purport to address all of the
opposite the release point are normally small, the initial re-
safety concerns, if any, associated with its use. It is the
lease point (that is, the n = 0 deflection) and the first deflec-
responsibility of the user of this standard to establish appro-
tion after release (n = 1) are used in determining the over-
priate safety and health practices and determine the applica-
shoot ratio.
bility of regulatory limitations prior to use.
3.2.4 starting threshold (U )—the lowest speed at which the
o
1.5 This international standard was developed in accor-
vane can be observed or measured moving from a 10° offset in
dance with internationally recognized principles on standard-
a wind tunnel.
ization established in the Decision on Principles for the
Development of International Standards, Guides and Recom- 3.3 Symbols:
mendations issued by the World Trade Organization Technical
D (m) delay distance
U (m/s) starting threshold
Barriers to Trade (TBT) Committee. o
Ω (none) overshoot ratio
η (none) damping ratio
2. Referenced Documents λ (m) damped natural wavelength
d
θ (degrees) overshoot; maximum angular excursion
n
2.1 ASTM Standards: θ (degrees) reference direction
o
θ (degrees) vane equilibrium position
B
D1356 Terminology Relating to Sampling and Analysis of
θ − θ (degrees) dynamic vane bias
B o
Atmospheres
3.4 Calculated or Estimated Values:
3.4.1 damping ratio (η)—calculated from the overshoot
1 ratio (1, 2).
This test method is under the jurisdiction of ASTM Committee D22 on Air
Quality and is the direct responsibility of Subcommittee D22.11 on Meteorology.
ln 1/Ω
~ !
Current edition approved March 15, 2017. Published March 2017. Originally
η 5 (2)
2 2 0.5
~π 1@ln~1/Ω!# !
approved in 1993. Last previous edition approved in 2011 as D5366 – 96 (2011).
DOI: 10.1520/D5366-96R17.
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 boldface numbers in parentheses refer to the list of references at the end of
the ASTM website. this standard.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5366 − 96 (2017)
3.4.2 damped natural wavelength (λ )—at sea level in the 1 % about the mean speed and shall exhibit a turbulence of less
d
U.S. Standard Atmosphere, damped natural wavelength is than 1 %. (Warning— Swirl in the wind tunnel may influence
related to delay distance and damping ratio by the empirical starting threshold measurements. Variations in the measure-
expression (1, 2). ment of θ a low speeds likely indicate the existence of swirl.)
B
6.1.4 Calibration—The mean flow rate shall be verified at
D 6.02 2.4η
~ !
λ 5 (3)
the mandatory speeds of 5 and 10 m/s by use of transfer
d 2 0.5
1 2 η
~ !
standards that have been calibrated by the National Institute of
Standards and Technology (formerly called the National Bu-
4. Summary of Test Method
reau of Standards) or by a fundamental physical method.
4.1 Reference Direction (θ , degrees) is the indicated angu-
o
6.1.4.1 Speeds below 2 m/s for threshold determination
lar position of the vane when aligned along the centerline of the
shall be verified by a sensitive anemometer or by some
wind tunnel.
fundamental time and distance technique, such as measuring
4.2 Vane Equilibrium Position (θ , degrees) is the final
the transition time of smoke puffs, soap bubbles, or heat puffs
B
resting position of the vane after motion in response to an
between two points separated by a known distance.
initial displacement. Ideally, θ = θ .
6.1.5 Environment—The temperature and pressure of the
B o
environment within the wind tunnel test section shall be
4.3 Dynamic Vane Bias (θ − θ , degrees) is the displace-
B o
reported. Differences of greater than 3 % in the density of air
ment of the vane from the wind tunnel centerline at 5 m/s. This
within the test environment may result in poor inter-
measurement will identify wind vanes with unbalanced aero-
comparability of independent measurements of starting
dynamic response because of damage (for example, bent tail)
threshold, delay distance, and overshoot ratio since these
or poor design.
values are density dependent.
4.4 Starting Threshold (U , m/s) is determined by observing
o
6.2 Measuring System:
or measuring the lowest speed at which the vane, released from
6.2.1 Direction—The resolution of the wind vane position-
a 10° offset position in a wind tunnel, moves toward θ .
B
–to–output transducer limits the resolution of the measure-
Movement must be distinguishable from vibration.
ments. The accuracy of the position–to–output conversion shall
4.5 Delay Distance (D, m) may be determined at a number
be within 60.1°. (Warning—Avoid potentiometer dead spots
of wind speeds but shall include 5 m/s and 10 m/s. It is
or crossover positions while performing these procedures.)
computed from the time required for the vane to reach 50 % of
6.2.2 Time—The resolution of time shall be consistent with
the initial displacement from 10° off θ . This time in seconds
B
the distance accuracy required. For this reason, the time
is converted to delay distance by multiplying by the wind
resolution may be changed as the wind tunnel speed is
tunnel speed in metres per second. Tests shall include an equal
changed. For example, for a distance constant measurement to
number of displacements to each side of θ .
B
0.1 m, one must have a time resolution of 0.05 s at 2 m/s and
4.6 Overshoot Ratio (Ω) may be determined at the same
0.01 s at 10 m/s. If time accuracy is based on commercial
time as the delay distance. The maximum angular excursion on electrical power frequency, it will be at least an order of
the opposite side of θ from the initial 10° displacement
magnitude better than the resolution suggested above.
B
fromθ is measured. This value is divided by the initial
B
6.3 Signal Conditioning—Care shall be taken to avoid
displacement to obtain Ω.
electronic circuits in signal conditioning and recording devices
that adversely affect the apparent vane performance.
5. Significance and Use
(Warning—Time constants in signal conditioning and record-
5.1 This test method will provide a standard for comparison
ing devices shall be less than 0.01 s.)
of wind vanes of different types. Specifications by regulatory
6.4 Recording Techniques—The measuring or recording
agencies and industrial societies (3-5) have stipulated perfor-
system shall represent the 10° displacement on each side of θ
B
mance values. This test method provides an unambiguous
with a resolu
...
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: D5366 − 96 (Reapproved 2011) D5366 − 96 (Reapproved 2017)
Standard Test Method for
Determining the Dynamic Performance of a Wind Vane
This standard is issued under the fixed designation D5366; 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.
1. Scope
1.1 This test method covers the determination of the starting threshold, delay distance, and overshoot ratio of a wind vane from
direct measurements in a wind tunnel. This test method is applicable only to wind vanes having measurable overshoot.
1.2 This test method provides for determination of the performance of a system consisting of a wind vane and its associated
position-to-output transducer in wind tunnel flow. Use of values determined by this test method to describe performance in
atmospheric flow of a wind direction measuring system incorporating the vane must be done with an understanding of the
differences between the two systems and the two environments.
1.3 The values stated in SI units are to be regarded as standard. No other units of measurement are included in this standard.
1.4 This standard does not purport to address all of the safety concerns, if any, associated with its use. It is the responsibility
of the user of this standard to establish appropriate safety and health practices and determine the applicability of regulatory
limitations prior to use.
1.5 This international standard was developed in accordance with internationally recognized principles on standardization
established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued
by the World Trade Organization Technical Barriers to Trade (TBT) Committee.
2. Referenced Documents
2.1 ASTM Standards:
D1356 Terminology Relating to Sampling and Analysis of Atmospheres
3. Terminology
3.1 For terms that are not defined herein, refer to Terminology D1356.
3.2 Definitions:
3.2.1 delay distance (D)—the distance the air flows past a wind vane during the time it takes the vane to return to 50 % of the
initial displacement.
3.2.2 overshoot (θ )—the amplitude of a deflection of a wind vane as it oscillates about θ after release from an initial
n B
displacement.
3.2.3 overshoot ratio (Ω)—the ratio of two successive overshoots, as expressed by the equation:
Ω5 θ /θ (1)
~n11! n
where θ and θ are the n and n + 1 overshoots, respectively. In practice, since deflections after the first (to the side op-
n (n+1)
posite the release point are normally small, the initial release point (that is, the n = 0 deflection) and the first deflection after
release (n = 1) are used in determining the overshoot ratio.
3.2.4 starting threshold (U )—the lowest speed at which the vane can be observed or measured moving from a 10° offset in a
o
wind tunnel.
3.3 Symbols:
This test method is under the jurisdiction of ASTM Committee D22 on Air Quality and is the direct responsibility of Subcommittee D22.11 on Meteorology.
Current edition approved Oct. 1, 2011March 15, 2017. Published October 2011March 2017. Originally approved in 1993. Last previous edition approved in 20072011 as
D5366 - 96(2007).D5366 – 96 (2011). DOI: 10.1520/D5366-96R11.10.1520/D5366-96R17.
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.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959. United States
D5366 − 96 (2017)
D (m) delay distance
U (m/s) starting threshold
o
Ω (none) overshoot ratio
η (none) damping ratio
λ (m) damped natural wavelength
d
θ (degrees) overshoot; maximum angular excursion
n
θ (degrees) reference direction
o
θ (degrees) vane equilibrium position
B
θ − θ (degrees) dynamic vane bias
B o
3.4 Calculated or Estimated Values:
3.4.1 damping ratio (η)—calculated from the overshoot ratio (1, 2).
ln 1/Ω
~ !
η5 (2)
2 2 0.5
~π 1@ln~1/Ω!# !
3.4.2 damped natural wavelength (λ )—at sea level in the U.S. Standard Atmosphere, damped natural wavelength is related to
d
delay distance and damping ratio by the empirical expression (1, 2).
D~6.022.4η!
λ 5 (3)
d 2 0.5
12 η
~ !
4. Summary of Test Method
4.1 Reference Direction (θ , degrees) is the indicated angular position of the vane when aligned along the centerline of the wind
o
tunnel.
4.2 Vane Equilibrium Position (θ , degrees) is the final resting position of the vane after motion in response to an initial
B
displacement. Ideally, θ = θ .
B o
4.3 Dynamic Vane Bias (θ − θ , degrees) is the displacement of the vane from the wind tunnel centerline at 5 m/s. This
B o
measurement will identify wind vanes with unbalanced aerodynamic response because of damage (for example, bent tail) or poor
design.
4.4 Starting Threshold (U , m/s) is determined by observing or measuring the lowest speed at which the vane, released from
o
a 10° offset position in a wind tunnel, moves toward θ . Movement must be distinguishable from vibration.
B
4.5 Delay Distance (D, m) may be determined at a number of wind speeds but shall include 5 m/s and 10 m/s. It is computed
from the time required for the vane to reach 50 % of the initial displacement from 10° off θ . This time in seconds is converted
B
to delay distance by multiplying by the wind tunnel speed in metres per second. Tests shall include an equal number of
displacements to each side of θ .
B
4.6 Overshoot Ratio (Ω) may be determined at the same time as the delay distance. The maximum angular excursion on the
opposite side of θ from the initial 10° displacement fromθ is measured. This value is divided by the initial displacement to obtain
B B
Ω.
5. Significance and Use
5.1 This test method will provide a standard for comparison of wind vanes of different types. Specifications by regulatory
agencies and industrial societies (3-5) have stipulated performance values. This test method provides an unambiguous method for
measuring starting threshold, delay distance, and overshoot ratio.
6. Apparatus
6.1 Wind Tunnel (6):
6.1.1 Size—The wind tunnel shall be large enough so that the total projected area of supports, sensor apparatus, and the vane
in its displaced position is less than 5 % of the cross-sectional area of its test section.
6.1.2 Speed Range—The wind tunnel shall have a speed control that will allow the flow rate to be varied from 0 to at least 10
m/s. The speed control shall maintain the flow rate within 60.2 m/s.
6.1.3 Turbulence and Swirl—Across the volume to be occupied by the vane, the flow profile shall vary by no more than 1 %
about the mean speed and shall exhibit a turbulence of less than 1 %. (Warning— Swirl in the wind tunnel may influence starting
threshold measurements. Variations in the measurement of θ a low speeds likely indicate the existence of swirl.)
B
6.1.4 Calibration—The mean flow rate shall be verified at the mandatory speeds of 5 and 10 m/s by use of transfer standards
that have been calibrated by the National Institute of Standards and Technology (formerly called the National Bureau of
Standards) or by a fundamental physical method.
The boldface numbers in parentheses refer to the list of references at the end of this standard.
Available from National Institute of Standards and Technology (NIST), 100 Bureau Dr., Stop 1070, Gaithersburg, MD 20899-1070, http://www.nist.gov.
D5366 − 96 (2017)
6.1.4.1 Speeds below 2 m/s for threshold determination shall be verified by a sensitive anemometer or by some fundamental
time and distance technique, such as measuring the transition time of smoke puffs, soap bubbles, or heat puffs between two points
separated by a known distance.
6.1.5 Environment—The temperature and pressure of the environment within the wind tunnel test section shall be reported.
Differences of greater than 3 % in the density of air within the test environment may result in poor inter-comparability of
independent measurements of starting threshold, delay distance, and overshoot ratio since these values are density dependent.
6.2 Measuring System:
6.2.1 Direction—The resolution of the wind vane position–to–output transducer limits the resolution of the measurements. The
accuracy of the position–to–output
...
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