SIST EN ISO 17201-2:2006

2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.Akustik - Geräusche von Schießplätzen - Teil 2: Bestimmung des Mündungsknalls und des Geschossgeräusches durch Berechnung (ISO 17201-2:2006)Acoustique - Bruit des stands de tir - Partie 2: Estimation de la détonation a la bouche et du bruit du projectile par calcul (ISO 17201-2:2006)Acoustics - Noise from shooting ranges - Part 2: Estimation of muzzle blast and projectile sound by calculation (ISO 17201-2:2006)97.220.10Športni objektiSports facilities95.020Vojaška tehnika. Vojaške zadeve. OrožjeMilitary engineering. Military affairs. Weapons17.140.20Emisija hrupa naprav in opremeNoise emitted by machines and equipmentICS:Ta slovenski standard je istoveten z:EN ISO 17201-2:2006SIST EN ISO 17201-2:2006en01-december-2006SIST EN ISO 17201-2:2006SLOVENSKI
STANDARD



SIST EN ISO 17201-2:2006



EUROPEAN STANDARDNORME EUROPÉENNEEUROPÄISCHE NORMEN ISO 17201-2July 2006ICS 97.220.10; 95.020; 17.140.20 English VersionAcoustics - Noise from shooting ranges - Part 2: Estimation ofmuzzle blast and projectile sound by calculation (ISO 17201-2:2006)Acoustique - Bruit des stands de tir - Partie 2: Estimationde la détonation à la bouche et du bruit du projectile parcalcul (ISO 17201-2:2006)Akustik - Geräusche von Schießplätzen - Teil 2:Bestimmung des Mündungsknalls und desGeschossgeräusches durch Berechnung (ISO 17201-2:2006)This European Standard was approved by CEN on 5 June 2006.CEN members are bound to comply with the CEN/CENELEC Internal Regulations which stipulate the conditions for giving this EuropeanStandard the status of a national standard without any alteration. Up-to-date lists and bibliographical references concerning such nationalstandards may be obtained on application to the Central Secretariat or to any CEN member.This European Standard exists in three official versions (English, French, German). A version in any other language made by translationunder the responsibility of a CEN member into its own language and notified to the Central Secretariat has the same status as the officialversions.CEN members are the national standards bodies of Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France,Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania,Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.EUROPEAN COMMITTEE FOR STANDARDIZATIONCOMITÉ EUROPÉEN DE NORMALISATIONEUROPÄISCHES KOMITEE FÜR NORMUNGManagement Centre: rue de Stassart, 36
B-1050 Brussels© 2006 CENAll rights of exploitation in any form and by any means reservedworldwide for CEN national Members.Ref. No. EN ISO 17201-2:2006: ESIST EN ISO 17201-2:2006



EN ISO 17201-2:2006 (E)
2
Foreword
This document (EN ISO 17201-2:2006) has been prepared by Technical Committee ISO/TC 43 "Acoustics" in collaboration with Technical Committee CEN/TC 211 "Acoustics", the secretariat of which is held by DS.
This European Standard shall be given the status of a national standard, either by publication of an identical text or by endorsement, at the latest by January 2007, and conflicting national standards shall be withdrawn at the latest by January 2007.
According to the CEN/CENELEC Internal Regulations, the national standards organizations of the following countries are bound to implement this European Standard: Austria, Belgium, Cyprus, Czech Republic, Denmark, Estonia, Finland, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland and United Kingdom.
Endorsement notice
The text of ISO 17201-2:2006 has been approved by CEN as EN ISO 17201-2:2006 without any modifications.
SIST EN ISO 17201-2:2006



Reference numberISO 17201-2:2006(E)© ISO 2006
INTERNATIONAL STANDARD ISO17201-2First edition2006-07-01Acoustics — Noise from shooting ranges — Part 2: Estimation of muzzle blast and projectile sound by calculation Acoustique — Bruit des stands de tir — Partie 2: Estimation de la détonation à la bouche et du bruit du projectile par calcul
SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) PDF disclaimer This PDF file may contain embedded typefaces. In accordance with Adobe's licensing policy, this file may be printed or viewed but shall not be edited unless the typefaces which are embedded are licensed to and installed on the computer performing the editing. In downloading this file, parties accept therein the responsibility of not infringing Adobe's licensing policy. The ISO Central Secretariat accepts no liability in this area. Adobe is a trademark of Adobe Systems Incorporated. Details of the software products used to create this PDF file can be found in the General Info relative to the file; the PDF-creation parameters were optimized for printing. Every care has been taken to ensure that the file is suitable for use by ISO member bodies. In the unlikely event that a problem relating to it is found, please inform the Central Secretariat at the address given below.
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SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) © ISO 2006 – All rights reserved iiiContents Page Foreword.iv Introduction.v 1 Scope.1 2 Normative references.1 3 Terms and definitions.1 3.1 General.1 3.2 Directivity.5 3.3 Energy.5 3.4 Fraction.7 3.5 Projectile.7 4 Estimation model for source data of the muzzle blast.8 4.1 General.8 4.2 Estimation of chemical energy.9 4.3 Estimation of acoustic energy.9 4.4 Estimation of the Weber energy.9 4.5 Estimation of directivity.9 4.6 Estimation of the spectrum.9 5 Estimation model for projectile sound.10 5.1 General.10 5.2 Estimation of projectile sound source energy.11 6 Sound exposure.12 7 Uncertainty of estimation.15 Annex A (informative)
Simple blast model for estimation of sound energy and its spectrum.16 Annex B (informative)
Quality of input data.18 Annex C (informative)
Examples for estimation of muzzle blast.21 Annex D (informative)
Estimation of sound exposure of projectile according to Figure 3 flowchart — Example.29 Bibliography.31
SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) iv © ISO 2006 – All rights reserved Foreword ISO (the International Organization for Standardization) is a worldwide federation of national standards bodies (ISO member bodies). The work of preparing International Standards is normally carried out through ISO technical committees. Each member body interested in a subject for which a technical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with ISO, also take part in the work. ISO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. International Standards are drafted in accordance with the rules given in the ISO/IEC Directives, Part 2. The main task of technical committees is to prepare International Standards. Draft International Standards adopted by the technical committees are circulated to the member bodies for voting. Publication as an International Standard requires approval by at least 75 % of the member bodies casting a vote. Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. ISO shall not be held responsible for identifying any or all such patent rights. ISO 17201-2 was prepared by Technical Committee ISO/TC 43, Acoustics, Subcommittee SC 1, Noise. ISO 17201 consists of the following parts, under the general title Acoustics — Noise from shooting ranges: ⎯ Part 1: Determination of muzzle blast by measurement ⎯ Part 2: Estimation of muzzle blast and projectile sound by calculation ⎯ Part 4: Prediction of projectile sound The following parts are under preparation: ⎯ Part 3: Guidelines for sound propagation calculations ⎯ Part 5: Noise management The initiative to prepare a standard on impulse noise from shooting ranges was taken by AFEMS, the Association of European Manufacturers of Sporting Ammunition, in April 1996, by the submission of a formal proposal to CEN. After consultation in CEN in 1998, CEN/TC 211, Acoustics, asked ISO/TC 43/SC 1, Noise, to prepare the ISO 17201 series. SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) © ISO 2006 – All rights reserved vIntroduction Two basic sources dominate the shooting sound from firearms: the muzzle blast and the projectile sound. These two sources are basically different. The explosion blast from devices can be treated as muzzle blast. The muzzle blast is caused by the expanding gases of the propellant at the muzzle. The muzzle blast can be modelled based on essentially less spherical volume of these gases at that moment when the expansion speed becomes subsonic. The projectile sound is caused by the supersonic flight of the projectile along the trajectory from the muzzle to the target or to a point on the trajectory where the projectile speed becomes subsonic. The projectile sound stems from a section of the trajectory that coherently radiates a shock wave into a certain direction. In general, the procedures for estimating the source energy depends on the estimation of energies that are involved in related processes. The procedures give estimates for the fraction of these energies that transforms into acoustic energy. The result of the estimation is a set of acoustical source data with respect to energy, direction and frequency content. SIST EN ISO 17201-2:2006



SIST EN ISO 17201-2:2006



INTERNATIONAL STANDARD ISO 17201-2:2006(E) © ISO 2006 – All rights reserved 1Acoustics — Noise from shooting ranges — Part 2: Estimation of muzzle blast and projectile sound by calculation 1 Scope This part of ISO 17201 specifies methods for estimating the acoustic source data of muzzle blast and explosions and the source data of projectile sound on the basis of non-acoustic data for firearms with calibres less than 20 mm and explosions less than 50 g TNT equivalent. This part of ISO 17201 addresses those cases where no source measurements exist or where the data necessary to calculate projectile sound according to ISO 17201-4 are unknown. An example of this situation would be measuring projectile sound from shot guns pellets. This part of ISO 17201 can also be used as an interpolation method between measurements of muzzle blast. Source data are given in terms of spectral angular source energy covering the frequency range from 12,5 Hz to 10 kHz and can be used as data input for sound propagation calculation. This part of ISO 17201 is not applicable to the prediction of sound levels for the assessment of hearing damage and cannot be used to predict sound pressure levels or sound exposure levels below a specific distance where linear acoustics does not apply. 2 Normative references The following referenced documents are indispensable for the application of this document. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies. ISO 17201-1:2005, Acoustics — Noise from shooting ranges — Part 1: Determination of muzzle blast by measurement ISO 17201-4, Acoustics — Noise from shooting ranges — Part 4: Prediction of projectile sound 3 Terms and definitions For the purposes of this document, the terms and definitions given in ISO 17201-1 and the following apply. 3.1 General 3.1.1 air density ρ density of air for the estimation conditions NOTE The air density is expressed in kilograms per cubic metre (kg/m3). SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) 2 © ISO 2006 – All rights reserved 3.1.2 angular frequency ω frequency multiplied by 2π NOTE The angular frequency is expressed in radians per second (rad/s) in all formulae. 3.1.3 coordinate system (x, y) plane coordinate system describing geometry, where the x-axis denotes the line of fire with x = 0 at the muzzle, and the y-axis measures the perpendicular distance from the line of fire in any plane around the line of fire NOTE 1 The sound field of projectile sound is rotational symmetric around the line of fire. NOTE 2 The coordinates are given in metres (m). 3.1.4 cosine-coefficients c1,2…N coefficients of the cosine-transform used to describe the directivity of the angular source energy 3.1.5 deceleration angle ε difference between the radiation angle at the beginning and end of a part of the trajectory NOTE The deceleration angle is expressed in radians (rad) in all formulae. 3.1.6 specific chemical energy u specific chemical energy content of the propellant NOTE The specific chemical energy is usually expressed in joules per kilogram (J/kg) 3.1.7 line of fire continuation of the axis of the barrel See Figure 1. NOTE Ballistic trajectories can be described as a sequence of straight lines. Then the methods apply to each segment. Corrections of the aiming device are ignored. SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) © ISO 2006 – All rights reserved 3 a)
Side or elevation view
b)
Top or plan view Key 1 muzzle 2 barrel 3 sight 4 line of fire 5 line of sight 6 target 7 trajectory 8 height of sight Figure 1 — Line of fire and line of sight 3.1.8 projectile sound source energy Qp acoustic energy from a trajectory length of one metre NOTE 1 The projectile sound source energy is expressed in joules (J). NOTE 2 See also 3.3.6. 3.1.9 propellant mass mc mass of the propellant NOTE The propellant mass is expressed in kilograms (kg). SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) 4 © ISO 2006 – All rights reserved 3.1.10 radiation angle ξ angle between the line of fire and the wave number vector describing the local direction of the propagation of the projectile sound NOTE 1 The radiation angle is expressed in radians (rad) in all formulae. NOTE 2 ξ is the 90° complement of the Mach angle. 3.1.11 angle alpha α angle between the line of fire and a line from the muzzle to the receiver NOTE 1 See ISO 17201-1:2005, Figure 3. NOTE 2 The angle alpha is expressed in radians (rad) in all formulae. 3.1.12 sound exposure E time integral of frequency-weighted squared instantaneous sound pressure over the event duration time ()2 dTEptt=∫ NOTE The sound exposure is expressed in pascal-squared seconds (Pa2⋅s). 3.1.13 sound exposure level LE ten times the logarithm to the base 10 of the ratio of the sound exposure to a reference value NOTE 1 The sound exposure level is expressed in decibels. NOTE 2 See also ISO 1996-1. NOTE 3 The sound exposure level of a single burst of sound or transient sound with duration time is given by the formula ()220010lgdTEptLtpT=⎡⎤⎢⎥⎢⎥⎣⎦∫dB where p(t) is the instantaneous sound pressure as a function of time; p02T0 is the reference value [(20 µPa)2 × 1 s]. 3.1.14 speed of sound in air c speed of sound for the estimation condition NOTE The speed of sound in air is expressed in metres per second (m/s). SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) © ISO 2006 – All rights reserved 53.1.15 divergent area SS size of the area at a certain distance from the trajectory through which the sound radiated from the respective path of the trajectory is propagating NOTE The divergent area is expressed in square metres (m2). 3.1.16 propagation distance rS distance between the source point of projectile sound, PS, and the receiver point, PR, NOTE The propagation distance is expressed in metres (m). 3.1.17 Weber radius RW radius of an equivalent radiating sphere of the “simple model of explosion” NOTE The Weber radius is expressed in metres (m). 3.1.18 Weber pressure pW sound pressure at the surface of the Weber sphere NOTE The Weber pressure is expressed in pascals (Pa). 3.2 Directivity 3.2.1 correction factor due to source directivity cS correction taking into account that different orders of Fourier functions contribute differently to the energy 3.2.2 directivity factor Y(α) directivity function in the direction of α 3.3 Energy 3.3.1 effective angular source energy distribution QY(α) effective energy radiated into the direction α, weighted by directivity NOTE The effective angular source energy distribution is expressed in joules per steradian (J/sr). 3.3.2 total acoustic source energy Qe total acoustic energy after integration of QY(α) over the whole sphere NOTE The total acoustic energy is expressed in joules (J). SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) 6 © ISO 2006 – All rights reserved 3.3.3 energy in the propellant gas Qg energy in the gaseous efflux of the propellant at the muzzle NOTE The energy in the propellant gas is expressed in joules (J). 3.3.4 kinetic energy loss Ql difference in projectile energy of the translatory motion on a part of the trajectory of 1 m length due to air drag NOTE The kinetic energy loss is expressed in joules (J). 3.3.5 muzzle source energy Qm total acoustic energy of the muzzle blast NOTE The muzzle source energy is expressed in joules (J). 3.3.6 projectile sound source energy Qp product of the kinetic energy loss, Ql, and the acoustical efficiency, σac NOTE 1 The projectile sound source energy is expressed in joules (J). NOTE 2 See also 3.1.8. 3.3.7 projectile muzzle kinetic energy Qp0 kinetic energy of the projectile at the muzzle NOTE The projectile muzzle kinetic energy is expressed in joules (J). 3.3.8 propellant energy Qc total chemical energy of the propellant NOTE The propellant energy is expressed in joules (J). 3.3.9 Weber energy density QW energy density of a Weber source with a Weber radius of 1 m NOTE The Weber energy is expressed in joules per cubic metre (J/m3). 3.3.10 reference Weber energy QW,1 Weber energy for a mass of propellant having a Weber radius of 1 m NOTE The reference Weber energy is expressed in joules (J). SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) © ISO 2006 – All rights reserved 73.3.11 angular source energy distribution Sq(α) acoustic energy radiated from the source into the far field per unit solid angle NOTE 1 The acoustic energy radiated by the source within a narrow cone centred around the direction α is d()dqQSαΩ= where Ω is the solid angle in steradian (sr). NOTE 2 The angular source energy distribution is expressed in joules per steradian (J/sr). 3.4 Fraction 3.4.1 kinetic fraction σcp ratio of the projectile kinetic energy, Qp, to propellant energy, Qc NOTE The efficiency is the kinetic fraction, expressed as percentage. 3.4.2 gas fraction σcg ratio of the energy in the exhausted gases, Qg, of the propellant after the shot to the propellant energy, Qc 3.4.3 acoustical efficiency σac ratio of an energy that converts into acoustic energy 3.5 Projectile 3.5.1 projectile diameter dp diameter at the maximum cross section of the projectile NOTE The projectile diameter is expressed in metres (m). 3.5.2 projectile launch speed vp0 speed of the projectile at the muzzle NOTE The projectile launch speed is expressed in metres per second (m/s). 3.5.3 projectile length lp total length of the projectile NOTE The projectile length is expressed in metres (m). SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) 8 © ISO 2006 – All rights reserved 3.5.4 projectile mass mp mass of the projectile, for shotguns the total mass of the pellets NOTE The projectile mass is expressed in kilograms (kg). 3.5.5 projectile speed vp speed of the projectile along the trajectory NOTE The projectile speed is expressed in metres per second (m/s). 3.5.6 projectile speed change κ local change of projectile speed along the trajectory per length unit of trajectory NOTE The projectile speed change is expressed in reciprocal seconds [(m/s)/m = 1/s]. 3.5.7 Mach number M ratio of projectile speed to local sound speed 4 Estimation model for source data of the muzzle blast 4.1 General If possible, the muzzle blast source data should be determined according to ISO 17201-1. This clause specifies methods for the estimation of acoustic source data of muzzle blast and explosions. Firearm muzzle blast is highly directive. Both angular source energy distribution and spectrum vary with angle from the line of fire. For the propagation calculations, frequency and angle-dependent source data are required as input data. Such detailed emission data, measured according to ISO 17201-1, are not readily available for a large variety of weapons and ammunition and there is a need to estimate the data from other technical information. This method may also be applied for explosives. For muzzle blasts, linear acoustics applies if the peak pressure is below 1 kPa. NOTE This method might not be suitable for firearms fitted with muzzle devices that influence the blast field, for example, a muzzle brake that reduces recoil by deflecting propellant gas flow as it exists from muzzle. The method is separated in two parts: firstly, the acoustic energy of the shot shall be estimated; secondly, the directional pattern of the source is to be applied and the spectrum calculated. The procedure allows the use of very general data or, if available, specific data to provide a more accurate result. Therefore, the procedure allows the use of alternatives such as default values or specific values for certain parameters. Due to this flexibility a flow chart is used to describe the steps of the procedure, including equations. In Figure 2 the left part of the flow chart shows how to estimate the muzzle source energy that is to be used in the right part of the flow chart to determine the acoustical source data. Branches in the flow chart that are alternatives are depicted by a logical sign “or”, ⊕. The logical sign for “and”, ⊗, means that both sets of information are needed to continue. The symbol ˆx denotes an default input value for the parameter x. If the parameter x is not known the default value may be used. Numbers at the top of boxes are the equation reference numbers. SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) © ISO 2006 – All rights reserved 9The standard-estimation is to be obtained by following the scheme (see Figure 2) along the given default parameters for all coefficients. This estimation is mandatory for the report. If a different value for any coefficient is used the reason for this shall be stated. 4.2 Estimation of chemical energy The key quantity for estimating the acoustic energy is the total chemical energy involved, Qc. If Qc is not known, two alternatives exist for determining Qc. The left-hand branch uses the kinetic energy of the projectile, Qp0, either known directly or alternatively calculated from the mass and projectile launch speed of the projectile [see Equation (1), in Figure 2]. The projectile energy is a fraction of the total energy. If the fraction σcp is not known, 35 % should be used as default. Equation (2) in Figure 2 then determines Qc. The right hand branch uses the mass of propellant or explosives. The impetus (conversion factor), u, depends on the type of propellant (e.g. 4 310 J/kg for TNT, or 5 860 J/kg for PETN). If the specific chemical energy, u, is not known a value of u = 4 500 J/kg should be used. 4.3 Estimation of acoustic energy The energy Qc is partially converted into heat and into the kinetic energy of the remaining gas (Qg), heat and friction between the barrel and projectile, and the kinetic energy of the projectile (Qp0) or accelerated material, respectively. The inner ballistics, in case of guns, will determine this balance [11]. A fraction of 45 % in Qc should be used as the default value for Qg, the only source of energy in the muzzle blast. Equation (5) accounts for the efficiency of the conversion of energy in the propellant gas, Qg, into the total acoustic energy of the muzzle blast, Qm. 4.4 Estimation of the Weber energy The part on the right of Figure 2 shows the flow chart used to determine the Weber energy, QW, which is the energy density of a Weber source with the Weber radius of 1 m. 4.5 Estimation of directivity For rotational symmetric radiation around the line of fire, the directional pattern of the source is described by a Fourier-series with respect to the angle α relative to the line of fire. If the directivity pattern, cn, is not known, the matrix shown as Equation (6) in Figure 2 gives a list of default values for some weapons. Applying the directivity, Y, to Qe in Equation (10) in Figure 2 yields the energy that flows through the slice, including the directional pattern of the source. 4.6 Estimation of the spectrum The next two steps in Equations (11) and (12) in Figure 2 use an acoustical model of explosions in air which allows an estimation of the Fourier-spectrum of the angular source energy distribution, where α is the direction as described in the Annex A, see also Reference [8]. The default values are validated model parameters and should only be changed if relevant information is available. The integral in Equation (12) should be integrated numerically; there is no known analytical solution. This estimation method should not be used for the prediction of peak pressure values or similar quantities. SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) 10 © ISO 2006 – All rights reserved
NOTE Numbers at above right of the boxes are the numbers of the equations, as referenced in the text. For additional information with regard to Equations (11) and (12), see Annex A. Figure 2 — Flow chart of estimation procedure for muzzle blast source data 5 Estimation model for projectile sound 5.1 General If possible, the projectile sound source data should be determined according to ISO 17201-4. The free field sound exposure level of projectile sound should be calculated using ISO 17201-4. However, ISO 17201-4 is applicable only if the parameters of the shot are known. If this is not the case the following procedure may be used. SIST EN ISO 17201-2:2006



ISO 17201-2:2006(E) © ISO 2006 – All rights reserved 11This estimation procedure assumes that a certain portion of the kinetic energy of the projectile moving with supersonic speed is transferred into a shock wave. The method predicts acoustic energy from the shock wave. From this energy the sound exposure is calculated assuming linear acoustics. For N-waves linear behaviour is assumed if the peak pressure is below 100 Pa. The trajectories are assumed to be a straight line, however, th
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