• Title/Summary/Keyword: Shooting Noise

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Analysis of Acoustic Characteristics and Shooting Noise Prediction for Shooting Range Soundproofing in Military (군부대 방음사격장의 음향특성 분석 및 사격소음 예측)

  • Jeong, A-Yeong;Kim, Jae-Soo
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.24 no.11
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    • pp.833-839
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    • 2014
  • The shooting noise caused by shooting training, which has strength and impacts, is becoming a serious damage to the residents around the shooting range and, consequently, the number of civil appeals against the shooting noise is on the constant increase. For this reason, the military examines the effects of the shooting noise at the stage of design in constructing a shooting range and tries to build a soundproof shooting range to minimize civil appeals. However, the lack of research and data concerning propagation and attenuation, both of which characterize the shooting noise from within a soundproof shooting range, even makes it so difficult to design a soundproof shooting range in constructing it. So this study used an acoustic simulation in a soundproof shooting range to identify acoustic and propagation characteristics within the shooting range and, on this basis, predicted the noise level at an exit of the soundproof shooting range. As a result, if the form and specifications of a soundproof shooting range were decided on at the stage of design, it was possible to use a simulation to design a soundproof shooting range with optimized acoustic performance and, on this basis, to predict a sound pressure level at an exit of the soundproof shooting range. On the basis of these data, it is probably possible to determine the degree of the effects of the shooting noise on the villages around a shooting range and the extent of damage to it and to minimize civil appeals against the shooting noise and resolve the issues of compensation and agreement with ease. This study is expected to provide useful data for designing and constructing a similar soundproof shooting range.

Numerical analysis of the impulsive noise generation and propagation using high order scheme (고차의 수치적 기법을 적용한 충격소음의 생성 및 전파 해석)

  • Kim, Min-Woo;Kim, Sung-Tae;Kim, Kyu-Hong;Lee, Soo-Gab
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2007.11a
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    • pp.1494-1498
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    • 2007
  • Impulsive shooting noise is basically complex phenomenon which contains the linear and non-linear characteristics. For those reasons, numerical analysis of impulsive shooting noise has the difficulties in control of the numerical stability and accuracy on the simulation. In this research, Wave-number Extended Finite Volume Scheme (WEFVS) is applied to the numerical analysis of impulsive shooting noise. In the muzzle blast flow simulation, the generation of the precursor wave and the induced vortex ring are observed. Consequently, blast wave. vortex ring interaction and vortex ring. bow shock wave interaction are evaluated on the shooting process using the accurate and stable scheme. The sound generation in the interactions can be explained by the vorticity transport theorem. The shear layer is evolved behind the projectiles due to the jet flow. In these computations, the impulsive shooting noise is generated by the complex interaction with shooting process and is propagated to the far-field boundary. The impulsive shooting noise generation can be observed by the applications of WEFVS and analyzed by the physical phenomena.

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Measurement of Noise and Evaluation of Noise Control Methods for Military Rifle Shooting Ranges (군 소화기 사격장 소음측정 및 소음저감 방안 평가)

  • Lee, Sang-Woo;Kim, Hee-Seok;Jeong, Sang-Jo
    • Journal of the Korea Institute of Military Science and Technology
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    • v.12 no.1
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    • pp.123-132
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    • 2009
  • Civil petitions and law suits against the military rifle shooting noise have been increased because many military shooting ranges are located near civilian residential area. In order to solve the noise problems, military have devised various methods. In this study, propagation properties of rifle shot through atmosphere were investigated. The military rifle shooting noise level at 5m from muzzle was between $l14{\sim}120dB$ in all directions. The noise level loom both backward and sideward away from system firing range consisting lines of 8 shooting locations were 90dB, when shots were all fired within 10 seconds. At present some of military bases established sound barriers, muzzle enclosures, silencers, and indoor shooting ranges to reduce noises and these prevention methods can reduce noise by $5{\sim}20dB,\;5{\sim}9dB,\;5{\sim}13dB,\;40{\sim}50dB$, respectively. Even though indoor shooting range has the best performance, it requires very expensive construction cost and has short length between target and shooter. In comparison, muzzle enclosure is cheap, but because it is installed in fixed position it can only be used in one shooting position. Therefore a commander should select appropriate methods to reduce military rifle shooting noise considering distance from residential area to the range, mission of military training, budget, etc.

An Experimental Study on Shielding Apparatus for the Impulse Noise of K2 Rifle (K2소총의 사격음 차폐장치에 관한 실험적 연구)

  • Lee, Jin-Ho
    • Journal of the Korea Institute of Military Science and Technology
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    • v.13 no.3
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    • pp.486-492
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    • 2010
  • This paper studies an experimental analysis of the impulse noise of K2 rifle when its bullet passes through the large tube(length 1.84m, outer diameter 50cm, glass wool & steel). In experiment, the characteristics of the sound of shooting were different according to the way of shooting; the results of the experiment are given below. First of all, the shooting sound was lower in single-shot shooting, when compared to 3rds burst-shot shooting, difference averaging 2.8dB, 4.0dB at maximum. In short, the difference is minuscule. Secondly, the sound of the K2 rifle was diminished when shot in a tube, ranging from 2.7dB to 15.4dB, averaging 8.2dB. Thirdly, the shooting sound of the K2 rifle was diminished as the insertion depth deepened with formulas given in Fig. 5, 6. Fourthly, basic data for excluding sound of the shooting were presented. Lastly, the characteristics of the shooting sound could be equally used as a basic material for developing marksmanship and sharp-shooting detection device.

Development and Evaluation Archery Posture Analysis System using Inertial Sensor (관성센서를 이용한 양궁자세 분석 시스템 구축 및 평가)

  • Cho, WooHyeong;Quan, Cheng-Hao;Kwon, Jang-Woo;Lee, Sangmin
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.65 no.10
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    • pp.1746-1754
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    • 2016
  • In this paper, we provide a development and evaluation method for an archery posture analyzing system, using an inertial sensor. The system was developed using LabVIEW2014 by National Instruments and evaluated using the DTW algorithm. To convert the voltage value of the inertial sensor into a physical value, a coordinate transformation matrix bias was applied. To evaluate the similarity of movement in archery shooting, the DTW distance was calculated and similarity was confirmed based on simple mechanical movement, the same person's shooting movement, shooting movement with another person, and the noise signal. The average similarity comparison results were as follows: simple mechanical movement was 17.05%, the same person's shooting movement was 26.48%, shooting movement with another person was 62.8%, and the noise signal was 328.5%; a smaller value indicates a higher level of similarity. We confirmed the possibility of analyzing the archery posture using 3-axis acceleration of the inertial sensor. We inferred that the proposed method might be important means for assessing shooting skills, evaluation of archer's progress, and finding talented archers in advance.

On the subjective response caused by impulse sounds produced by leisure shooting (레저용 사격 소음에 대한 주관적 반응)

  • Kim, Deuk-Sung;Chang, Seo-Il
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.714-720
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    • 2008
  • This research presents a laboratory study about an subjective response of impulsive sound caused by leisure shooting. The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of the jury test adopted a Semantic Difference(SD) Method. In the result of the jury test for impulsive noise, the mean response rating expressed a linear relation and %HA(percent highly annoyed) displayed a exponential growth relation.

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Difference of subjective response between with and without pictures - Focusing on the leisure shooting noise - (화면 제공에 따른 주관적 반응의 차이 - 레저용 사격 소음을 중심으로 -)

  • Kim, Deuk-Sung;Chang, Seo-Il;Lee, Yeon-Soo
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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    • 2008.04a
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    • pp.727-734
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    • 2008
  • This research presents a laboratory study about difference of subjective response between with and without pictures. A main source is impulsive sound caused by leisure shooting. The sources are sampled from outdoor noise and their levels range from 40 to 75 dB at the interval of 5dB. The noise unit is based on A-weighted sound exposure level (ASEL; $L_{AE}$). To make equal ASEL of outdoor noise, finite impulse response (FIR) filter is applied to the originally sampled source to include the effect of distance attenuation. The evaluation method of the jury test adopted a Semantic Difference(SD) Method. The intersection point which two lines crossed was used as reference point. The intersecting point of mean response rating between with and without pictures was approximately 44ASEL and that of %HA was about 60ASEL. In the result of the test, the negative effect of pictures was given at a lower levels than intersection point while the positive effect was given at a higher levels than that.

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