Countermeasure for Reducing Micro-pressure Wave Emitted from Railway Tunnel by Installing Hood at the Exit of Tunnel
|
|
- Corey Quinn
- 5 years ago
- Views:
Transcription
1 PAPER Countermeasure for Reducing Micro-pressure Wave Emitted from Railway Tunnel by Installing Hood at the Exit of Tunnel Sanetoshi SAITO Senior Researcher, Laboratory Head, Tokuzo MIYACHI, Dr. Eng. Assistant Senior Researcher, Heat and Air Flow Analysis Laboratory, Environmental Engineering Division Masanobu IIDA, Dr. Eng. Director, Environmental Engineering Division Micro-pressure waves radiated from tunnel exit portals are one of major wayside environmental problems in high-speed railways, and have thus prompted many studies aimed at developing countermeasures to this phenomenon. This paper proposes a new method involving the addition of a hood to tunnel exit portals to reduce micro-pressure waves. An inside partition divides the inside of the hood in two in the vicinity of the mouth, and one of the partitioned sides is closed off. Confirmation was obtained that the hood is effective in reducing the magnitude of micro-pressure waves. Keywords: micro-pressure wave, pressure wave, railway, tunnel. Introduction Micro-pressure waves are a major wayside environmental problem for high-speed railways and increase greatly with train speed. Consequently, effective measures need to be developed as train running speeds increase. The magnitude of micro-pressure waves is proportional to the maximum pressure gradient of the compression wave arriving at the far end of the tunnel (tunnel exit portal) opposite to the portal through which the train enters [, ]. Micro-pressure waves can, therefore, be reduced by lowering the maximum pressure gradient of the compression wave. Common measures such as tunnel entrance hoods and the optimization of the train nose shape are used to achieve this at a portal through which the train enters (tunnel entrance portal). The compression wave generated at a tunnel entrance portal steepens (i.e. the maximum of its gradient increases) as it propagates through slabtrack tunnels. The larger the maximum of the gradient of the compression wave at the tunnel entrance portal is, by far the larger its increase becomes [3]. Consequently, decreasing this maximum pressure gradient at the tunnel entry portal is very effective for mitigating micro-pressure waves. However, as the speed of today s high speed trains rises, so does the required length of the tunnel entrance hood resulting in some tunnel entrance hoods being over 4 m long. In turn, as tunnel entrance hoods become longer (e.g. over about 4 m for Shinkansen), the effect on reducing micro-pressure waves fall, i.e. there is a ceiling on the effectiveness of this measure [4]. This paper therefore proposes, a new means to reduce micro-pressure waves at tunnel exit portals where radiation of the micro-pressure wave. The exit box, silencer [5], method already achieves this to a certain extent, whereas the method proposed in this paper applies a different approach which improves the measure against micro-pressure waves radiated from the tunnel branch portal which has already proposed in the past [6]. The method involves a hood installed at the tunnel exit portal and with a partition which divides the inside of the hood into two parts in the vicinity of its mouth, and with the end of one part closed. This study predicted the reduction in the micro-pressure wave by acoustic analysis and which was verified by model experiments using a train model launcher.. Investigation of methods for reducing micro-pressure waves. Basic principle As shown in Fig., compression waves are generated by a train entering a tunnel and propagate toward the tunnel exit portal at the speed of sound. When the wave arrives at the tunnel exit portal, a part of its energy is radiated outside in the form of an impulse pressure wave (micro-pressure wave). If the wavefront thickness of the compression wave and the distance of the measured point from the tunnel exit center are much longer than the radius of the tunnel (low-frequency and far-field approximations), the relation between the compression wave p(t) at the exit portal and the micro-pressure wave P(t) is expressed as the following equation [, ]. ρ A u( r / c) A p( r / c) P( t) Ωr where r is air density, A is the cross-sectional area of the tunnel portal, W is the solid angle around the tunnel exit, r is the distance of the measured point from the tunnel center, t is time, c is the speed of sound, and u is the air velocity inside the tunnel at the exit portal. As shown in (), reducing the gradient of the compression wave decreases the micro-pressure wave; in order to attain it, tunnel en- () QR of RTRI, Vol. 54, No. 4, Nov. 3 3
2 Micro-pressure wave Fig. Tunnel Compression wave Train Schematic of the radiation of the micro-pressure wave trance hoods have been installed or train nose shapes have been optimized. On the other hand, reducing the crosssectional area of tunnel portal A also decreases the micropressure wave, as shown in (). However, if the portal cross section is reduced closing part of the opening off with a plate for example, the decrease in the micro-pressure wave is not proportional to the reduction in the cross section, due to the increase in air velocity u [6]. In order to reduce the micro-pressure wave from a side branch of a tunnel, a proposal was made to install a partition to close half the mouth of the tube, as shown in Fig.. The desired effect was then verified through model experiments [6]. However, this measure is impossible to apply in practice because the cross section of the tunnel corresponds closely to the structure gauge; such a partition would prevent the train from passing. This paper therefore proposes an alternative measure, namely for the installation of a hood at the tunnel exit portal whose cross-sectional area is larger than that of the tunnel and is internally divided by a partition (the hood with the inside partition). Cover Fig. Inside partition Compression wave p(t) Schematic illustration of the tube with the inside partition. Prediction of the mitigation effect by acoustic analysis To predict the reduction in the micro-pressure wave in the case of the hood with the inside partition, a set of equations were derived to calculate the micro-pressure wave using the waveform of the compression wave arriving at the tunnel exit portal. The hood with the inside partition is illustrated schematically in Fig.3. It is assumed that the wavefront thickness l w of the compression wave is much larger than the diameter d of the cross section of the tunnel (low-frequency approximation, l w >> d) and that the partition length is much longer than the wavefront thickness (l >> l w ). The wave reflected at the opposite portal (tunnel entrance portal) is not considered, and thickness of the partition plate, the effect of viscosity and the steepening of the wave by non-linear effect during propagation inside the hood are ignored. The compression wave propagated through the tunnel is divided into two waves by the inside partition and the waves propagate through O-side and C-side as plane waves. Each wave is reflected both at the open end and the closed end, and goes back toward point O and point C. There, each reflected wave is divided into two waves. One is reflected back to the end again and the other is transmitted to the opposite end and point J. The wave arriving at (-σ)a h σa h Inside partition L Hood L h C O Tunnel Fig. 3 Schematic illustration of the hood with the inside partition x point J where the cross-sectional area changes discontinuously, is divided between a reflected wave toward the hood and a transmitted wave toward the opposite tunnel portal. As a result, the pressure waves reflected or transmitted at points O and C, and the wave reflected at point J arrive periodically at the open end and the closed end. The pressure inside O-side and C-side at x (L h >x>l h -L) are given by the following equations respectively: { i i } po( x, t) po ( x, t) + po ( x, t) { i i } pc( x, t) pc ( x, t) + pc ( x, t) The reflected waves at the open end po i and at the closed end pc i are given by the following equations, respectively, under low-frequency approximation. L x l po ( h ) i ( x, t) poi c c E J lw p(t) A () (3) (i ) (4) L x pc ( h ) i ( x, t) pci c (i ) (5) where L h is the hood length and l E is the end-correction. Since the end-corrections at points C, O and J, are small, they are ignored. The i-th waves po i and pc i are given by the following equations respectively: ( x Lh poi ( x, t) Ro poi c ( x Lh + Tc pci c x + To RJ poi Tc RJ pci x, t c + ( x Lh pci ( x, t) To poi c ( x Lh + Rc pci c x + To RJ poi Tc RJ pci x, t c + x c x c (i ) (6) (i ) (7) x po ( x, t) pc ( x, t) T J p t (8) where R is the reflection coefficient, T is the transmission coefficient and the subscript of R and T indicate the reflection or transmission point. For example, R o is the reflection coefficient at point O of the wave propagating in the direction of negative x and T -J is the transmission coefficient at point J of the wave propagating in the direction of positive x. For low frequency waves, these values are approximated 3 QR of RTRI, Vol. 54, No. 4, Nov. 3
3 using the following equations which employ the opening ratio s (the ratio of the cross-sectional area of the open end to that of the tunnel, as shown in Fig.3) and the hood crosssectional area ratio s h (A h /A, as shown in Fig.3) [7]. TO s, RO s, TC s, s h RC s, RJ, T J s + s + h When considering the effect of the phase difference by the end-correction at the open end, () is modified as shown in the following [8]. A p p r le P( t) t t rc + W c c h (9) () Therefore, the micro-pressure wave radiated from the hood with the inside partition PO is expressed in the following equation using the pressure wave arriving at the open end po i and the cross-sectional area of the open end sa h. σ poi poi r le PO( t) Lh, Lh, t rc + Ω c c () As shown in (), when the partition length L is long enough, the micro-pressure wave radiated from the hood with the inside partition is decreased to s (opening ratio) times as large as that from the hood without the inside partition (i.e. s. and in ()). On the other hand, using (8), () and (), the ratio of the micro-pressure wave to that from the tunnel exit portal without the hood is ass h /(s h +), which is larger than the opening ratio s. 3. Model scale experiments to verify the mitigation effect 3. Description of the experiment Scaled model experiments using a train model launcher [9] were carried out to verify the effect of reducing the micro-pressure wave by the hood with the inside partition. Table shows the specifications of the models and Fig. 4 is a schematic illustration of the hood. The ground effect is represented by mirror image method []. The model scale is about /. The train model was projected at a speed of V35 km/h or 4 km/h and the opening ratio s of the hood with the inside partition was set at.7 (Fig.4 (b)). As shown in Table, the hood cross-sectional area ratio s h is.36 corresponding to the current standard size of tunnel entrance hoods. The hood length is 9 mm corresponding to 3 m on the real-scale. The cross section of the tunnel model, the hood model and the train model are all circular. A RION NL-3 microphone, located outside at a distance of.4 m from the center of the hood in the lateral direction, was used to measure the micro-pressure wave and three pressure transducers (Kulite XCS-9-5G) were installed inside the tunnel at distance of m from the tunnel exit portal (p), and inside the hood at the center of the inside partition at both the closed side (p) and at the open side (p) (as shown in Fig.4). There were no openings on the side of the hood. Table Model specifications Train Tunnel Hood (unvented) Diameter Length Diameter Length Diameter Length 5 mm mm 5 mm mm 46 mm 9 mm The cross-sectional ratio train to tunnel.7 The cross-sectional ratio hood to tunnel.36 p 95 mm p p (a) Hood without the inside partition 9 mm p L/ L p p (b) Hood with the inside partition Fig. 4 Schematic illustration of hood models QR of RTRI, Vol. 54, No. 4, Nov. 3 33
4 3. Results of the experiment Figure 5 shows the compression wave waveform on arrival at the hood. Although the waveform shown in Fig.5 is measured where L mm, the waveforms in fact to do not rely on hood characteristics (e.g. length, opening ratio, etc.). Therefore, waveforms measured where L5 mm and L5 mm, are the same. As shown in Fig.5, the wavefront thickness l w (defined as the range where the gradient of the compression wave is over 5% of the maximum) is about 65 mm (.9 ms) at a speed of 35 km/h and about 34 mm (. ms) at 4 km/h. Figure 6 shows the micro-pressure wave ratio with respect to the partition length L. The horizontal axis expresses the non-dimensional length based on the wavefront thickness l w at respective speeds. The vertical axis expresses the ratio to the micro-pressure wave radiated from the hood without the partition i.e. the present tunnel entrance hood whose opening ratio is equal to. The nondimensional length expressed as on the horizontal axis is an expression of the present tunnel entrance hood (opening ratio s ) in Fig.6. Fig.6 also shows the result of the calculation using the measured waveform of p at 35 km/ h (Fig.5) in (). Fig.6 further demonstrates that the micropressure wave ratio decreases when L/l w increases and, at L/l w >.5, becomes constant at a value of.7~.75 corresponding to the opening ratio s. Moreover, Fig.6 shows that the result of the calculation by () agrees with that of the experiment. Figure 7 shows the waveforms of the micro-pressure wave where L5 mm (L/l w.3) for a micro-pressure wave ratio constant value of.7~.75 and where L5 mm (L/l w.8) when it is larger than the constant value. In addition, Fig.7 also shows the waveforms predicted by () Pressure (kpa) 4 3 Fig. 5 Micro-pressure wave ratio V35 km/h V4 km/h pressure gradient pressure. ms(34 mm).9 ms(65 mm) Measured waveform of the compression wave on arrival at the hood (p) 4km/h 35km/h calculation (35km/h) σ. without partition Partition length L/l w Fig. 6 Variation of micro-pressure wave in relation to inside partition length Pressure gradient (kpa/s)..4.6 Micro-pressure wave (Pa) Experiment Calculation Pressure (kpa).. - P (Experiment) P (Calculation) 4 3 (a) Partition length L5 m (L/l w.8) P (Experiment) P (Calculation) Micro-pressure wave (Pa) Experiment Calculation.. - (b) Partition length L5 m (L/l w.3) Fig. 7 Waveform of the micro-pressure wave and the pressure wave inside the hood Pressure (kpa) P (Experiment) P (Experiment) P (Calculation) P (Calculation) QR of RTRI, Vol. 54, No. 4, Nov. 3
5 using the measured waveform of p (Fig.5). The waveforms of the micro-pressure wave and those of the pressure inside the hood obtained by experiment and through calculation agreed more or less. This indicates that it is possible to predict the micro-pressure waveform radiated from the hood if the compression waveform on arrival at the hood can be obtained. The hood in the experiments was unvented. Consequently, if a hood is vented, calculated results may at some measurement points disagree with experimental results. The micro-pressure wave is divided into two parts when the micro-pressure wave ratio is at a constant value (Fig.7 (b)), whereas the second part overlaps with the first part when there is no convergence effect (Fig.7 (a)). Although the partition length needs to be longer than l w / to divide the micro-pressure wave completely into two parts, according experimental results a length of between l w /7 to l w /6 would also be effective, i.e. a reduction in the micropressure wave corresponding to the opening ratio can be achieved with a partition length of less than l w / (Fig.6). The reason for this is that so long as the overlap between the first part and second part of the wave does not occur close to their respective peaks, even if their extremities do overlap, it will not affect the maximum of the micro-pressure wave. The optimum partition length to achieve maximum micro-pressure wave mitigation was estimated by on-site measurement in a tunnel of 9.7 km in length []. Since the measured wavefront thickness of the compression wave at the tunnel exit portal was about 6 m, the necessary length was predicted to be half that value i.e. about 3 m. From the above however, it is inferred that the maximum mitigation effect could also be achieved with partition shorter than 3 m, though this would depend on the waveform of the compression wave. 4. Discussions In section, the micro-pressure wave ratio radiated from the hood with the inside partition is considered when it is installed at the exit portal of an actual Shinkansen tunnel. In double-tracked Shinkansen tunnels, trains run in both directions and therefore, in most cases the tunnel entrance hoods are installed at both ends of the tunnel. Therefore, the micro-pressure wave ratio is defined as the ratio of the micro-pressure wave radiated from the hood with the inside partition in relation to that from the hood without the inside partition (i.e. the tunnel entrance hood). Although the micro-pressure wave is obtained by comparing () and (), for simplification, the end-correction is ignore in this chapter. The magnitude of the micropressure wave from the hood without the inside partition is given by the following equation which is derived from (), (8) and (9), ignoring the end-correction. p P( t) t σ h + () where the cross-sectional area of the hood without the inside partition is expressed as A h and its ratio to the tunnel is expressed as s h (A h /A) to distinguish it from hoods with the inside partition. In the same way, the magnitude of the micro-pressure wave from the hood with the inside partition is given by the following equation which is derived from (), ignoring the end-correction. poi PO( t) Lh, (3) PO(t) is the sum of several waves as described in (6)~(8). However, because waves after the third wave (i 3) are multiplied by the second power of reflection or transmission coefficient, they are smaller than the first and the second waves and are therefore negligible. The first and the second waves are given by the following equations which are derived from (6)~(9) and (3). po PO ( t) Lh, p Lh r t σ h + c c po PO ( t) Lh, p rc h ( Lh L r σ ) t Ω σ + c c c R p 3Lh r + ( ) j t c c (4) (5) Comparing the coefficient in (4) and in the first term of (5), shows that the second wave is larger than the first wave when s <.5. However, when s <.5, the crosssectional area of the whole hood with the inside partition A h must be made larger to a certain degree to obtain the cross-sectional area of the opening (sa h ) required for the passage of the train. Moreover, the micro-pressure wave ratio does not lessen in proportion to the opening ratio. Therefore, the feasible opening ratio is probably.5 < s <. In this case, the magnitude of the micro-pressure wave radiated from the hood with the inside partition is defined by the first wave (calculated by (4)). Using () and (4), the micro-pressure wave ratio is given by the following equation: + PO ( t) max s h s (6) P( t) max + s h Equation (6) shows that the micro-pressure wave ratio is defined by the opening ratio s and the cross-sectional area ratio of the hood with the inside partition s h. Figure 8 shows the correlation described in (6) when the crosssectional area ratio of the hood without the inside partition s h is equal to.4 corresponding to the standard value of the tunnel entrance hood installed at actual Shinkansen tunnels. When the cross-sectional area of the hood with the inside partition is equal to that of the hood without the inside partition (s h s h.4), the micro-pressure wave ratio corresponds to the opening ratio. However, when the crosssectional area of the hood with the inside partition is larger than that of the hood without the inside partition (s h >s h ), the micro-pressure wave ratio is larger than the opening ratio (i.e. the mitigation effect on the micro-pressure wave is reduced). The cross-sectional area of the opening (sa h ss h A ) needs to be large to ensure that the train QR of RTRI, Vol. 54, No. 4, Nov. 3 35
6 can pass in order to be able to apply the hood in practice on a Shinkansen line. For example, assuming a standard tunnel entrance hood is remodeled into one with a partition inside it, s h s h.4 is substituted in (7) and therefore, the micro-pressure wave ratio corresponds to the opening ratio, in which case s h.4, and if the cross-sectional area of the opening of the hood with the inside partition corresponds to that of the tunnel (ss h ) which is required to ensure safe passing of a train, s.7. The micro-pressure wave ratio then equals the opening ratio, giving an expected mitigation ratio of about 3%. However, in this case, the cross-sectional area of the entrance for the opposite train, being nearly equal to that of the tunnel, is smaller than that of the hood without the inside partition. Therefore, in order to prevent the effect of the micro-pressure wave generated by the opposite running train, further measures must be taken, such as adding opening windows installed on the hood side surface[,] and having a larger opening cross-sectional area (ss h > ). Ratio of micro-pressure wave. Fig Mitigation effect of the micro-pressure wave by a hood with a inside partition 5. Conclusions Opening ratio σ σ h.4 σ h.7 σ h. A proposal was made for a measure to mitigate micropressure waves, which are a major wayside environmental problem for high-speed railways, at the point of radiation. The effect of this measured was estimated through acoustic analysis and validated by model experiments. The conclusions are as follows: () Micro-pressure waves can be decreased by installing hoods with the inside partition at the tunnel exit portal (point where the train leaves the tunnel and the micro-pressure wave is radiated). The partition serves to divide the inside of the hood into two parts in the vicinity of the hood mouth, forming a type of cul-de-sac on one side of the hood. Its mitigation ratio corresponds to the opening ratio. However, if the hood is vented, the mitigation rate may vary depending on the point being measured. () In order to achieve a reduction in the micro-pressure wave which corresponds to the opening ratio, the length of the inside partition of the hood need only be half the length of the wavefront thickness of the compression wave when it arrives at the tunnel exit portal (e.g. about 3m for Shinkansen tunnel). The maximum reduction could be achieved by a shorter partition though its length depends on the waveform of the compression wave. (3) The waveform of the micro-pressure wave radiated from the hood with the inside partition can be predicted by simple acoustic analysis. References [] Yamamoto, A., Micro-pressure wave radiated from a tunnel exit, Preprint of Physical Society of Japan, 4pH4, pp. 9-96, No.4, Spring, 977 (in Japanese). [] Ozawa, S., Reduction of micro-pressure wave radiated from tunnel exit by hood at tunnel entrance, Quarterly Reports of RTRI, Vol.9, No., 978. [3] Fukuda, T., Ozawa, S., Iida, M., Takasaki, T., Wakabayashi, Y., Distortion of the Compression Wave Propagating Through a Very Long Tunnel with Slab Tracks, Transactions of the Japan Societ of Mechanical Engineers, Vol.7, No.79, pp.48-55, 5 (in Japanese). [4] Ozawa, S., Maeda T., Matsumura T., Uchida K., Kajiyama, H., Tanemoto, K., Countermeasures to Reduce Micro-pressure Waves Radiating from Exits of Shinkansen Tunnels, The 7th Int. Symp. on the Aerodynamics and Ventilation of Vehicle Tunnels, pp.53-66, 99. [5] Aoki, T., Matsuura, T., Matsuo, K., Passive Control of Micro-Pressure Wave from High-Speed Railway Tunnel, Journal of the Visualization Society of Japan, Vol., No., pp.39-3, (in Japanese). [6] Saito, S., Miyachi, T., Iida, M., Reduction of Micropressure Wave Emitted from Portal of Side Branch of High-speed Railway Tunnel, Quarterly Reports of RTRI, Vol.5, No. 3, pp.46-5,. [7] Lighthill, J., Waves in Fluids, Cambridge, UK, p.5, 978. [8] Miyachi, T., A Theoretical Model on Micro-pressure Wave Emission Considering the Effect of Geography around a Tunnel Portal, RTRI Report, Vol. 4, No. 9, pp. 3-8, (in Japanese). [9] Fukuda, T., Iida, M., Model Experiments on Aerodynamics in Train-Tunnel System, Acoustical Science and Technology, Vol.63, No.9, pp , 7 (in Japanese). [] Tanaka, Y., Iida, M., Kikuchi, K., Method to Simulate Generation of Compression Wave Inside a Tunnel at Train Entry with a Simple Geometry Model, Transactions of the Japan Society of Mechanical Engineers, Vol.69, No.683, pp.67-64, 3 (in Japanese). [] Saito, S., Miyachi, T., Iida M., Wakabayashi, Y., Kurita, T., Propagation characteristics of compression wave in a long slab-tracked tunnel, Proceedings () of 7 Meeting of the Japan Society of Mechanical Engineers, pp.67-68, 7 (in Japanese). [] Howe, M., S., The genetically optimized tunnel-entrance hood, J. of Fluids and Structures 3, pp.3-5, QR of RTRI, Vol. 54, No. 4, Nov. 3
Method of Determining Effect of Heat on Mortar by Using Aerial Ultrasonic Waves with Finite Amplitude
Proceedings of 20 th International Congress on Acoustics, ICA 2010 23-27 August 2010, Sydney, Australia Method of Determining Effect of Heat on Mortar by Using Aerial Ultrasonic Waves with Finite Amplitude
More informationEQUIVALENT THROAT TECHNOLOGY
EQUIVALENT THROAT TECHNOLOGY Modern audio frequency reproduction systems use transducers to convert electrical energy to acoustical energy. Systems used for the reinforcement of speech and music are referred
More informationDigital inertial algorithm for recording track geometry on commercial shinkansen trains
Computers in Railways XI 683 Digital inertial algorithm for recording track geometry on commercial shinkansen trains M. Kobayashi, Y. Naganuma, M. Nakagawa & T. Okumura Technology Research and Development
More informationProceedings of Meetings on Acoustics
Proceedings of Meetings on Acoustics Volume 19, 2013 http://acousticalsociety.org/ ICA 2013 Montreal Montreal, Canada 2-7 June 2013 Physical Acoustics Session 4aPA: Nonlinear Acoustics I 4aPA8. Radiation
More informationDESIGN OF VOICE ALARM SYSTEMS FOR TRAFFIC TUNNELS: OPTIMISATION OF SPEECH INTELLIGIBILITY
DESIGN OF VOICE ALARM SYSTEMS FOR TRAFFIC TUNNELS: OPTIMISATION OF SPEECH INTELLIGIBILITY Dr.ir. Evert Start Duran Audio BV, Zaltbommel, The Netherlands The design and optimisation of voice alarm (VA)
More informationUltrasonic Testing using a unipolar pulse
Ultrasonic Testing using a unipolar pulse by Y. Udagawa* and T. Shiraiwa** *Imaging Supersonic Laboratories Co.,Ltd. 12-7 Tezukayamanakamachi Nara Japan 63163 1. Abstract Krautkramer Japan Co.,Ltd. 9-29
More informationModule 2 WAVE PROPAGATION (Lectures 7 to 9)
Module 2 WAVE PROPAGATION (Lectures 7 to 9) Lecture 9 Topics 2.4 WAVES IN A LAYERED BODY 2.4.1 One-dimensional case: material boundary in an infinite rod 2.4.2 Three dimensional case: inclined waves 2.5
More informationSound Source Localization using HRTF database
ICCAS June -, KINTEX, Gyeonggi-Do, Korea Sound Source Localization using HRTF database Sungmok Hwang*, Youngjin Park and Younsik Park * Center for Noise and Vibration Control, Dept. of Mech. Eng., KAIST,
More informationSOUND: A Traffic Simulation Model for Oversaturated Traffic Flow on Urban Expressways
SOUND: A Traffic Simulation Model for Oversaturated Traffic Flow on Urban Expressways Toshio Yoshii 1) and Masao Kuwahara 2) 1: Research Assistant 2: Associate Professor Institute of Industrial Science,
More informationQuantitative Crack Depth Study in Homogeneous Plates Using Simulated Lamb Waves.
More Info at Open Access Database www.ndt.net/?id=18675 Quantitative Crack Depth Study in Homogeneous Plates Using Simulated Lamb Waves. Mohammad. (. SOORGEE, Aghil. YOUSEF)-KOMA Nondestructive Testing
More informationPH213 Chapter 26 solutions
PH213 Chapter 26 solutions 26.6. IDENTIFY: The potential drop is the same across the resistors in parallel, and the current into the parallel combination is the same as the current through the 45.0-Ω resistor.
More informationAcoustic Yagi Uda Antenna Using Resonance Tubes
Acoustic Yagi Uda Antenna Using Resonance Tubes Yuki TAMURA 1 ; Kohei YATABE 2 ; Yasuhiro OUCHI 3 ; Yasuhiro OIKAWA 4 ; Yoshio YAMASAKI 5 1 5 Waseda University, Japan ABSTRACT A Yagi Uda antenna gets high
More informationFumiaki UEHAN, Dr.. Eng. Senior Researcher, Structural Mechanics Laboratory, Railway Dynamics Div.
PAPER Development of the Non-contact Vibration Measuring System for Diagnosis of Railway Structures Fumiaki UEHAN, Dr.. Eng. Senior Researcher, Structural Mechanics Laboratory, Railway Dynamics Div. This
More informationSound absorption and reflection with coupled tubes
Sound absorption and reflection with coupled tubes Abstract Frits van der Eerden University of Twente, Department of Mechanical Engineering (WB-TMK) P.O. Box 27, 75 AE Enschede, The Netherlands f.j.m.vandereerden@wb.utwente.nl
More informationUltrasonic Guided Wave Testing of Cylindrical Bars
18th World Conference on Nondestructive Testing, 16-2 April 212, Durban, South Africa Ultrasonic Guided Wave Testing of Cylindrical Bars Masanari Shoji, Takashi Sawada NTT Energy and Environment Systems
More informationCorona Current-Voltage Characteristics in Wire-Duct Electrostatic Precipitators Theory versus Experiment
Ziedan et al. 154 Corona Current-Voltage Characteristics in Wire-Duct Electrostatic Precipitators Theory versus Experiment H. Ziedan 1, J. Tlustý 2, A. Mizuno 3, A. Sayed 1, and A. Ahmed 1 1 Department
More informationLocalizing Noise Sources on a Rail Vehicle during Pass-by
Localizing Noise Sources on a Rail Vehicle during Pass-by J. Gomes 1, J. Hald 1 and B. Ginn 1 1 Brüel & Kjaer Sound & Vibration Measurement A/S, Skodsborgvej 307, DK-2850 Naerum, Denmark E-mail: Jesper.Gomes@bksv.com
More informationApplication Note 106 IP2 Measurements of Wideband Amplifiers v1.0
Application Note 06 v.0 Description Application Note 06 describes the theory and method used by to characterize the second order intercept point (IP 2 ) of its wideband amplifiers. offers a large selection
More informationInvestigation of Noise Spectrum Characteristics for an Evaluation of Railway Noise Barriers
IJR International Journal of Railway Vol. 6, No. 3 / September 2013, pp. 125-130 ISSN 1976-9067(Print) ISSN 2288-3010(Online) Investigation of Noise Spectrum Characteristics for an Evaluation of Railway
More informationPanPhonics Panels in Active Control of Sound
PanPhonics White Paper PanPhonics Panels in Active Control of Sound Seppo Uosukainen VTT Building and Transport Contents Introduction... 1 Active control of sound... 1 Interference... 2 Control system...
More informationImplementation of decentralized active control of power transformer noise
Implementation of decentralized active control of power transformer noise P. Micheau, E. Leboucher, A. Berry G.A.U.S., Université de Sherbrooke, 25 boulevard de l Université,J1K 2R1, Québec, Canada Philippe.micheau@gme.usherb.ca
More information1. Introduction. 2. Concept. reflector. transduce r. node. Kraftmessung an verschiedenen Fluiden in akustischen Feldern
1. Introduction The aim of this Praktikum is to familiarize with the concept and the equipment of acoustic levitation and to measure the forces exerted by an acoustic field on small spherical objects.
More informationDetection of Protective Coating Disbonds in Pipe Using Circumferential Guided Waves
17th World Conference on Nondestructive Testing, 25-28 Oct 2008, Shanghai, China Detection of Protective Coating Disbonds in Pipe Using Circumferential Guided Waves Jason K. Van Velsor Pennsylvania State
More informationSelective Excitation of Lamb Wave Modes in Thin Aluminium Plates using Bonded Piezoceramics: Fem Modelling and Measurements
ECNDT 6 - Poster 5 Selective Excitation of Lamb Wave Modes in Thin Aluminium Plates using Bonded Piezoceramics: Fem Modelling and Measurements Yago GÓMEZ-ULLATE, Francisco MONTERO DE ESPINOSA, Instituto
More informationMethods for Reducing Leakage Electric Field of a Wireless Power Transfer System for Electric Vehicles
Methods for Reducing Leakage Electric Field of a Wireless Power Transfer System for Electric Vehicles Masaki Jo, Yukiya Sato, Yasuyoshi Kaneko, Shigeru Abe Graduate School of Science and Engineering Saitama
More informationENHANCEMENT OF THE TRANSMISSION LOSS OF DOUBLE PANELS BY MEANS OF ACTIVELY CONTROLLING THE CAVITY SOUND FIELD
ENHANCEMENT OF THE TRANSMISSION LOSS OF DOUBLE PANELS BY MEANS OF ACTIVELY CONTROLLING THE CAVITY SOUND FIELD André Jakob, Michael Möser Technische Universität Berlin, Institut für Technische Akustik,
More informationHIGH FREQUENCY INTENSITY FLUCTUATIONS
Proceedings of the Seventh European Conference on Underwater Acoustics, ECUA 004 Delft, The Netherlands 5-8 July, 004 HIGH FREQUENCY INTENSITY FLUCTUATIONS S.D. Lutz, D.L. Bradley, and R.L. Culver Steven
More informationTHE PROPAGATION OF PARTIAL DISCHARGE PULSES IN A HIGH VOLTAGE CABLE
THE PROPAGATION OF PARTIAL DISCHARGE PULSES IN A HIGH VOLTAGE CABLE Z.Liu, B.T.Phung, T.R.Blackburn and R.E.James School of Electrical Engineering and Telecommuniications University of New South Wales
More informationUse of trig to find the vertical Or horizontal component of the initial velocity
1(a)(i) Use of trig to find the vertical Or horizontal component of the initial velocity Use of suitable equations of motion to calculate total time of flight of the ball Use of v = s/t Total horizontal
More informationNON CONTACT VIBRATION MEASUREMENTS ON PARABOLIC SURFACE ANTENNA. Dorin Simoiu 1, Liviu Bereteu 1
Analele Universităţii de Vest din Timişoara Vol. LVII, 2013 Seria Fizică NON CONTACT VIBRATION MEASUREMENTS ON PARABOLIC SURFACE ANTENNA Dorin Simoiu 1, Liviu Bereteu 1 1 Mechanical and Vibration Department,
More informationAbout Doppler-Fizeau effect on radiated noise from a rotating source in cavitation tunnel
PROCEEDINGS of the 22 nd International Congress on Acoustics Signal Processing in Acoustics (others): Paper ICA2016-111 About Doppler-Fizeau effect on radiated noise from a rotating source in cavitation
More informationVisualization of the Ionization Phenomenon in Porous Materials under Lightning Impulse
Visualization of the Ionization Phenomenon in Porous Materials under Lightning Impulse A. Elzowawi, A. Haddad, H. Griffiths Abstract the electric discharge and soil ionization phenomena have a great effect
More informationTyre Cavity Coupling Resonance and Countermeasures Zamri Mohamed 1,a, Laith Egab 2,b and Xu Wang 2,c
Tyre Cavity Coupling Resonance and Countermeasures Zamri Mohamed 1,a, Laith Egab,b and Xu Wang,c 1 Fakulti Kej. Mekanikal, Univ. Malaysia Pahang, Malaysia 1, School of Aerospace, Mechanical and Manufacturing
More informationThe spatial structure of an acoustic wave propagating through a layer with high sound speed gradient
The spatial structure of an acoustic wave propagating through a layer with high sound speed gradient Alex ZINOVIEV 1 ; David W. BARTEL 2 1,2 Defence Science and Technology Organisation, Australia ABSTRACT
More informationinter.noise 2000 The 29th International Congress and Exhibition on Noise Control Engineering August 2000, Nice, FRANCE
Copyright SFA - InterNoise 2000 1 inter.noise 2000 The 29th International Congress and Exhibition on Noise Control Engineering 27-30 August 2000, Nice, FRANCE I-INCE Classification: 7.2 MICROPHONE T-ARRAY
More informationNS blade / ADVANCED AIR KNIFE FOR HOT DIP CONTINUOUS GALVANIZING LINE YUTA SUMITOMO* HATSUKI KAKUNO*
NS blade / ADVANCED AIR KNIFE FOR HOT DIP CONTINUOUS GALVANIZING LINE BY YUTA SUMITOMO* HATSUKI KAKUNO* SYNOPSIS: Nippon Steel& Sumikin Engineering (hereinafter referred to as NSENGI ) and its subsidiary
More informationAcoustic Based Angle-Of-Arrival Estimation in the Presence of Interference
Acoustic Based Angle-Of-Arrival Estimation in the Presence of Interference Abstract Before radar systems gained widespread use, passive sound-detection based systems were employed in Great Britain to detect
More informationAnalysis of Collided Signal Waveform on the Long Transmission Line of UART-CSMA/CD Control Network
PIERS ONLINE, VOL. 5, NO. 2, 2009 171 Analysis of Collided Signal Waveform on the Long Transmission Line of UART-CSMA/CD Control Network Chuzo Ninagawa 1 and Yasumitsu Miyazaki 2 1 Mitsubishi Heavy Industries,
More informationMulti Level Temperature Measurement Using a single 90 bend waveguide
More info about this article: http://www.ndt.net/?id=21199 Multi Level Temperature Measurement Using a single 90 bend waveguide Nishanth R 1a, Lingadurai K 1, Suresh Periyannan a and Krishnan Balasubramaniam
More informationEquivalent Circuits for Repeater Antennas Used in Wireless Power Transfer via Magnetic Resonance Coupling
Electrical Engineering in Japan, Vol. 183, No. 1, 2013 Translated from Denki Gakkai Ronbunshi, Vol. 131-D, No. 12, December 2011, pp. 1373 1382 Equivalent Circuits for Repeater Antennas Used in Wireless
More informationValidation of the Experimental Setup for the Determination of Transmission Loss of Known Reactive Muffler Model by Using Finite Element Method
Validation of the Experimental Setup for the etermination of Transmission Loss of Known Reactive Muffler Model by Using Finite Element Method M.B. Jadhav, A. P. Bhattu Abstract: The expansion chamber is
More informationDevelopment of the air-coupled ultrasonic vertical reflection method
15 th Asia Pacific Conference for Non-Destructive Testing (APCNDT217), Singapore. Development of the air-coupled ultrasonic vertical reflection method M. Endo, M. Ishikawa 1, H. Nishino 1 and S.Sugimoto
More informationUIC PHYSICS 105 Fall 2014 Final Exam
UIC: Physics 105 Final Exam Fall 2014 Wednesday, December 10 # LAST Name (print) FIRST Name (print) Signature: UIN #: Giving or receiving aid in any examination is cause for dismissal from the University.
More informationTRAIN INDUCED SEISMIC NOISE OF ACCELERATING AND DECELERATING TRAIN SETS
TRAIN INDUCED SEISMIC NOISE OF ACCELERATING AND DECELERATING TRAIN SETS ABSTRACT: M. Çetin 1, A. Tongut 2, S.Ü. Dikmen 3 and Ali Pınar 4 1 Civil Eng., Dept. of Earthquake Engineering, KOERI, Bogazici University,
More informationVisualization of Shock Waves by using Schlieren Technique
Lab # 3 Visualization of Shock Waves by using Schlieren Technique Objectives: 1. To get hands-on experiences about Schlieren technique for flow visualization. 2. To learn how to do the optics alignment
More informationSIGNAL PROCESSING ALGORITHMS FOR HIGH-PRECISION NAVIGATION AND GUIDANCE FOR UNDERWATER AUTONOMOUS SENSING SYSTEMS
SIGNAL PROCESSING ALGORITHMS FOR HIGH-PRECISION NAVIGATION AND GUIDANCE FOR UNDERWATER AUTONOMOUS SENSING SYSTEMS Daniel Doonan, Chris Utley, and Hua Lee Imaging Systems Laboratory Department of Electrical
More informationACCURACY IMPROVEMENT ON NON-INVASIVE ULTRASONIC-DOPPLER FLOW MEASUREMENT BY UTILZING SHEAR WAVES IN METAL PIPE
4th International Symposium on Ultrasonic Doppler Method for Fluid Mechanics and Fluid Engineering Sapporo, 6.-8. September, 24 ACCURACY IMPROVEMENT ON NON-INVASIVE ULTRASONIC-DOPPLER FLOW MEASUREMENT
More informationEstimation of the Loss in the ECH Transmission Lines for ITER
Estimation of the Loss in the ECH Transmission Lines for ITER S. T. Han, M. A. Shapiro, J. R. Sirigiri, D. Tax, R. J. Temkin and P. P. Woskov MIT Plasma Science and Fusion Center, MIT Building NW16-186,
More informationMicrophone Array Measurements for High-speed Train
Microphone Array Measurements for High-speed Train Korea Research Institute of Standards and Science Hyu-Sang Kwon 2016. 05. 31 2 Contents Railway Noise Sound Images Flow Noise Railway Noise Measurement
More informationImplementation of electromagnetic acoustic resonance in pipe inspection
E-Journal of Advanced Maintenance Vol.5-1(2013) 25-33 Implementation of electromagnetic acoustic resonance in pipe inspection Ryoichi URAYAMA 1 Toshiyuki TAKAGI 1,*, Tetsuya UCHIMOTO 1, Shigeru KANEMOTO
More informationA High-Bandwidth Electrical-Waveform Generator Based on Aperture-Coupled Striplines for OMEGA Pulse-Shaping Applications
A High-Bandwidth Electrical-Waveform Generator Based on Aperture-Coupled Striplines for OMEGA Pulse-Shaping Applications Pulsed-laser systems emit optical pulses having a temporal pulse shape characteristic
More informationFOREBODY VORTEX CONTROL ON HIGH PERFORMANCE AIRCRAFT USING PWM- CONTROLLED PLASMA ACTUATORS
26 TH INTERNATIONAL CONGRESS OF THE AERONAUTICAL SCIENCES FOREBODY VORTEX CONTROL ON HIGH PERFORMANCE AIRCRAFT USING PWM- CONTROLLED PLASMA ACTUATORS Takashi Matsuno*, Hiromitsu Kawazoe*, Robert C. Nelson**,
More informationDevelopment of a Reactive Silencer for Turbo Compressors
Development of a Reactive Silencer for Turbo Compressors Jan Smeulers Nestor Gonzalez TNO Fluid Dynamics TNO Fluid Dynamics Stieltjesweg 1 Stieltjesweg 1 2628CK Delft 2628CK Delft jan.smeulers@tno.nl nestor.gonzalezdiez@tno.nl
More informationDevelopment of Distributed-type Linear Generator with Damping Control. Toshiaki MURAI Chief Researcher,
PAPER Development of Distributed-type Linear Generator with Damping Control Takamitsu YAMAMOTO Researcher, Toshiaki MURAI Chief Researcher, Hitoshi HASEGAWA Researcher, Maglev Technology Div.,Maglev Development
More informationRevised zone method R-value calculation for precast concrete. sandwich panels containing metal wythe connectors. Byoung-Jun Lee and Stephen Pessiki
Revised zone method R calculation for precast concrete sandwich panels containing metal wythe connectors Byoung-Jun Lee and Stephen Pessiki Editor s quick points n Metal wythe connectors are used in a
More informationCompact MIMO Antenna with Cross Polarized Configuration
Proceedings of the 4th WSEAS Int. Conference on Electromagnetics, Wireless and Optical Communications, Venice, Italy, November 2-22, 26 11 Compact MIMO Antenna with Cross Polarized Configuration Wannipa
More informationA mobile reverberation cabin for acoustic measurements in an existing anechoic room
A mobile reverberation cabin for acoustic measurements in an existing anechoic room Elsa PIOLLET 1 ; Simon LAROCHE 2 ; Marc-Antoine BIANKI 3 ; Annie ROSS 4 1,2,3,4 Ecole Polytechnique de Montreal, Canada
More informationWind Loading On Base Station Antennas
Wind Loading On Base Station ntennas By Matt Ferris, Principal Mechanical Engineer June 009 Introduction s wireless telecommunication services continue to expand, wireless providers are deploying more
More informationMethod to Evaluate the Appropriateness of Introducing a High Speed Data Transmission System Using Metallic Telecommunication Lines onto Railways
PAPER Method to Evaluate the Appropriateness of Introducing a High Speed Data System Using Metallic Telecommunication Lines onto Railways Keiichi TAKEUCHI Assistant Senior Researcher, Kazuki NAKAMURA Senior
More informationA White Paper on Danley Sound Labs Tapped Horn and Synergy Horn Technologies
Tapped Horn (patent pending) Horns have been used for decades in sound reinforcement to increase the loading on the loudspeaker driver. This is done to increase the power transfer from the driver to the
More informationThe Development of Laser Ultrasonic Visualization Equipment and its Application in Nondestructive Inspection
17th World Conference on Nondestructive Testing, 25-28 Oct 2008, Shanghai, China The Development of Laser Ultrasonic Visualization Equipment and its Application in Nondestructive Inspection Bo WANG 1,
More informationConsiderations about Radiated Emission Tests in Anechoic Chambers that do not fulfil the NSA Requirements
6 th IMEKO TC Symposium Sept. -, 8, Florence, Italy Considerations about Radiated Emission Tests in Anechoic Chambers that do not fulfil the NSA Requirements M. Borsero, A. Dalla Chiara 3, C. Pravato,
More informationRayleigh Wave Interaction and Mode Conversion in a Delamination
Rayleigh Wave Interaction and Mode Conversion in a Delamination Sunil Kishore Chakrapani a, Vinay Dayal, a and Jamie Dunt b a Department of Aerospace Engineering & Center for NDE, Iowa State University,
More informationINTERNAL CONCRETE INSPECTION AND EVALUATION METHODS FOR STEEL PLATE-BONDED SLABS BY USING ELASTIC WAVES VIA ANCHOR BOLTS
More info about this article: h Czech Society for Nondestructive Testing 32 nd European Conference on Acoustic Emission Testing Prague, Czech Republic, September 7-9, 216 INTERNAL CONCRETE INSPECTION AND
More informationOn the accuracy reciprocal and direct vibro-acoustic transfer-function measurements on vehicles for lower and medium frequencies
On the accuracy reciprocal and direct vibro-acoustic transfer-function measurements on vehicles for lower and medium frequencies C. Coster, D. Nagahata, P.J.G. van der Linden LMS International nv, Engineering
More informationImpact sound insulation: Transient power input from the rubber ball on locally reacting mass-spring systems
Impact sound insulation: Transient power input from the rubber ball on locally reacting mass-spring systems Susumu HIRAKAWA 1 ; Carl HOPKINS 2 ; Pyoung Jik LEE 3 Acoustics Research Unit, School of Architecture,
More informationLasers PH 645/ OSE 645/ EE 613 Summer 2010 Section 1: T/Th 2:45-4:45 PM Engineering Building 240
Lasers PH 645/ OSE 645/ EE 613 Summer 2010 Section 1: T/Th 2:45-4:45 PM Engineering Building 240 John D. Williams, Ph.D. Department of Electrical and Computer Engineering 406 Optics Building - UAHuntsville,
More informationProgressive Transition TM (PT) Waveguides
Technical Notes Volume, Number 3 Progressive Transition TM (PT) Waveguides Background: The modern constant-directivity horn has evolved slowly since its introduction over 25 years ago. Advances in horn
More informationThe Next Linear Collider Test Accelerator s RF Pulse Compression and Transmission Systems
SLAC-PUB-7247 February 1999 The Next Linear Collider Test Accelerator s RF Pulse Compression and Transmission Systems S. G. Tantawi et al. Presented at the 5th European Particle Accelerator Conference
More informationA Numerical Study of Depth of Penetration of Eddy Currents
A Numerical Study of Depth of Penetration of Eddy Currents S.Majidnia* a,b, R.Nilavalan b, J. Rudlin a a. TWI Ltd, Cambridge,United Kingdom b Brunel University, London,United Kingdom shiva.majidnia@twi.co.uk
More informationA minimum hydrophone bandwidth for undistorted cavitation noise measurement
13. 15. května 2008 A minimum hydrophone bandwidth for undistorted cavitation noise measurement Karel Vokurka a, Silvano Buogo b a Physics Department, Technical University of Liberec, Studentská 2, 461
More informationSmartSenseCom Introduces Next Generation Seismic Sensor Systems
SmartSenseCom Introduces Next Generation Seismic Sensor Systems Summary: SmartSenseCom, Inc. (SSC) has introduced the next generation in seismic sensing technology. SSC s systems use a unique optical sensing
More informationPresented at the 109th Convention 2000 September Los Angeles, California, USA
Development of a Piezo-Electric Super Tweeter Suitable for DVD-Audio 5 Mitsukazu Kuze and Kazue Satoh Multimedia Development Center Matsushita Electric Industrial Co., Ltd. Kadoma-city, Osaka 57 l-8, Japan
More informationSteam Generator Tubing Inspection
6th International Conference on NDE in Relation to Structural Integrity for Nuclear and Pressurized Components October 27, Budapest, Hungary For more papers of this publication click: www.ndt.net/search/docs.php3?mainsource=7
More informationA Method for Estimating Noise from Full-Scale Distributed Exhaust Nozzles
A Method for Estimating Noise from Full-Scale Distributed Exhaust Nozzles Kevin W. Kinzie * NASA Langley Research Center, Hampton, VA 23681 David. B. Schein Northrop Grumman Integrated Systems, El Segundo,
More informationLINEAR INDUCTION ACCELERATOR WITH MAGNETIC STEERING FOR INERTIAL FUSION TARGET INJECTION
LINEAR INDUCTION ACCELERATOR WITH MAGNETIC STEERING FOR INERTIAL FUSION TARGET INJECTION Ronald Petzoldt,* Neil Alexander, Lane Carlson, Eric Cotner, Dan Goodin and Robert Kratz General Atomics, 3550 General
More informationULTRASONIC GUIDED WAVE ANNULAR ARRAY TRANSDUCERS FOR STRUCTURAL HEALTH MONITORING
ULTRASONIC GUIDED WAVE ANNULAR ARRAY TRANSDUCERS FOR STRUCTURAL HEALTH MONITORING H. Gao, M. J. Guers, J.L. Rose, G. (Xiaoliang) Zhao 2, and C. Kwan 2 Department of Engineering Science and Mechanics, The
More informationIT Series Woofers and Compression Drivers
IT Series Woofers and Compression Drivers Enclosure and Crossover Applications The HC Design IT Series low frequency woofers and high frequency drivers are very high performance transducers designed for
More informationHigh contrast air-coupled acoustic imaging with zero group velocity Lamb modes
Aerospace Engineering Conference Papers, Presentations and Posters Aerospace Engineering 7-3 High contrast air-coupled acoustic imaging with zero group velocity Lamb modes Stephen D. Holland Iowa State
More informationProceedings of Meetings on Acoustics
Proceedings of Meetings on Acoustics Volume 19, 2013 http://acousticalsociety.org/ ICA 2013 Montreal Montreal, Canada 2-7 June 2013 Physical Acoustics Session 2pPA: Material Characterization 2pPA9. Experimental
More informationTELEMETERING VIA LEAKY WAVEGUIDES
TELEMETERING VIA LEAKY WAVEGUIDES Item Type text; Proceedings Authors Hu, A. S. Publisher International Foundation for Telemetering Journal International Telemetering Conference Proceedings Rights Copyright
More informationAN electromagnetic launcher system can accelerate a projectile
4434 IEEE TRANSACTIONS ON MAGNETICS, VOL. 33, NO. 6, NOVEMBER 1997 Hyper Velocity Acceleration by a Pulsed Coilgun Using Traveling Magnetic Field Katsumi Masugata, Member, IEEE Abstract A method is proposed
More informationINFLUENCE OF THE PERFOMANCE PARAMETERS IN TRANSMISSION LINE LOUDSPEAKER SYSTEM
INFLUENCE OF THE PERFOMANCE PARAMETERS IN TRANSMISSION LINE LOUDSPEAKER SYSTEM PACS number: 43.38.Ja Basilio Pueo, José Escolano, and Miguel Romá Department of Physics, System Engineering and Signal Theory,
More informationPREDICTION OF RAILWAY INDUCED GROUND VIBRATION
inter.noise 2000 The 29th International Congress and Exhibition on Noise Control Engineering 27-30 August 2000, Nice, FRANCE Paper IN2000/467 http://confs.loa.espci.fr/in2000/000467/000467.pdf PREDICTION
More informationInterior Noise Characteristics in Japanese, Korean and Chinese Subways
IJR International Journal of Railway Vol. 6, No. 3 / September, pp. 1-124 The Korean Society for Railway Interior Noise Characteristics in Japanese, Korean and Chinese Subways Yoshiharu Soeta, Ryota Shimokura*,
More informationImpact of Mobility and Closed-Loop Power Control to Received Signal Statistics in Rayleigh Fading Channels
mpact of Mobility and Closed-Loop Power Control to Received Signal Statistics in Rayleigh Fading Channels Pekka Pirinen University of Oulu Telecommunication Laboratory and Centre for Wireless Communications
More informationOblique incidence measurement setup for millimeter wave EM absorbers
Oblique incidence measurement setup for millimeter wave EM absorbers Shinichiro Yamamoto a) and Kenichi Hatakeyama Graduate School of Engineering, University of Hyogo, 2167 Shosha, Himeji-shi, Hyogo 671
More informationProceedings of Meetings on Acoustics
Proceedings of Meetings on Acoustics Volume 19, 2013 http://acousticalsociety.org/ ICA 2013 Montreal Montreal, Canada 2-7 June 2013 Engineering Acoustics Session 1pEAb: Transduction, Transducers, and Energy
More informationAnalysis of Laddering Wave in Double Layer Serpentine Delay Line
International Journal of Applied Science and Engineering 2008. 6, 1: 47-52 Analysis of Laddering Wave in Double Layer Serpentine Delay Line Fang-Lin Chao * Chaoyang University of Technology Taichung, Taiwan
More informationTransmission Line Transient Overvoltages (Travelling Waves on Power Systems)
Transmission Line Transient Overvoltages (Travelling Waves on Power Systems) The establishment of a potential difference between the conductors of an overhead transmission line is accompanied by the production
More informationDAMAGE EVALUATION BY FREQUENCY ANALYSIS OF CONTINU- OUS RECORDED AE WAVEFORM
DAMAGE EVALUATION BY FREQUENCY ANALYSIS OF CONTINU- OUS RECORDED AE WAVEFORM KAITA ITO and MANABU ENOKI Department of Materials Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656,
More informationCHAPTER 4 COMPARISON OF DYNAMIC ELASTIC BEHAVIOUR OF COTTON AND COTTON / SPANDEX KNITTED FABRICS
31 CHAPTER 4 COMPARISON OF DYNAMIC ELASTIC BEHAVIOUR OF COTTON AND COTTON / SPANDEX KNITTED FABRICS 4.1 INTRODUCTION Elastic garments for sports and outer wear play an important role in optimizing an athletic
More informationHUYGENS PRINCIPLE AND INTERFERENCE
HUYGENS PRINCIPLE AND INTERFERENCE VERY SHORT ANSWER QUESTIONS Q-1. Can we perform Double slit experiment with ultraviolet light? Q-2. If no particular colour of light or wavelength is specified, then
More informationMagnetism and Induction
Magnetism and Induction Before the Lab Read the following sections of Giancoli to prepare for this lab: 27-2: Electric Currents Produce Magnetism 28-6: Biot-Savart Law EXAMPLE 28-10: Current Loop 29-1:
More informationLaser Beam Analysis Using Image Processing
Journal of Computer Science 2 (): 09-3, 2006 ISSN 549-3636 Science Publications, 2006 Laser Beam Analysis Using Image Processing Yas A. Alsultanny Computer Science Department, Amman Arab University for
More informationThe vibration transmission loss at junctions including a column
The vibration transmission loss at junctions including a column C. Crispin, B. Ingelaere, M. Van Damme, D. Wuyts and M. Blasco Belgian Building Research Institute, Lozenberg, 7, B-19 Sint-Stevens-Woluwe,
More informationEXPERIMENTS ON PERFORMANCES OF ACTIVE-PASSIVE HYBRID MUFFLERS
EXPERIMENTS ON PERFORMANCES OF ACTIVE-PASSIVE HYBRID MUFFLERS Hongling Sun, Fengyan An, Ming Wu and Jun Yang Key Laboratory of Noise and Vibration Research, Institute of Acoustics, Chinese Academy of Sciences,
More informationPRODUCT DATA. Sound Intensity Calibrator Type 4297
PRODUCT DATA Sound Intensity Calibrator Type 4297 Sound Intensity Calibrator Type 4297 is used for on-site sound-pressure calibration and pressure-residual intensity-index verification. Its most important
More informationTHE PATTERNS OF THE SOUND INTENSITY DISTRIBUTION OF MIDRANGE LOUDSPEAKER
Proceeding of International Conference On Research, Implementation And Education Of Mathematics And Sciences 2014, Yogyakarta State University, 18-20 May 2014 THE PATTERNS OF THE SOUND INTENSITY DISTRIBUTION
More information4 Investigation of EMC in Wireless Communication Systems
4 Investigation of EMC in Wireless Communication Systems 4-1 Electromagnetic Disturbance Measurement by Using Amplitude Probability Distribution for Protecting Digital Wireless Communication Systems GOTOH
More information