International Journal of Vehicle Noise and Vibration http://www.inderscience.com/browse/index.php?journalID=52&year=2011&vol=7&issue=4 Inderscience Publishers Ltd en-uk International Journal of Vehicle Noise and Vibration 1479-1471 1479-148X © 2011 Inderscience Publishers Ltd editor@inderscience.com https://www.inderscience.com/images/files/coverImgs/ijvnv_scoverijvnv.gif http://www.inderscience.com/browse/index.php?journalID=52&year=2011&vol=7&issue=4 http://www.inderscience.com/link.php?id=43191 The effect of flow on the acoustic characteristics of a Helmholtz resonator is investigated experimentally. An impedance tube set-up has been modified to facilitate the measurement of transmission loss in the presence of mean flow. Acoustic impedance of the resonator is also measured with and without flow, enabling the analysis of this parameter as well. Transmission loss directly measured from the improved impedance tube set-up is then compared with that calculated from the acoustic impedance. The results demonstrate that the flow effect on Helmholtz resonators is dramatic in terms of the resonance frequency and peak magnitude by shifting the peak transmission loss frequency to higher values and deteriorating the peak transmission loss magnitude (18.3% increase and 31 dB decrease, respectively, for Mach number, Ma = 0.1). Acoustic performance of a Helmholtz resonator with flow
Hyunsu Kim; Ahmet Selamet
International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 285 - 305
The effect of flow on the acoustic characteristics of a Helmholtz resonator is investigated experimentally. An impedance tube set-up has been modified to facilitate the measurement of transmission loss in the presence of mean flow. Acoustic impedance of the resonator is also measured with and without flow, enabling the analysis of this parameter as well. Transmission loss directly measured from the improved impedance tube set-up is then compared with that calculated from the acoustic impedance. The results demonstrate that the flow effect on Helmholtz resonators is dramatic in terms of the resonance frequency and peak magnitude by shifting the peak transmission loss frequency to higher values and deteriorating the peak transmission loss magnitude (18.3% increase and 31 dB decrease, respectively, for Mach number, Ma = 0.1).

]]> 10.1504/IJVNV.2011.043191 International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 285 - 305 Hyunsu Kim; Ahmet Selamet Department of Mechanical Engineering and The Center for Automotive Research, The Ohio State University, Columbus, OH 43210-1107, USA. ' Department of Mechanical Engineering and The Center for Automotive Research, The Ohio State University, Columbus, OH 43210-1107, USA Helmholtz resonator flow effect transmission loss acoustics vehicle noise acoustic impedance. 2011-10-19T23:20:50-05:00 7 4 285 305 2011-10-19T23:20:50-05:00 http://www.inderscience.com/link.php?id=43192 Exact solutions for free vibration and static deflection of cross-ply laminated cylindrical panels and circular cylindrical shells are obtained using deep first order shell theory. The state space approach has been used to generate the exact solutions for different sets of boundary conditions. Comparison between the results has been made using the deep first order shell theory and the less accurate one, where the 1 + z / R terms have been approximated by unity. The effects of various parameters including shear deformation, shallowness of the shell, orthotropicity ratio, lamination scheme and boundary condition on shell frequencies and centre deflections are studied. The fundamental frequencies of the deep shell theory are compared with 3D theory of elasticity available in the literature. Comparative dynamic and static studies for cross-ply shells based on a deep thick shell theory
Ahmed Adel Khdeir
International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 306 - 327
Exact solutions for free vibration and static deflection of cross-ply laminated cylindrical panels and circular cylindrical shells are obtained using deep first order shell theory. The state space approach has been used to generate the exact solutions for different sets of boundary conditions. Comparison between the results has been made using the deep first order shell theory and the less accurate one, where the 1 + z / R terms have been approximated by unity. The effects of various parameters including shear deformation, shallowness of the shell, orthotropicity ratio, lamination scheme and boundary condition on shell frequencies and centre deflections are studied. The fundamental frequencies of the deep shell theory are compared with 3D theory of elasticity available in the literature.

]]> 10.1504/IJVNV.2011.043192 International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 306 - 327 Ahmed Adel Khdeir Mechanical Engineering Department, King Saud University, P.O. Box 800, Riyadh 11421, Kingdom of Saudi Arabia laminated composite shells deep thick shells cross-ply shells free vibration static deflection exact solutions vehicle vibration automotive structures laminated cylindrical panels circular cylindrical shells. 2011-10-19T23:20:50-05:00 7 4 306 327 2011-10-19T23:20:50-05:00 http://www.inderscience.com/link.php?id=43193 The purpose of this investigation is to quantify the loss of speech intelligibility related to communication between passengers inside a vehicle at different vehicle operating conditions and road surfaces using common objective speech intelligibility metrics. The goal was to identify the most appropriate metric, if a single one exists, for use in automotive applications. The objective metrics include the articulation index (AI), the speech intelligibility index (SII) and the speech transmission index (STI). The SII method, utilising user-defined, measured, speech signal was found to be the best out of the three metrics for quantifying in-vehicle speech intelligibility. Since the effect of reverberation on the loss of speech intelligibility was negligible, this method resulted in a close correlation with the more measurement-intensive STI method. This potentially provides a reduction in measurement effort while preserving the accuracy of the results. In-vehicle application of common speech intelligibility metrics
Nikolina Samardzic; Colin Novak
International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 328 - 346
The purpose of this investigation is to quantify the loss of speech intelligibility related to communication between passengers inside a vehicle at different vehicle operating conditions and road surfaces using common objective speech intelligibility metrics. The goal was to identify the most appropriate metric, if a single one exists, for use in automotive applications. The objective metrics include the articulation index (AI), the speech intelligibility index (SII) and the speech transmission index (STI). The SII method, utilising user-defined, measured, speech signal was found to be the best out of the three metrics for quantifying in-vehicle speech intelligibility. Since the effect of reverberation on the loss of speech intelligibility was negligible, this method resulted in a close correlation with the more measurement-intensive STI method. This potentially provides a reduction in measurement effort while preserving the accuracy of the results.

]]> 10.1504/IJVNV.2011.043193 International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 328 - 346 Nikolina Samardzic; Colin Novak Department of Mechanical, Automotive and Materials Engineering, University of Windsor, 401 Sunset Ave., Windsor, Ontario N9B 3P4, Canada. ' Department of Mechanical, Automotive and Materials Engineering, University of Windsor, 401 Sunset Ave., Windsor, Ontario N9B 3P4, Canada in-vehicle communication articulation index speech intelligibility index speech transmission index passenger communication speech signals vehicle noise. 2011-10-19T23:20:50-05:00 7 4 328 346 2011-10-19T23:20:50-05:00 http://www.inderscience.com/link.php?id=43194 Magnetorheological (MR) fluid damper is a kind of intelligent control device that can be used to reduce response of a vibrating member instantaneously with very few moving parts, which is essential in most of the mechanical systems, but challenging. In the present work, a prototype of smart damper using MR fluid (MR damper) is designed based on Bingham plastic model and fabricated to conduct vibration related tests. A sudden damping is obtained as a result of quick change in viscosity and shear stress of the MR fluid in response to the change in magnetic field. Biodegradable oil namely honge oil is proposed as carrier liquid of the MR fluid. The relation between yield stress and magnetic field of the proposed honge oil-based MR fluid is used while designing the MR damper. Then an experimental setup is designed to investigate the damping and vibration control characteristics of the fluid. Damping force at various frequencies, amplitudes and currents are obtained and their inter-relations are studied. Further the acceleration time response of the damper is evaluated at different frequencies of vibration and input currents using Labview software. The results are compared with those of other authors and found to be satisfactory. Investigations on damping characteristics of a honge oil-based magnetorheological fluid damper
B. Gangadhara Shetty; P.S.S. Prasad
International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 347 - 364
Magnetorheological (MR) fluid damper is a kind of intelligent control device that can be used to reduce response of a vibrating member instantaneously with very few moving parts, which is essential in most of the mechanical systems, but challenging. In the present work, a prototype of smart damper using MR fluid (MR damper) is designed based on Bingham plastic model and fabricated to conduct vibration related tests. A sudden damping is obtained as a result of quick change in viscosity and shear stress of the MR fluid in response to the change in magnetic field. Biodegradable oil namely honge oil is proposed as carrier liquid of the MR fluid. The relation between yield stress and magnetic field of the proposed honge oil-based MR fluid is used while designing the MR damper. Then an experimental setup is designed to investigate the damping and vibration control characteristics of the fluid. Damping force at various frequencies, amplitudes and currents are obtained and their inter-relations are studied. Further the acceleration time response of the damper is evaluated at different frequencies of vibration and input currents using Labview software. The results are compared with those of other authors and found to be satisfactory.

]]> 10.1504/IJVNV.2011.043194 International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 347 - 364 B. Gangadhara Shetty; P.S.S. Prasad Department of Mechanical Engineering, PSG College of Technology, Coimbatore-641004, Tamilnadu State, India. ' Department of Mechanical Engineering, PSG College of Technology, Coimbatore-641004, Tamilnadu State, India magnetorheological fluid dampers honge oil dampers displacement frequency damping force vehicle vibration smart dampers biodegradable oil damping. 2011-10-19T23:20:50-05:00 7 4 347 364 2011-10-19T23:20:50-05:00 http://www.inderscience.com/link.php?id=43195 Engine shaft instantaneous angular speed (IAS) can be used to diagnose combustion related faults and other faults affecting the output of engines, especially for small-scale diesel generators. Unfortunately, it is difficult to apply this technology to monitoring the operational condition of a marine propulsion diesel engine due to its complex shafting systems and multiple factors affecting the shafting torsional vibration. In this paper, the characteristics of fault detection based on traditional IAS analysis methods are firstly analysed. A novel method has been developed based on treating the engine shaft system as a flexible model, aiming to extend the IAS technique to monitor the working condition of a large marine diesel engine. Theoretical studies and engine evaluation tests have been conducted on a marine diesel engine experiment set-up. It is shown that an integration of the developed flexible model with traditional IAS technique is feasible and accurate. Fault diagnosis of a diesel engine by using the analysis of instantaneous angular speed with a flexible model
Yonghua Yu; Jianguo Yang; Peilin Zhou
International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 365 - 385
Engine shaft instantaneous angular speed (IAS) can be used to diagnose combustion related faults and other faults affecting the output of engines, especially for small-scale diesel generators. Unfortunately, it is difficult to apply this technology to monitoring the operational condition of a marine propulsion diesel engine due to its complex shafting systems and multiple factors affecting the shafting torsional vibration. In this paper, the characteristics of fault detection based on traditional IAS analysis methods are firstly analysed. A novel method has been developed based on treating the engine shaft system as a flexible model, aiming to extend the IAS technique to monitor the working condition of a large marine diesel engine. Theoretical studies and engine evaluation tests have been conducted on a marine diesel engine experiment set-up. It is shown that an integration of the developed flexible model with traditional IAS technique is feasible and accurate.

]]> 10.1504/IJVNV.2011.043195 International Journal of Vehicle Noise and Vibration, Vol. 7, No. 4 (2011) pp. 365 - 385 Yonghua Yu; Jianguo Yang; Peilin Zhou School of Energy and Power Engineering, Wuhan University of Technology, 1040 Heping Avenue, Wuhan, Hubei, 430063, China. ' School of Energy and Power Engineering, Wuhan University of Technology, 1040 Heping Avenue, Wuhan, Hubei, 430063, China. ' Department of Naval Architecture and Marine Engineering, University of Strathclyde, Henry Dyer Building, 100 Montrose Street, Glasgow, G4 0LZ, UK marine diesel engines instantaneous angular speed fault diagnosis engine shaft speed flexible models. 2011-10-19T23:20:50-05:00 7 4 365 385 2011-10-19T23:20:50-05:00