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News Article | May 18, 2017

SAE 2017 Noise and Vibration Conference and Exhibition today announced its keynote speakers for the June 12-15 event in Grand Rapids, Michigan. On Tuesday, June 13, the event will open with Professor Ahmet Selamet, the Professor of Mechanical and Aerospace Engineering at the Ohio State University discussing “Flow Instabilities: From Turbochargers to Wind Instruments.” Flow instabilities in the breathing system of engines and the resulting noise are discussed in connection with flow separation and surge in turbochargers, and flow-acoustic coupling in induction systems. The impact of incidence angle at the turbocharger compressor inducer plane is illustrated both in terms of boosting and acoustic performance. Variety of time-resolved measurements for internal pressure, velocity, and temperature reveals the character of instabilities and their consequences. These measurements are complemented by videos from selected experimental observations and animations from pertinent computational predictions. The approach of reproducing the specific engine physics of interest on bench top experimental facilities is particularly emphasized in gaining further insight into the fundamental mechanisms leading to noise as well as in developing effective remedies. Prof. Ahmet Selamet received his Ph.D. in mechanical engineering from University of Michigan in 1989. He joined the Department of Mechanical Engineering of The Ohio State University in 1996, where he was promoted to Professor in 2001. From 2012 to 2016, he also served as the elected Chair of the Department of Mechanical and Aerospace Engineering at The Ohio State University. Selamet’s research centers around nonlinear wave dynamics and acoustics, noise control, combustion, fluid mechanics, and heat transfer as applied primarily to internal combustion engines. Over the past three decades, he has conducted extensive analytical, computational, and experimental work to advance the fundamental understanding of wave dynamics and acoustics in engine breathing systems (induction/in-cylinder/exhaust), including the development and validation of pertinent submodels in engine simulations to improve the performance and noise predictions. Selamet recently has focused his attention on turbocharger acoustics and autoignition in combustion chambers. He has disseminated the research findings in more 215 articles in journals/proceedings and co-authored a book on Heat Transfer. On Wednesday, June 14, Gabriella Cerrato, the Manager of Global Engineering Services at Bruel & Kjaer will give the luncheon keynote speech. She will discuss "Changes and Trends in Noise and Vibration Engineering: The Consultant’s Experience." In her remarks, Gabriella Cerrato will focus on the changes that she has witnessed in the industry and address current trends. She will provide a personal perspective on changes in consumers’ expectations and in NVH technology, along with her assessment of how cultural, geographical, and gender factors have shaped her experience as a noise and vibration consultant. Gabriella Cerrato has a Doctorate in Theoretical Physics from the University of Torino, Italy. She has worked in the noise and vibration control field for more than 25 years, with positions ranging from Acoustic Systems Engineer and Manager at FIAT in Italy (Active Noise and Vibration Group) to Technical Director of the MTS Systems consulting business unit in Detroit. Her areas of expertise are diagnostics of noise and vibration concerns, sound and vibration quality measurement and target setting, testing for correlation of CAE models, and synthesis/prediction of contributions to products’ noise and vibration performance. Cerrato co-founded Sound Answers in 2005 and has led the Sound Answers team in several Small Business Innovation Research (SBIR) Phase 1 and Phase 2 projects for the U.S. Department of Defense. She teaches several seminars and training classes a year and has co-authored papers for various professional conferences and magazines. The SAE Noise and Vibration Conference and Exhibition is the premier technical event dedicated to mobility noise, vibration and harshness. Held biennially, this conference serves as a forum for leading automotive, commercial vehicle, and aerospace professionals to share the latest technologies surrounding NVH, and sound quality. The following topics related to vehicle design, engineering and testing will be the focus of the event: For more information about the event, the conference program, or to register, please visit SAE International is a global association committed to being the ultimate knowledge source for the engineering profession. By uniting more than 127,000 engineers and technical experts, we drive knowledge and expertise across a broad spectrum of industries. We act on two priorities: encouraging a lifetime of learning for mobility engineering professionals and setting the standards for industry engineering. We strive for a better world through the work of our philanthropic SAE Foundation, including programs like A World in Motion® and the Collegiate Design Series™.

Freeman T.,Sound Answers Inc | Cerrato G.,Sound Answers Inc
SAE Technical Papers | Year: 2011

Design parameters for automotive components can be highly affected by the requirements imposed for vehicle pass-by compliance. The key systems affecting pass-by performance generally include the engine, tires, intake system, and exhaust system. The development of these systems is often reliant on the availability of prototype hardware for physical testing on a pass-by course, which can lead to long and potentially costly development cycles. These development cycles can benefit significantly from the ability to utilize analytical data to guide development of component-level design parameters related to pass-by noise. To achieve this goal, test and analysis methods were developed to estimate the vehicle-level pass-by performance from component level data, both from physical and/or analytical sources. The result allows for the estimation of the overall vehicle-level pass-by noise along with the contributions to the total and dominant frequency content from each of the key noise sources. This information can be utilized in two distinctly different ways. First, the pass-by noise levels can be estimated for new component-level design alternatives, from either physical testing and/or analytical predictions. Secondly, a target pass-by noise level can be specified and the required acoustic performance for the dominant noise sources can be calculated. Utilizing component-level data to estimate vehicle pass-by performance provides the ability to evaluate multiple design alternatives in a time and cost-effective manner, as well as balance potential countermeasures and design alternatives across multiple noise sources. Dependency on physical prototype hardware can be reduced, allowing for estimation of pass-by noise levels with reduced reliance on vehicle-level testing. Copyright © 2011 SAE International.

Green E.R.,Sound Answers Inc
INTER-NOISE 2015 - 44th International Congress and Exposition on Noise Control Engineering | Year: 2015

As the requirements for realistic analytical modeling become greater, the need to test automotive intake components under realistic conditions for correlation purposes increases accordingly. Sound pressure levels in automotive intake systems reach levels as high as 170 dB at the throttle body and firing frequencies can be as low as 20 Hz. At these high sound levels, nonlinear effects are observed due to drain holes and flexure of non-circular cross-sections. Testing at low frequencies is challenging because transitions used to match the area of the test components to the area of the tube produce significant low frequency errors for which corrections need to be made. A test system and data processing procedures to address these issues are presented. © 2015 by ASME.

Cerrato G.,Sound Answers Inc
SAE Technical Papers | Year: 2010

For the development of a self-propelled crop spraying machine, a hybrid experimental and analytical Source-Path-Contribution (SPC) approach is utilized by a leading agricultural equipment manufacturer. The objective is to predict noise and sound quality in the cab before prototypes are assembled, so that dB(A) and SQ targets can be assessed early on and better specifications sent to suppliers to achieve these vehicle-level targets. The experimental SPC task is conducted on the current crop sprayer model, which has the same cab but different engine, transmission and hydraulics than the new model. A hybrid FE-SEA model of the current cab is developed and run at load cases derived from test data. The SEA approach is needed to evaluate the effect of cab acoustic treatments, which are not accounted for in the SPC experimental model. Contributions to in-cab noise for the current sprayer are estimated from both experimental and analytical SPC. Acoustic and structural loads to the cab in the new model are estimated from measurements on hardware components and from supplier provided data. The hybrid FE-SEA model is then updated with the new loads and re-run to predict total in-cab noise and contributions from each source in the new model, which is then used to identify the best countermeasures for noise reduction and SQ improvement. Copyright © 2010 SAE International.

Pietila G.,Sound Answers Inc | Cerrato G.,Sound Answers Inc
Sound and Vibration | Year: 2012

The field of sound quality is very advanced in the automotive industry. In recent years it has also become an important marketing and engineering factor in other industries. The biggest differences in SVQ (Sound/Vibration Quality) perception between passenger vehicles and other products lie in the human machine interface and the modality of the interaction. Both factors strongly impact expectation. When driving, we fully "experience" the vehicle, since we are immersed in it through multiple and distributed interfaces that make our perception truly multimodal. Furthermore, the driving experience is, in almost all conditions, very interactive in nature. Instead, when we use a vacuum cleaner or we install an air purifier in a room, our interface with either product is simpler, often limited to our aural perception of its noise and only at times supplemented by a tactile dimension, as in the case of the vacuum cleaner. Additionally, with many consumer products, our experience is intrinsically passive, because we do not interact with the product other than turning it on or off, as is the case with appliances, air conditioners, generators, etc.

The Sound Transmission Loss of automotive intake and exhaust components is commonly measured using the four microphone tube method per ASTM E2611 [1]. Often area adapters are used to match the component diameter to that of the tube apparatus. These area adapters affect the Sound Transmission Loss measurement, especially at very low frequencies. The use of the Transfer Matrix Technique to remove the effect of the area adapters is described. The improvements for step and cone area adapters are compared. Copyright © 2015 SAE International.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase I | Award Amount: 149.60K | Year: 2015

ABSTRACT:Noise levels of military jet aircraft have significantly increased as the power of the engines has increased creating a community noise issue around military airfields. Current noise monitoring requirements only measure sound pressure levels which do not correlate to human annoyance / disturbance. Sound Answers plans to apply their extensive Sound Quality background to establish new acoustic time- and frequency-based metrics which will correlate to human perception for annoyance/disturbance. Then, Sound Answers staff will apply their Noise & Vibration troubleshooting methods to evaluate various acoustic array technologies to identify the most efficient / cost effective method for cascading the new annoyance metric results to actual design features of the jet engine in an effort to reduce the annoyance levels of the new aircraft. The final deliverable will be a Matlab-based toolbox integrated into Sound Answers Time Frequency Analyzer Core (TFAC) software and will also be embedded in current commercial software packages used for acoustic monitoring at airports.BENEFIT:- Civil and Military Aircraft manufacturers, who can specify noise requirements to engine manufacturers in light of annoyance in the far-field. - Jet engine manufacturers, who can implement better near-field noise test procedures to validate their product, increase their noise diagnostic capabilities and be more effective in identifying areas of noise reduction - Government agencies, in the US and abroad, who can apply the new annoyance/disturbance metrics to improve the power of their Community Noise Impact tools.

Sound Answers Inc | Date: 2013-10-08

computer software for noise and vibration troubleshooting.

Agency: Department of Defense | Branch: Air Force | Program: SBIR | Phase: Phase II | Award Amount: 750.00K | Year: 2010

The US Air Force needs a system to help identifying root-causes of jitter in HEL beam alignment systems. This is of particular interest to the USAF as jitter smears the HEL beam on target, reducing its integrated intensity and therefore its target damage capability. Jitter is caused by several disturbances introduced in the beam alignment system with multiple sources and complex interactions between the multitude of sub-systems and components. With the current state-of-the art it is not possible to unequivocally identify sources of jitter from the analysis of the jitter signal alone. Rather, a comprehensive, yet streamlined and efficient, test plan to map the relevant sub-systems/components is required. A process has been established using strategic measurement techniques and advanced signal processing algorithms to quantify the jitter sources and paths in a consistent and accurate manner. This process will be further developed by testing on a variety of different HEL beam control installations to ensure the algorithms are optimized to effectively address jitter in all applications. The algorithms and test process with then be developed into a “Jitter Vibration Decomposition Toolbox” software program to allow increased efficiency for testing personnel to perform jitter analysis. BENEFIT: The primary objective of this Phase II project is to deliver to the USAF test and signal analysis tools to decompose beam jitter into its most important contributions. The immediate benefit is for time and cost savings during the integration phase of an HEL system when much of the jitter root-cause investigation takes place. The improvement in testing efficiency and more applicable output will lead to the supplier base implementing updated test procedures to impact their design process with updated models and more informed design decisions. This need for better and more efficient testing methods is not unique and the automated signal processing toolbox developed in this Phase II project will be the core for developing similar toolboxes geared towards other industries such as automotive, consumer products and off-highway.

Agency: Department of Defense | Branch: Army | Program: SBIR | Phase: Phase I | Award Amount: 69.97K | Year: 2010

The proposed approach starts from an investigation of psychophysical stimuli relevant to the detection of a vehicle in an urban environment. Existing simulators will then be evaluated from the standpoint of their capability of high fidelity reproduction of real stimuli and on their ability to handle virtual stimuli (i.e. from virtual vehicles). Sound Answers will follow an iterative approach to the development of a multi-modal detectability metric, by first conducting experiments of vehicle detection based on one type of high quality cue (as an example, just visual or audio or vibration). Bi-modal detection experiments will then be conducted by using the (one or more) simulators that offer best signal quality for at least two stimuli. The results of both series of experiments will be analyzed to derive a detectability model based on one stimulus only, then a detectability model which accounts for the cross-coupling among two stimuli at a time. Finally, a hypothesis of a multi-modal metric model will be formulated along with a specification document for the simulator to be built in Phase 2.

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