Your Selections

Noise measurement
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

 

Psychoacoustic Order Tonality Calculation

HEAD acoustics GmbH-Julian Becker, Roland Sottek
Published 2019-06-05 by SAE International in United States
Quantifying tonalities in technical sounds according to human perception is a task of growing importance. The psychoacoustic tonality method, published in the 15th edition of the ECMA-74 standard, is a new method that is capable of calculating the perceived tonality of a signal. Other methods, such as Prominence Ratio or Tone-to-Noise Ratio do not consider several essential psychoacoustic effects. The psychoacoustic tonality is based on a model of human hearing and thus is able to model human perception better than other methods. The algorithm described in ECMA-74 calculates tonality over time and frequency. In practice, tonalities often originate from rotating components, for example, parts of an electric motor. In these cases, quantification of the tonality of orders is often more interesting than the tonality over frequency. In this paper, an extension of the psychoacoustic tonality according to ECMA-74 is presented. With this extension, it is possible to calculate the order tonalities by using the rotational speed characteristics of the measured signal in order to control the parameters of the auditory filter bank. Two of the…
Datasets icon
Annotation icon
 

Augmenting Vehicle Production Audit with Objective Data and Sound Quality Metrics to Improve Customer Experience in a Changing Automotive Landscape

Bruel & Kjaer Sound and Vibration A/S-Brian Thom, Gabriella Cerrato
Ford Motor Company-Mark Sturgill
Published 2019-06-05 by SAE International in United States
Vehicle manufacturers face increasing challenges in auditing the build quality of their vehicles while considering increasing consumer demands regarding NVH performance. This effect is compounded with the rise in electric and hybrid vehicles. The ability to audit vehicles for a variety of noise types is becoming increasingly important; these include powertrain noise, road noise, and wind noise. An automated measurement system was developed with specific algorithms and sound quality metrics to not only audit vehicle production quality but to add objective data, pass-fail criteria, and trend analysis.
Annotation icon
 

Dual Clutch Transmission Vibrations during Gear Shift: A Simulation-Based Approach for Clunking Noise Assessment

Politecnico di Torino-Enrico Galvagno, Luca Dimauro, Gianluca Mari, Mauro Velardocchia, Angelo Domenico Vella
Published 2019-06-05 by SAE International in United States
A novel methodology, for the assessment of Dual Clutch Transmission vibrations during gear shifts, is proposed in this paper. It is based on the capability to predict through numerical simulation a typical dynamic quantity used to objectively evaluate the vibrational behavior of a gearbox during experimental tests, i.e. the acceleration of a point on the external surface of the gearbox housing. To achieve this result, a two-step approach is proposed: an accurate simulation of the internal transmission dynamics and an offline uncoupled computation of the gearbox housing acceleration from the output of the simulation. The first step required the definition of a suitable nonlinear lumped parameter model of the car equipped with a DCT that was implemented in Amesim software. The second step, developed as a post processing tool in Matlab, is based on the knowledge of the inertance Frequency Response Functions (FRFs) between a single component of force applied in a bearing and a single component of acceleration in the measurement point. The indices used to assess the clunk severity are peak to peak…
Annotation icon
 

New Psychoacoustic Criteria for Turbocharger Aero Noise

Garrett Advancing Motion-Alexandre Rigault
HBM Prenscia-Fred Kihm, Nicolas Baron
Published 2019-06-05 by SAE International in United States
With ever more stringent regulations related to air pollution and CO2 emissions, there is a growing trend to address this through the downsizing of automotive engines. Turbochargers are used to improve engine power by using exhaust gas energy to provide boosted air pressure for better efficiency. They are a key element in powertrains of today and in the future. During real operating conditions, the rotational speed of a turbo varies greatly making this rotating machinery run in “continuous transient” phases and produces unwanted noises as a result. Recently, we identified a new source of aero noise while developing a new type of turbocharger. Our typical in-house procedure for characterizing usual aero broad band noise source was to use the 3-microphone methodology for measuring the acoustic intensity. However, this methodology is not well adapted if the noise source is tonal, not constant over time and includes high frequency content, which is the case with the new type of turbocharger design and which could create bad noise perception in case of noise transfer into the vehicle cabin.…
Annotation icon
 

How a Tier 2 tackles NVH

Automotive Engineering: June 2019

Stuart Birch
  • Magazine Article
  • 19AUTP06_03
Published 2019-06-01 by SAE International in United States

Saint-Gobain invested in anechoic testing so small components can make a big NVH difference.

Saint-Gobain is a company that understands how vital NVH R&D is for perceived quality. Unwelcome noise is a major challenge in premium cars, but it is the minor components that matter. For Saint-Gobain that means particularly its bearings and tolerance rings. The French company, founded in the 17th century, has become so determined these components can assist with reducing vehicle NVH that it has built its own semi-anechoic chamber, hardly a routine investment for a Tier 2 supplier.

Annotation icon
 

Laboratory Testing of Light-Duty Vehicle Electric Cooling Fan Assemblies for Airflow Performance

Cooling Systems Standards Committee
  • Ground Vehicle Standard
  • J2867_201902
  • Current
Published 2019-02-13 by SAE International in United States
This SAE recommended practice is intended for use in testing and evaluating the performance of light-duty automotive electric engine cooling fan assemblies. These Electric Cooling Fan (ECF) assemblies are purchased by light-duty truck and passenger car OEMs from suppliers. They are purchased as complete assemblies, consisting mainly of the fan(s), motor(s), and shroud (see Figure 1); this Recommended Practice will only consider such complete assemblies. Some purchased assemblies using brush-type motors may also include digital control devices such as power resistors or pulse width modulation (PWM) electronics or local interconnect network (LIN) for speed control. In the case of brushless motor technology, the controller is an integral part of the motor where it also performs the commutation process electronically. The performance measurement would include fan output in terms of airflow and pressure, and fan input electric power in terms of voltage and current. This information could then be used to calculate the efficiency of the assembly, including aerodynamic efficiency of the fan and shroud, and electrical efficiency of the motor. The electric power consumption could…
Datasets icon
Annotation icon
 

Maximum Exterior Sound Level for Snowmobiles

Snowmobile Technical Committee
  • Ground Vehicle Standard
  • J192_201901
  • Current
Published 2019-01-23 by SAE International in United States
This SAE Recommended Practice establishes the instrumentation, test site, and test procedure for determining the maximum exterior sound level for snowmobiles. Sound propagation is directly related to the ground cover and provides the largest variation to the measured result. A correction factor is introduced to improve year-round test repeatability of the results on grass surfaces by correcting their spectrum to be similar to snow-covered spectra. Measured sound pressure levels are also highly dependent on the degree of track slip present when performing the vehicle acceleration. Operators should attempt to limit track slip as much as possible while maintaining the requirements described in 5.1.1.
Datasets icon
Annotation icon
 

Sensitivity Study of Different Damping Treatments Using Simulation and Physical Testing Methodologies on Structure Borne Driver’s Ear Noise Performance in a Premium Hatchback Car

Tata Technologies Limited-Jayeshkumar Raghuvanshi, Amit Palsule, Nitin Bodhale, Ajit Kharade, Atul Pol
Published 2019-01-09 by SAE International in United States
Effective damping treatment of the BIW panels of a vehicle is one of the important NVH enablers to attenuate in-cab structure borne noise and panel vibrations. Adding these damping treatments using physical testing methods at a later stage in a vehicle development program may lead to sub-optimal configuration, mass and cost of these treatments. To counter this, a validated simulation based approach to determine damping treatments must be deployed much upfront in a vehicle development program. Effectiveness of a damping treatment depends on identification of most appropriate application locations on the BIW panels of a vehicle being designed and at the same time on employing most appropriate materials having desired properties for these treatments.For identifying optimized locations of damping treatments in the development of a new Tata car program, simulation based composite modal strain energy method and physical test based sound intensity mapping technique were deployed. In earlier stages of development, much before the physical prototypes of the car were available, the damping treatment locations and appropriate materials were proposed using simulation methodology. Effectiveness of…
Datasets icon
Annotation icon
 

Acoustical Considerations for Engine Test Cells

EG-1E Gas Turbine Test Facilities and Equipment
  • Aerospace Standard
  • ARP5759
  • Current
Published 2018-11-21 by SAE International in United States
This document discusses, in broad and general terms, the subject of acoustical considerations in engine test cells. One of the primary purposes of an engine test cell is to control the noise emanating from the operating engine in order to reduce noise in the surrounding facility and community to acceptable levels. This is done by the design and installation of specialized acoustic elements and features, which need to be fully integrated into the overall test cell design. It should be further noted, that the requirements of acoustic control are critical to the proper operation of the engine, safety of plant equipment and personnel, and meeting local and legal noise requirements.
Datasets icon
Annotation icon
 

Sound Level Determination for Snowmobiles under Typical Trail Operating Conditions

Snowmobile Technical Committee
  • Ground Vehicle Standard
  • J3120_201810
  • Current
Published 2018-10-09 by SAE International in United States
This SAE Recommended Practice establishes the method to determine Sound Level of a snowmobile under typical trail operating conditions. Snowmobiles have different engine power levels that depends on the model.
Datasets icon
Annotation icon