Your Selections

Exterior noise
Show Only

Collections

File Formats

Content Types

Dates

Sectors

Topics

Authors

Publishers

Affiliations

Committees

Events

Magazine

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Computational Process to Effectively Design Seals for Improved Wind Noise Performance

Dassault Systemes SIMULIA-Robert Powell, Sivapalan Senthooran, Philippe Moron
Jaguar Land Rover-Nicholas Oettle
Published 2019-06-05 by SAE International in United States
The ability to assess noise transmitted through seals to cabin interiors early in the design process is very important for automotive manufacturers. When a seal design is inadequate, the noise transmitted can dominate the interior noise, making the wind noise performance of the vehicle unacceptable. This can cause launch delays, increasing costs and risking loss of sales. Designing seals using conventional experimental processes is challenging, since the location and strength of flow noise sources are not known when the seal design is planned. Making changes to the seal system after the tooling stage is expensive for manufacturers as tooling and redesign costs can be considerable. Deliberate overdesign by adding multiple layers of seals in a wide range of locations also can reduce profit by unnecessarily raising part and manufacturing costs. Consequently, there is a strong motivation to use reliable computational capabilities to predict interior noise transmitted through seals early in the design process to address these challenges, designing seals right first time.The current study presents a computational process that can be used to predict interior…
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Exterior Acoustics Using Infinite Elements

Altair Engineering-Anurag Rajagopal, Dilip Mandal, Junji Saiki, Ujwal Patnaik
Published 2019-06-05 by SAE International in United States
The idea of employing an infinite element to solve acoustic problems in an unbounded domain has demonstrated significant promise. Starting from first principles, the detailed element formulation for a mapped wave-envelope infinite element is presented. This, in conjunction with an efficient search algorithm to map receiver grid locations to the pertinent infinite element on the boundary, is used to enhance an established finite-element based vibro-acoustic solver for frequency response in order to solve large scale industrial problems. The solver is then subjected to a thorough validation and verification study using problems whose solutions are established either through classical texts or alternative approaches to demonstrate the accuracy, robustness and efficiency of the current solution.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Influence of Rib Stiffener Design Parameters on the Noise Radiation of an Engine Block

SAE International Journal of Engines

Ford Otosan, Research and Development Center, Turkey-Çiğdem Karaca
Istanbul Technical University, Turkey-Ender Balcı, Ozgen Akalin
  • Journal Article
  • 03-12-02-0013
Published 2019-03-14 by SAE International in United States
Stiffener ribs are widely used to increase the stiffness of engine blocks, shifting the vibration modes to higher frequencies where excitation is weaker so that radiated noise can be reduced. The effect of different rib design parameters on the radiated noise emission of a diesel engine has been investigated considering its impact on block weight. A heavy-duty engine block was modeled using finite element method, multi-body dynamics approach was used to determine the excitation forces acting due to combustion pressure and inertias, and boundary element method was used to find the acoustic transfer vectors which give the relationship between engine surface velocities and sound pressure levels at predetermined microphone locations. Initially, the baseline analytical sound pressure level and surface velocity results for the engine without ribs were obtained. Two prototype engines, with and without stiffened ribs, were tested in an acoustic dynamometer in complete speed range. Then, the problem was narrowed down to a specific surface patch on the block at a critical engine speed. The effects of various ribbing design parameters have been identified…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

A Pass-By Noise Prediction Method Based on Source-Path-Receiver Approach Combining Simulation and Test Data

SAE International Journal of Advances and Current Practices in Mobility

ESI Group-Massimiliano Calloni, Chadwyck Musser, Abderrazak Mejdi, Augusto Medeiros
ESI North America-Alexis Castel
  • Journal Article
  • 2019-26-0188
Published 2019-01-09 by SAE International in United States
Optimizing noise control treatments in the early design phase is crucial to meet new strict regulations for exterior vehicle noise. Contribution analysis of the different sources to the exterior acoustic performance plays an important role in prioritizing design changes. A method to predict Pass-by noise performance of a car, based on source-path-receiver approach, combining data coming from simulation and experimental campaigns, is presented along with its validation. With this method the effect of trim and sound package on exterior noise can be predicted and optimized.
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Aero-Acoustics Noise Prediction of 3D Treaded Tyre Using CFD

ANSYS INDIA PVT LTD.-Bhanu Gupta
CEAT LTD.-Chirag Bharatbhai Patel, Sharad Goyal, Abhishek Saraswat
Published 2019-01-09 by SAE International in United States
Tyre exterior noise legislation (pass-by) is becoming more stringent with time. To cater to these requirements, it is very important to understand the tyre noise generation and enhancing mechanisms such as air pumping, air turbulence, pipe resonance, horn effect in high frequency region from 500Hz to 4000Hz. These phenomena are affected by air flow around and within the tyre pattern hence, CFD based approach is chosen for tyre exterior noise. The CFD based methodology helps in fine tuning the tread pattern to reduce aero acoustic noise level which leads to reduction in the product design cycle time. In present study, 3d transient CFD aero-acoustic modelling approach results were validated against the anechoic tyre rolling noise test data which captures the air-born noise mechanisms for frequency range of 1 kHz to 4 kHz.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Sound Level for Passenger Cars and Light Trucks

Light Vehicle Exterior Sound Level Standards Committee
  • Ground Vehicle Standard
  • J986_201808
  • Current
Published 2018-08-10 by SAE International in United States

This SAE Standard establishes the test procedure, environment, and instrumentation for determining the exterior sound level for passenger cars, multipurpose vehicles, and light trucks having a gross vehicle mass rating of 4540 kg or less. The test procedure is characterized by having fixed initial conditions, i.e., an as-specified initial vehicle speed and gear selection at a fixed start point on the test site. Full-throttle acceleration and closed-throttle deceleration of the vehicle are included in this procedure.

   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Passive Treatment Solutions for the Reduction of Vehicle Exterior Tire Noise

Autoneum Holding AG-Thibault Lafont, Jan Horak, Roberto D'Amico, Rainer Stelzer, Claudio Bertolini
Published 2018-06-13 by SAE International in United States
The recently updated pass-by noise measurement procedure prescribes a mix of acceleration tests and constant speed tests. This has led to an increased relevance of tire noise relative to the past, when the procedure prescribed only acceleration tests. In addition, the next phase of the roadmap for pass-by noise limits for passenger vehicles is 70 dB(A) by 2020, later followed by 68 dB(A). In this context, exterior tire noise has drawn increasing attention. OEMs, suppliers of passive acoustic treatments, road manufacturers and tire manufacturers are, at the moment, devoting strong efforts to the definition of solutions for the control of exterior noise.This paper is concerned with the potential of existing passive exterior treatments to reduce the exterior noise generated by the tires. Different countermeasures are analyzed, namely wheelhouse liners, under-engine shields, under-body panels and under-trunk panels. The goal is to provide a sensitivity analysis with respect to the absorption characteristics and a ranking of the relevance of these treatments in the perspective of taking rational decisions to lessen the exterior noise. Results are based, on one hand,…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Investigation of Interior Noise from Generic Side- View Mirror Using Incompressible and Compressible Solvers of DES and LES

Aero-Vibro Acoustics-Huadong Yao
Chalmers University of Technology-Lars Davidson
Published 2018-04-03 by SAE International in United States
Exterior turbulent flow is an important source of automobile cabin interior noise. The turbulent flow impacts the windows of the cabins to excite the structural vibration that emits the interior noise. Meanwhile, the exterior noise generated from the turbulent flow can also cause the window vibration and generate the interior noise. Side-view mirrors mounted upstream of the windows are one of the predominant body parts inducing the turbulent flow. In this paper, we investigate the interior noise caused by a generic side-view mirror. The interior noise propagates in a cuboid cavity with a rectangular glass window. The exterior flow and the exterior noise are computed using advanced CFD methods: compressible large eddy simulation, compressible detached eddy simulation (DES), incompressible DES, and incompressible DES coupled with an acoustic wave model. The last method is used to simulate the hydrodynamic and acoustic pressure separately. The pressure fluctuations of the flow and noise are imposed on the window in the computation of the interior noise, but the reversal effect of the window vibration feeding back on the flow…
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Evaluation and Improvement of Greenhouse Wind Noise of a SGMW SUV using Simulation Driven Design

Exa Corporation-Long Wu, Weiliang Xie, Heinz Friz
SAIC GM Wuling Automobile Co., Ltd.-Zhaoping Hou, Nian Fu, Yuanyi Huang cEng, Juncheng Lv
Published 2018-04-03 by SAE International in United States
At SAIC-GM-Wuling (SGMW) the greenhouse wind noise performance of their vehicles has gained a lot of attention in the development process. In order to evaluate and improve the noise quality of a newly developed SUV a digital simulation based process has been employed during the early stage of the design. CFD simulation was used for obtaining the flow induced exterior noise sources. Performance metrics for the quality were based on interior noise levels which were calculated from the exterior sources using a SEA approach for the noise transmission through the glass panels and propagation to the driver’s or passenger’s head space. Detailed analysis of the CFD results allowed to identify noise sources and related flow structures. Based on this analysis, design modifications were then applied and tested in a sequential iterative process. As a result an improvement of more than 2 dB in overall sound pressure level could be achieved.
This content contains downloadable datasets
Annotation ability available
   This content is not included in your SAE MOBILUS subscription, or you are not logged in.

Noise Source Identification and Exterior Noise Reduction of a Commercial Vehicle

Ashok Leyland Technical Center-Prasad Padavala, Judsonrajkumar Thaveedu, G Senthilkumar, Jaganmohan Rao Medisetti
Published 2017-07-10 by SAE International in United States
Exterior noise reduction of a vehicle has become important nowadays in order to meet the stringent pass by noise regulations. First step in this process is the identification of dominant noise sources. There are several noise sources which can contribute to the pass by noise like gearbox, turbocharger, oil sump, exhaust muffler, air intake etc. The dominant noise sources can be identified with the near field noise, component vibration measurements combined with experimental modal analysis. This paper discusses about the noise source identification and exterior noise reduction of a shortest wheel base intermediate commercial vehicle, which is having a 4-cylinder inline diesel engine.
This content contains downloadable datasets
Annotation ability available