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Equivalent Radiated Power driven optimization for driveline housings using simulation tools to cut-down the project time

VE Commercial Vehicles Ltd-Suresh Kumar Kandreegula, Hemant Nishad, Dheeraj Singh, Kunal Kamal
  • Technical Paper
  • 2019-28-2533
To be published on 2019-11-21 by SAE International in United States
In the field of Automotive industry, being competitive makes you succeed. Industry is moving towards advancement day by day. New technologies to improve fuel efficiency, crash resistance, vehicle noise levels have been trending. At VECV, we have traditionally worked on CAE of driveline housings (clutch housing & transmission housing) based on static, dynamic and transient loadings. Currently, weight optimization technique depends on the structural and dynamic loading conditions, but do not consider acoustic concerns. Powertrain housings are highly prone to vibrations and leads to high level of noise. Noise has been constant issue in the casting components associated to driveline. There have been lot of research going on to reduce the level of noise and vibrations in the vehicle driveline, which ultimately leads to fuel efficiency and ergonomic benefits. Low noise generation can also lead to saving of lot of resources deployed to dampen the noises. In order to capture the acoustic responses of the system and to improve the design based on acoustic responses, a comprehensive analysis of newly developed driveline housings (clutch housing…
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Design and Development of an Exhaust Muffler with Improved Transmission Loss for a Naturally Aspirated Diesel Engine

Prince Shri Venkateshwara Engg. College-Edison Rajasingh
SRM Institute of Science and Technology-Sundararaj Senthilkumar
  • Technical Paper
  • 2019-28-0046
To be published on 2019-10-11 by SAE International in United States
In the last two decades, most of the advances in exhaust systems such as acoustic filters and mufflers had been developed to attenuate noise levels and emissions as per environment norms. The purpose of this research work is to design, analyze and test an exhaust muffler in order to determine the pressure drop and noise reduction in the exhaust system. Computational Fluid Dynamic simulations were performed using ANSYS Fluent 16.2. The muffler diameter and length were chosen where as perforations and baffles were also considered so as to have the maximum pressure drop and noise reduction. This study is aimed at investigating a reactive perforated muffler. Several designs were considered for maximum pressure drop and the best was finally selected for manufacturing. Experimental testing was carried out with the finalized muffler prototype. Further the validation was done on a muffler in which the inlet pressure was found lower than that of the simulated results but the experimental outlet pressure was found higher than the simulated results. The backpressure was found to be less due to…
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Imaging and Vibro-Acoustic Diagnostic Techniques Comparison for a GDI Fuel Injector

Istituto Motori CNR-Luigi Allocca, Daniela Siano, Alessandro Montanaro, Maria Antonietta Panza
  • Technical Paper
  • 2019-24-0058
Published 2019-09-09 by SAE International in United States
This work presents the results of an experimental investigation on a GDI injector, in order to analyze fuel injection process and atomization phenomenon, correlating imaging and vibro-acoustic diagnostic techniques.A single-hole, axially-disposed, 0.200 mm diameter GDI injector was used to spray commercial gasoline in a test chamber at room temperature and atmospheric backpressure. The explored injection pressures were ranged from 5.0 to 20.0 MPa. Cycle-resolved acquisitions of the spray evolution were acquired by a high-speed camera.Simultaneously, the vibro-acoustic response of the injector was evaluated. More in detail, noise data acquired by a microphone sensor were analyzed for characterizing the acoustic emission of the injection, while a spherical loudspeaker was used to excite the spray injection at a proper distance detecting possible fuel spray resonance phenomena. In order to monitor vibration throughout the injection event, the injector was also equipped with an accelerometer sensor, adhesively mounted on the holder. Tests in both dry and fuel injection conditions allowed to distinguish the pure mechanical operation of the injector related to the needle opening and closing, and the effects…
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Benefit of a Lightweight Frunk

Autoneum Management AG-Federico Di Marco, Flavio Pezzani, Andreas Daving, Luca Mazzarella
Published 2019-06-05 by SAE International in United States
Due to the increasing number of battery electric vehicles (BEVs), the engineering fields regarding driving comfort and NVH issues are becoming more and more challenging: many new factors affect the development of BEVs NVH package. The noise sources related to the powertrain are different from the traditional ones of internal combustion engines, for instance due to the presence of tonal components, strong harmonics and potential whining noise.To satisfy NVH specifications and the need for lightweight solutions to increase driving range, it is important to mask as much as possible the noise coming from the engine bay with materials both lightweight and acoustically performing. Moreover, for electric vehicles new interesting solutions are possible with the introduction of new components that do not find room under the hood of ICE or hybrid vehicles. These components, if properly designed, could lead to significant NVH benefits. The present paper reports the NVH effects of one of these new components, the frunk, a small compartment inside the engine bay, functionally similar to the trunk.In this paper, the design-by-simulation of a…
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Structural Vibration and Acoustic Analysis of a 3-Phase AC Induction Motor

Peyman Poozesh
Kettering University-Anand Krishnasarma, Allan Taylor, Javad Baqersad
Published 2019-06-05 by SAE International in United States
This paper aims to study the NVH and acoustic performance of a 3-phase AC induction motor in order to develop an approach to reduce the magnetic component of noise from an electric motor in an electric vehicle (EV). The final goal of this project is to reduce the magnetic component of sound from the motor by making modifications to the end bracket of the motor housing.EVs are being considered the future of mobility mainly due to the fact that they are environment-friendly. As many companies are already investing in this technology, electric drives are set to become extremely popular in the years to come. The heart of an EV is its motor. Modern electric vehicles are quiet, furthermore with the lack of an IC engine to mask most sounds from other components, the sound from the electric motor and other auxiliary parts become more prominent. The primary source of electromagnetic noise in a motor arises from magnetic flux variations in the air gap which interfere with the resonant frequencies of the stator core. These flux…
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Developing a Custom Data Acquisition Software Package for a Self-contained Acoustic Test Facility

Kolano and Saha Engineers, Inc.-Richard Kolano, Sagar Patil, Pranab Saha
Published 2019-06-05 by SAE International in United States
This paper provides an overview of a custom software developed to obtain measurement data in a self-contained acoustic test facility system used for conducting random incidence sound absorption tests and sound transmission loss tests on small samples in accordance with SAE J2883 and J1400 standards, respectively. Special features have been incorporated in the software for the user to identify anomalies due to extraneous noise intrusion and thereby to obtain good data. The paper discusses the thoughts behind developing user-friendly algorithms and graphical user interfaces (GUI) for the sound generation, control, data acquisition, signal processing, and identifying anomalies.
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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…
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Vibro-Acoustic Analysis for Modeling Propeller Shaft Liner Material

General Motors-Rajith R. Jayaratne, Yu Liu, Mark Gehringer, Jeff Rayce, Wallace Hill
Published 2019-06-05 by SAE International in United States
In recent truck applications, single-piece large-diameter propshafts, in lieu of two-piece propshafts, have become more prevalent to reduce cost and mass. These large-diameter props, however, amplify driveline radiated noise. The challenge presented is to optimize prop shaft modal tuning to achieve acceptable radiated noise levels. Historically, CAE methods and capabilities have not been able to accurately predict propshaft airborne noise making it impossible to cascade subsystem noise requirements needed to achieve desired vehicle level performance. As a result, late and costly changes can be needed to make a given vehicle commercially acceptable for N&V performance prior to launch.This paper will cover the development of a two-step CAE method to predict modal characteristics and airborne noise sensitivities of large-diameter single piece aluminum propshafts fitted with different liner treatments. The first step is the use of a traditional CAE software to calculate prop surface response. The second step is a boundary element simulation to calculate prop surface radiated noise under the excitation obtained from the first step. Finally, acceleration and acoustic test data are presented to assess…
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Door Closure Sound Quality Engineering Process

Bruel & Kjaer North America, Inc.-Todd Freeman
Brüel & Kjaer Sound And Vibration A/S-Bret Engels
Published 2019-06-05 by SAE International in United States
An important factor contributing to a customer’s subjective perception of a vehicle, particularly at the point-of-purchase, is the sound created by the passenger doors during closure events. Although these sounds are very short in duration the key systems that control the sounds produced can be highly coupled. Similarly, the necessary efforts required to understand key design criteria affecting the sound can also be highly complex.Within this paper sub-systems affecting the door closure sound are evaluated to understand key structural properties and behaviors toward the contribution to the overall sound produced. This begins with the subjective preferences of typical sounds and the difficulties with both measuring and reproducing these sounds appropriately and leads directly to the target setting and target cascading process. With targets in place, it becomes important to link them with physical measurements of the vehicle and door system to identify the key controlling mechanisms that can be affected through design.The behavior of the door system during a closure event is key for the sound produced and can be studied to understand both the…
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Extensive Correlation Study of Acoustic Trim Packages in Trimmed Body Modeling of an Automotive Vehicle

Free Field Technologies-Markus Brandstetter, Jonathan Jacqmot
Hyundai & Kia Corp.-Ji Woo Yoo
Published 2019-06-05 by SAE International in United States
In the automotive sector, the structure borne noise generated by the engine and road-tire interactions is a major source of noise inside the passenger cavity. In order to increase the global acoustic comfort, predictive simulation models must be available in the design phase. The acoustic trims have a major impact on the noise level inside the car cavity. Although several publications for this kind of simulations can be found, an extensive correlation study with measurement is needed, in order to validate the modeling approaches. In this article, a detailed correlation study for a complete car is performed. The acoustic trim package of the measured car includes all acoustic trims, such as carpet, headliner, seats and firewall covers. The simulation methodology relies on the influence of the acoustic trim package on the car structure and acoustic cavities. The challenge lies in the definition of an efficient and accurate framework for acoustic trimmed bodies. Two different approaches to achieve this objective are reviewed. In the first approach, the acoustic trim package is modeled as a set of…
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