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Development, System Integration and Experimental Investigation of an Active HVAC Noise Control System for a Passenger Car

Fraunhofer Institute LBF-Jonathan Millitzer, Valentin Mees, Christopher Ranisch
Hyundai Motor Company-Joong-Kwan Kim, Jinmo Lee, ChiSung Oh, Kang-Duck Ih
  • Technical Paper
  • 2020-01-1538
To be published on 2020-06-03 by SAE International in United States
Current developments in the automotive industry such as electrification and consistent lightweight construction increasingly enable the application of active control systems for the further reduction of noise in vehicles. As different stochastic noise sources such as rolling and wind noise as well as noise radiated by the ventilation system are becoming more noticeable and as passive measures for NVH optimization tend to be heavy and construction space intensive, current research activities focus on the active reduction of noise caused by the latter mentioned sources. This paper illustrates the development, implementation and experimental investigation of an active noise control system integrated into the ventilation duct system of a passenger car. Making use of a model-based design process, the development is based upon a holistic numerical simulation model integrating a reduced order acoustic model derived from finite element simulations as well as simplified loudspeaker and microphone characteristics. The numerical simulation assists the selection of a suitable loudspeaker microphone configuration, taking into account the available installation space and the integration of low-cost loudspeakers and MEMS microphones. The ventilation…
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Robust Development of Electric Powertrain NVH for Compact Electric SUV

Hyundai Motor Company-Tae-Won Ha, Jin-Wook Huh, Sang-Kyu Choi, Dong-Wook Min, Chang-Kook Chae
Romax Technology-Annabel Abdy, Carsten Schmitt, Hanafy Mahmoud, Sharad Jain, Leon Rodrigues
  • Technical Paper
  • 2020-01-1503
To be published on 2020-06-03 by SAE International in United States
Electric vehicles (EV's) present new challenges to achieving the required noise, vibration & harshness performance (NVH) compared with conventional vehicles. Specifically, high-frequency noise and abnormal noise, previously masked by the internal combustion engine can also cause annoyance in an EV. Electric motor (E-motor) whine noise caused by electromagnetic excitation during E-motor operation is caused by torque ripple and stator local excitation. Under high speed and high load operating conditions, the sound level is low, however high frequency whine noise is a factor that can impair the vehicle level NVH performance. An example of a previously masked abnormal noise is a droning noise that can be caused by manufacturing quality variation of the spline coupling between the rotor shaft of the E-motor and the input shaft of the reducer, it is dominated by multiple higher orders of the E-motor rotation frequency. In this study, the high speed and high load condition whine noise problem was reproduced through electromagnetic and structural analysis, and the countermeasure (E-motor geometry refinements to reduce the excitations and mechanical system transfer path…
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Estimation the Interior Sound Quality in BEV's Regarding Measurements on the Roller Test Bench: Focusing on Tonal Omponents

AVL Deutschland GmbH-Daniel Schecker, Eugen Deisling, Peter Uerlings
  • Technical Paper
  • 2020-01-1542
To be published on 2020-06-03 by SAE International in United States
Development of BEVs gains more and more importance for OEMs, Tier 1s and DSPs and the project volumes continue to grow steadily. Even though the complexity of electric drive trains is reduced in comparison to combustion drive lines, the requirements for NVH development increases. Masking effects of noise through combustion noise fall away, the overall noise level decreases and the high frequency noises from the electric motors, inverters and transmissions dominate the overall impression of this new technology. Because of the missing combustion noise also noises like rolling noise from tires and wind noise is felt more and more disturbing for customers and pedestrians. The NVH character of any vehicle is highly dependent on its operating condition. With BEVs, it mainly depends on the vehicle speed, torque, temperature and state of charge of the battery. For this reason customers usually want to measure many speed-ups with constant torque steps. During a 3 Year cooperation with a big OEM almost all premium BEVs on the German market were measured/benchmarked to get a feedback about the own…
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HEV Evaluation in Simulation Phase Based on Predicted Sound Behavior

AVL LIST GmbH-Paco Langjahr, Markus Resch, Bernhard Graf
  • Technical Paper
  • 2020-01-1511
To be published on 2020-06-03 by SAE International in United States
Grown interest in complex modern Hybrid Electric Vehicle (HEV) concepts has raised new challenges in the field of NVH. The switch between Internal Combustion Engine (ICE) and Electric Motor (EM) at low speeds produces undesirable vibrations and a sudden raise of noise levels that affects the sound quality and passenger comfort achieved by the close-to-silent electric powertrain operation. Starting the ICE in the most suitable driving situation to create a seamless transition between driving modes can be the key to minimize the NVH quality impact in driver and passenger’s perception in HEVs. To integrate this important aspect in the early stages of the development and design phase, simulation technologies can be used to address the issue. By analyzing NVH measurements, the different noise components of the vehicle operation can be separated into ICE-related noise, EM-related noise and driving noise. To achieve highest system flexibility, these noise components can be synthesized, providing an integral NVH assessment tool that can be adapted to different driving conditions. ICE and EM noise are simulated using additive synthesis of an…
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Numerical Investigation of Narrow-Band Noise Generation by Automotive Cooling Fans

Chalmers University of Technology-Omar Fares, Huadong Yao
Volvo Car Group-Chenyang Weng, Linus Zackrisson, Magnus Knutsson
  • Technical Paper
  • 2020-01-1513
To be published on 2020-06-03 by SAE International in United States
Axial cooling fans are commonly used in electric vehicles to cool batteries with high heating load. One drawback of the cooling fans is the high aeroacoustic noise level resulting from the fan blades and the obstacles facing the airflow. To create a comfortable cabin environment in the vehicle, and to reduce exterior noise emission, a low-noise installation design of the axial fan is required. The purpose of the project is to develop an efficient computational aeroacoustics (CAA) simulation process to assist the cooling-fan installation design. This paper reports the current progress of the development, where the narrow-band components of the fan noise is focused on. Two methods are used to compute the noise source. In the first method the source is computed from the flow field obtained using the unsteady Reynolds-averaged Navier-Stokes equations (unsteady RANS, or URANS) model. In the second method, the azimuthal modes of the flow field obtained using the steady RANS with the moving reference frame model are treated as the sound source. While the first method is able to resolve any…
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Wind Tunnel Test to Determine Pantograph Noise Contribution on a High-speed Train

Korea Railroad Research Institute-Heemin Noh
  • Technical Paper
  • 2020-01-1517
To be published on 2020-06-03 by SAE International in United States
In this study, we investigated the characteristics and the influence of the aero-acoustic noise generated from a pantograph using various experimental approaches in a wind tunnel. First, the noise generated at various flow velocities was measured and analyzed using a full-scale pantograph model. Then, the noise generated from the main position of the pantograph was derived using a microphone array attached to one side of a wind tunnel. The noise contributions of the main components of the pantograph were derived from the noise measurements obtained from a step-by-step disassembly of the full-scale model.Through this study, we have investigated the aero-acoustic noise contribution of the major components of a pantograph, and we have developed effective noise-reduction measures for the panhead collector.
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Time Domain Full Vehicle Interior Noise Calculation from Component Level Data by Machine Learning

Mercedes-Benz AG-Dimitrios Ernst Tsokaktsidis, Clemens Nau
Technical University of Munich-Steffen Marburg
  • Technical Paper
  • 2020-01-1564
To be published on 2020-06-03 by SAE International in United States
Computational models directly derived from data gained increased interest in recent years. Data-driven approaches have brought breakthroughs in different research areas such as image-, video- and audio-processing. Often denoted as Machine Learning (ML), these approaches are not widely applied in the field of vehicle Noise, Vibration and Harshness (NVH) yet. Related works mainly discuss the topic with respect to structural health monitoring, psychoacoustics, traffic noise and as improvement to existing numerical simulation methods. Vehicle interior noise is a major quality criterion for today’s automotive development. To estimate noise levels early in the development process, deterministic system descriptions are created by utilizing time-consuming measurement techniques. This paper examines whether pattern-recognizing algorithms are suitable to improve the prediction process for a steering system. Starting from operational measurements, a procedure to calculate the sound pressure level in the passenger cabin is developed and investigated. Component time domain data serves as basis for the computation. The important inputs are determined by a correlation analysis. Input selection is followed by data reduction. After preprocessing, a supervised learning environment is established.…
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Multi-Frequency Model Reduction for Uncertainty Quantification in Computational Vibroacoustics of Automobiles

Groupe PSA-Laurent Gagliardini
Groupe PSA, Université Gustave Eiffel-Justin Reyes
  • Technical Paper
  • 2020-01-1583
To be published on 2020-06-03 by SAE International in United States
This paper deals with the vibroacoustics of complex systems over a broad frequency band of analysis. The system under consideration is composed of a complex structure coupled with an internal acoustic cavity, such as the one encountered in automotive industry. The complex structure is defined by a complex geometry, constituted of heterogeneous materials and of two types of structural levels: a stiff main part and numerous flexible sub-parts. In such a structure, the vibroacoustics model is represented by the usual global-displacements elastic modes associated with the main part, and by numerous local elastic modes, which correspond to the preponderant vibrations of the flexible sub-parts. However, in the framework of automobile vibroacoustic modeling, the main difficulty is the interweaving of the global displacements with the numerous local displacements, which introduce an overlap of the usual three frequency domains (low- (LF), medium- (MF), and high frequency (HF)). In the automotive industry, computational vibroacoustic models are used for predicting the internal noise levels. However, the dimension of computational vibroacoustic models is very high. In this paper, a computational…
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Tire NVH Optimization for Future Mobility

CEAT Ltd-Rahul R. Sanghani, Thomas Cherian, Subramaniam Loganathan, Kamal Suhalka, Juban Thomas
  • Technical Paper
  • 2020-01-1520
To be published on 2020-06-03 by SAE International in United States
Vehicle NVH (Noise, Vibration and Harshness) is one of the most critical customer touchpoints which may lead to buying decisions. The importance of Noise inside the cabin is increasing day by day because of the new era of E-mobility and autonomous driving. Noise source could be the engine, powertrain, tyre, suspension components, brake system, etc. depending on driving conditions. Among these, tire noise is being identified as biggest contributor at constant mid-speed driving where engine and powertrain operate at minimum noise and wind noise is also at a moderate level. This driving condition becomes very significant for electric vehicles where engine noise is replaced by motor noise which is a tonal noise at very high frequency. This makes the improvement of tire noise levels quintessential for good cabin acoustic feel. This demands a proactive approach to develop low noise tire platforms for future mobility by leveraging research tools and best practices in the industry. With a greater emphasis on ride and comfort in passenger car vehicles, tyre manufacturers will be challenged to meet stringent harshness…
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Optimization Of Vehicle Damping Sheets Position Based On Energy Calculation

BAIC Motor Corporation., Ltd-Lie Wu, Huimin Zhuang, Bin Hou
Beijing Automotive Technology Center Co.-Zhiwen Wang, Na Li, Yuping Miao
  • Technical Paper
  • 2020-01-1528
To be published on 2020-06-03 by SAE International in United States
As a common means for reducing vibration and noise for automobiles, damping material is usually employed in the vehicle body, typically on the floor, the dashboard, and the top roof. With the growing demand of fuel economy, light weighting, as well as NVH comfort, the optimization of the damping pads has become a topic of increasing importance. In numerical simulation, the traditional methods generally make use of the modal strain energy of the metal sheet as the main indicator for making layout choice for the damping pads. The optimization is not performed according the vehicle’s real working condition. Furthermore, the traditional methods do not depend on the accurate properties of the damping material. In this paper, a novel optimization method based on energy analysis is presented. This method relies on the subdivision of the vehicle body area into finite number of patches (composed of finite elements), and the energy computation of the vibration and noise indicators when a general damping property (modal damping) is applied on each patch consecutively in a loop. Such operation allows…