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Aircraft Plenum Air Outlet Optimization Method

Embraer-Fernando Stancato
  • Technical Paper
  • 2020-01-0021
To be published on 2020-03-10 by SAE International in United States
It is possible to observe a growing interest by mobility industry toward a increased passenger comfort perception. This tendency is being characterized in the aviation sector by interior project that would guarantee the passenger comfort in entertainment, ergonomics, lightning, air quality, acoustics and thermal environment. Regarding this last three aspects, the air distribution through the plenum has a great impact on them. In this work it is presented a method to select the best outlet orifice configuration. The method was applied on seven different plenums. Acoustic evaluation was done using a rig experiment. Based on noise levels of each configuration, the dominant frequency range is identified. Objectives metrics, such as overall levels, speech interference level (SIL3) and loudness were applied. Subsequently, subjective analysis was conducted using the paired comparison method. Finally, an acoustic performance classification was established. Draft effect and air temperature distribution inside the cabin was done using CFD simulation. Besides that, a one-dimensional duct model was done for each configuration to evaluate plenum velocity and pressure distribution. Through these models, it was possible…
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Sensor Fusion Concept for Improved Rotational Speed Measurement in Small Engines

Institute of Electrical Measurement and Measurement Signal P-Markus Neumayer, Thomas Bretterklieber, Thomas Suppan
  • Technical Paper
  • 2019-32-0519
To be published on 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Future developments for small engines, e.g. engines for handheld working tools, like chain saws require the integration of ECU-systems for engine control. For small engines often only a rotational speed senor is available. The application of additional engine sensors is in many cases unwanted, e.g. due to cost aspects and additional wiring. The lack of sensor data requires tailored control strategies and signal processing techniques to infer information about the engine from the sensor data. E.g. for rotational speed sensors the Δω method has been proposed, where the load is estimated from the temporal variation of the rotational speed. This approach requires a rotational speed sensor with sufficient angular resolution. In this paper we present a simulation study for a sensor fusion concept to improve the temporal resolution of engine speed measurements for low cost engines by means of an additional vibration sensor. The rotational sensor of the engine is assumed to have insufficient resolution to determine variations of the rotational speed over an engine revolution. However, variations of the rotational speed of the engine…
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High Frequency Vibration Transmission Analysis on Agricultural Tractor by Using Combined Dynamical Energy Analysis and Transfer Path Analysis Approach

University of Nottingham-Gregor Tanner, Martin Richter
Yanmar R&D Europe s.r.l-Satoshi Morita
  • Technical Paper
  • 2019-32-0527
To be published on 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Dynamical Energy Analysis (DEA) has recently been introduced as a mesh-based high frequency method modelling structure borne sound for complex built-up structures. Using DEA, the structure-borne sound of an assembled agricultural tractor was calculated and good agreement between measurement and DEA calculations has been shown. However, it is still difficult to model a solid structure as currently DEA is based on wave-transmission calculations through plates and plate-to-plate junctions. Additionally, it is often difficult to generate accurate FE meshes of assembled complex structures because of welds, bolts, and rubber brushes between components. In this paper, we propose a novel method to generate DEA elements based on measurement data in order to model solid parts of a complex structures. The method of Advanced Transfer Path Analysis (ATPA) is employed to extract energy-transmission characteristics of a structure. Firstly, Frequency Response Functions (FRFs) are measured between interface points on a structure. Then the direct transfer functions between all interface points are calculated using ATPA. Finally, DEA elements connecting interface points are calculated. They are based on the ATPA result…
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A Study of the Control Logic of Electronically Controlled Suspension for Motorcycle

Kawasaki Heavy Industries, Ltd.-Takenori Terada, Kazuhiro Ichikawa, Hideyuki Kato, Taro Iwamoto
  • Technical Paper
  • 2019-32-0569
To be published on 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Electronically controlled suspensions are expected to improve driving performance as the damping characteristics of the suspension can be adjusted in real time to respond to road conditions. This paper reports the results of testing the suspension control logic for improving ride quality, especially when driving on rough roads, using an internally developed riding simulator.The skyhook theory is widely known as a control logic for reducing vibration when driving a four-wheeled vehicle on a rough road, which we utilized in our riding simulator to examine the vibration reduction effects when applying control logic for motorcycle suspensions. The test results show that the skyhook theory can be applied in motorcycles.However, sensors for suspension systems that can be installed in mass-produced motorcycles are severely limited in terms of cost and space. Therefore, we examined a control logic based on skyhook theory that can reduce vibration even with a simple and inexpensive sensor system.A novel control logic was successfully designed that implements the relationship between the suspension stroke speed and the vertical acceleration of the sprung mass from the…
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A Study on the Decay Process in the Time-Frequency-Dependent Combustion-Noise-Generation Model for Diesel Engines

Graduate School of Sciences and Technology for Innovation, Y-Hitoshi Oguchi, Masato Mikami
  • Technical Paper
  • 2019-32-0512
To be published on 2020-01-24 by Society of Automotive Engineers of Japan in Japan
We experimentally investigated the process of decay of engine noise from a single-cylinder diesel engine considering the time-frequency-dependent combustion-noise-generation model. In this model, the vibration energy of each frequency component is assumed to accumulate in the engine structure excited by the combustion impact during the combustion period in a cycle and decay over time, and the combustion noise is assumed to radiate from the engine surface. We used wavelet transform analysis as a time-frequency analysis of the sound pressure to obtain the decay rate, c, of the engine noise power. In order to investigate the dependence of the decay rate, c, on the sound-source location, we placed eight microphones in different positions near the engine. In order to investigate the dependence of the decay rate on the maximum in-cylinder pressure rise, we conducted experiments under three different operating conditions. The shape of the temporal variation of the engine-noise power depended on the sound-source location while the value of the engine noise power depended on the maximum in-cylinder pressure rise. Based on the time-frequency-dependent combustion-noise-generation model,…
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Acoustics and Drivability as the Main Drivers for Customer Satisfaction for electrified 2-Wheeler

AVL List GmbH, Austria-Christian Hubmann, Patrick Falk, Bernhard Graf, Hubert Friedl
  • Technical Paper
  • 2019-32-0525
To be published on 2020-01-24 by Society of Automotive Engineers of Japan in Japan
Along with the global trend for electrification, also motorcycle industry is entering new spheres of highly advanced products and is increasing customer demands for electric mobility. Beside hard facts such as performance, driving range, durability and ease of use, also the brand specific attributes such as styling, driveability and even sound for electrified 2-wheeler are very emotional, unique selling prepositions. To determine the subjective parameters for driveability and acoustics, AVL has developed dedicated tools and methods to quantify these attributes with high maturity.In terms of acoustics and NVH there are several crucial noise sources within electrified powertrains, which have to be treated with high attention from the initial development phase to avoid any kind of unforeseen annoyances: E-motor with inverter, transmission and secondary drive are most relevant. This issue becomes even more important with the ongoing market trend of products featuring increased power.Electrified motorcycles commonly are expected to offer supreme acceleration performance, but even this attribute may lead into driver's disappointment if throttle response and overall vehicle driveability parameters are inhomogeneous. The driveability and the…
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Acoustic Study on Motorcycle Helmets with Application of Novel Porous Material

AcouTech Lab, Dept of Mechanical and Industrial Engineering,-Jüri Lavrentjev, Hans Rämmal
  • Technical Paper
  • 2019-32-0531
To be published on 2020-01-24 by Society of Automotive Engineers of Japan in Japan
A critically high noise level inside protective helmet is a prevalent concern for motorcyclists. Especially at highway speeds where the noise level, regardless of helmet type can exceed 100 dB(A) and approaches threshold of discomfort, often resulting in temporary hearing loss. Despite of large share of persons exposed to such noise disturbance around the world, the in helmet noise levels have not significantly decreased over the last decades. Only few scientific publications can be found to systematically address this issue. Furthermore, in respect of driving safety even moderate noise levels are reported to impair reaction times and reduce attention of motorcyclists. At higher speeds the dominant helmet noise source is linked to aerodynamic turbulence around the helmet shell. The loudness and spectral contents mainly depend on the driving speed, windscreen configuration, riding position and helmet geometry. In this paper a series of on-road tests and laboratory experiments with three main types of helmets (“full face”, “flip up” and “open face” type) have been performed with the focus on in-helmet acoustics. Noise spectra at the location…
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Band gaps and torsional vibration in a periodic shaft

EATON Ltda.,-André L. A. M. Leão
University of Campinas-J. R. F. Arruda
  • Technical Paper
  • 2019-36-0224
Published 2020-01-13 by SAE International in United States
Shafts used in torque and angular velocity transmission may behave as torsional vibration amplifiers due to resonance followed by unwanted vibrations. Many technologies are applied to attenuate vibration in certain frequency ranges in automotive, aerospace and industrial applications. More recently, using the concept of periodic structures (phononic crystals and metamaterials), it has been shown to be possible to obtain frequency band gaps where elastic waves cannot propagate and, therefore, standing waves cannot build up, thus avoiding resonance. Using a few periodic cells large attenuation can be obtained, so that the structure behaves like a mechanical filter. Investigations in periodic structure dynamics have been developed in recent years aiming at to attenuating specific and wide frequency ranges. The periodic structure can be a combination of different materials, or a unique material varying the geometry periodically. This work explores the possibility of using periodic shaft structures to create torsional band gaps for torsional vibration attenuation. Theoretical models and experimental results for torsional vibrations in a periodic shaft are investigated. The approach is to build a dynamic model…
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Independent Aftermarket (IAM) and the Three Dimensions of Friction Material Evaluation

LINK South America-Pedro Oliveira, Henrique Rodrigues, Eduardo Ferro
  • Technical Paper
  • 2019-36-0006
Published 2020-01-13 by SAE International in United States
It is well known the difference between development levels and engineering investment applied to passenger car brake pads when compared to Original Equipment Manufacturer (OEM) and items sold in the Independent Aftermarket (IAM). Based on these differences, the objective of this paper is to propose a simple evaluation for the IAM that can provide at least some level of the understanding of frictional material behavior. Based on a tripod of variables, or three Dimensions Development, described in this work as Performance, Comfort (NVH) and Durability; and using internationally and established testing procedures to measure these dimensions in order to meet the IAM demands for the cost-benefit engineering investment. An important part of the proposed tool is to position friction material against competition for market known issues, and, more importantly, to ensure end product safety and reliability.
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Brake noise analysis on tractive axle of 6x2 tractor vehicle

CNHI - Iveco Latin America / UFMG – Programa de Pós-Graduaçã-Rafael Fortuna Pizzi
CNHI – Iveco Latin America-Getúlio Soares Júnior
  • Technical Paper
  • 2019-36-0008
Published 2020-01-13 by SAE International in United States
This study aims at analyzing the causes of noise in a heavy vehicle brake system (6x2 tractor) and proposing solutions to improve comfort during braking as it is known that, during the activation of the automotive brakes, noise can be generated in different frequency bands that can cause discomfort to the user and the study of how to reduce it is considerably important to bring more comfort in its use. As a working methodology, firstly, comparative analysis of dimension and material were performed between the axle assembly that presented noise and another axle assembly of a vehicle with no noise adopted as reference. This information was used as the basis for the frequency and acceleration virtual analysis that were validated with vehicle instrumentation and data acquisition. In parallel, vehicle tests with different brake friction materials were conducted. The answers of the dimension and material analysis from the axles assemblies highlighted the specificities of each of them but did not show great influence in the observed noise incidence. The vehicle instrumentation and data acquisition besides validate…
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