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Numerical Prediction and Verification of Noise Radiation Characteristics of Diesel Engine Block

Deere & Company-Sanghoon Suh
John Deere Technology Center India-Devendra Mandke, Deepak Ghaisas, Sachin Pawar
Published 2019-06-05 by SAE International in United States
To assess the contribution of structure-borne noise from an engine, it is critical to characterize the dynamic and vibro-acoustic properties of the engine components and assembly. In this paper, a component level study of a three-cylinder diesel engine block is presented. Virtual analysis was done to predict the natural frequencies and mode shapes of an engine block in the first step. Then, these results were used to decide the optimum test locations and an experimental modal test was conducted on the engine block. The initial virtual model results for the natural frequencies and mode shapes were correlated with the results from test. Then, the virtual model was updated with the damping derived from experimental modal test to match the vibration frequency response functions. Further, the virtual model was used for prediction of vibro-acoustic transfer functions. The vibro-acoustic transfer functions were also obtained from test. The results of transfer function were correlated with the test. In future, we plan to use this approach for prediction of the vibration and vibro-acoustic transfer functions for sub-assembly and eventually…
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Power Electronic Noise-Simulation Measurement Comparison

AVL LIST GmbH-Markus Resch, Thomas Resch, Stephan Brandl
AVL Software and Functions Gmbh-Peter Olbrich, Hartwig Reindl
Published 2019-06-05 by SAE International in United States
A growing development of hybrid or fully electrical drives increases the demand for an accurate prediction of noise and vibration characteristics of electric and electronic components. This paper describes the numerical and experimental investigation of noise emissions from power electronics, as one of the new important noise sources in electric vehicles.The noise emitted from the printed circuit board (PCB) equipped with multi-layer ceramic capacitors (MLCC) is measured and used for the calibration and validation of numerical model. Material properties are tuned using results from experimental modal analysis, with special attention to the orthotropic characteristic of the PCB glass-reinforced epoxy laminate sheet (FR-4). Electroacoustic excitation is pre-calculated using an extension of schematic-based EMC simulation and applied to the structural model. Structural vibrations are calculated with a commercial FEM solver with the modal frequency response analysis. Sound radiation is simulated using the wave-based approach (WBT). Simulation and experimental results are compared in a frequency range up to 10 kHz.The developed simulation methodology can successfully identify the main noise sources from the equipped PCB. Critical peak noise responses…
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Determining Vibro-Acoustic Characteristics and Structural Damping of an Elastic Monolithic Panel

Shiloh Industries, Inc.-Antonio Figueroa
Wayne State University-Sean Wu, Lingguang Chen
Published 2019-06-05 by SAE International in United States
Evaluations of the dynamic and acoustic responses of panels, partitions, and walls are of concern across many industries, from building home appliances, planning meeting rooms, to designing airplanes and passenger cars. Over the past few decades, search efforts for developing new methodologies and technologies to enable NVH engineers to acquire and correlate dynamically the relationship between input excitations and vibro-acoustic responses of arbitrary-shaped panels has grown exponentially. The application of a particular methodology or technology to the evaluation of a specific structure depends intimately on the goals and objectives of the NVH engineers and industries. In this work, we present the comparisons between the traditional modal analyses for structural vibrations together with sound intensity measurements of sound radiation and a laser-assisted Helmholtz equation least squares (HELS) method [1, 2, 3, 4] to characterize the dynamic and acoustic responses of an arbitrarily shaped structure subject to non-contact acoustic excitations. Input data for the latter include the normal surface velocities measured at a finite number of points on the surface of the structure that are accessible to…
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Electrical Characterization of Crystalline UO2, THO2 and U0.71TH0.29O2

  • Magazine Article
  • TBMG-34527
Published 2019-06-01 by Tech Briefs Media Group in United States

Tracking and identifying radiation sources in the age of nuclear proliferation and well- resourced non-state actors is a national priority. Current neutron detection methods favor large detector volumes and long data collection times. Additionally, portable neutron detection methods have persistent problems with low signal-to-noise (small pulse height) and require large applied voltages.

 
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Electrical Characterization of Crystalline UO2, THO2 and U0.71TH0.29O2

Aerospace & Defense Technology: June 2019

  • Magazine Article
  • 19AERP06_08
Published 2019-06-01 by SAE International in United States

Evaluating the suitability of advanced alloys for use in uranium-based neutron detectors.

Tracking and identifying radiation sources in the age of nuclear proliferation and well-resourced non-state actors is a national priority. Current neutron detection methods favor large detector volumes and long data collection times. Additionally, portable neutron detection methods have persistent problems with low signal-to-noise (small pulse height) and require large applied voltages.

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Measurement Method for Radioactive Methane

  • Magazine Article
  • TBMG-34384
Published 2019-05-01 by Tech Briefs Media Group in United States

Anew method for measuring radioactive methane is an optical one based on spectroscopy. Previously, radioactive methane has been measured with accelerator mass spectrometry involving expensive machines. Optical measuring could be a cheaper and more agile method.

 

Test Procedure for Determining the Resistance of Safety-Glazing Materials, of which One Surface is Plastic, to Simulated Weathering

Glazing Materials Standards Committee
  • Ground Vehicle Standard
  • J2081_201904
  • Current
Published 2019-04-11 by SAE International in United States
This SAE Recommended Practice determines whether plastic and glass-plastic safety glazing materials will successfully withstand exposure to simulated weathering conditions.
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Generation and Oxidation of Soot due to Fuel Films Utilizing High Speed Visualization Techniques

Continental Automotive France-Jerome Helie
Continental Automotive Systems-William Imoehl
Published 2019-04-02 by SAE International in United States
For a better understanding of how soot is generated due to fuel films, a constant volume vessel was used together with four visualization techniques due to their high spatial (2D) and time resolution: Schlieren, natural luminosity, diffused back illumination and OH* chemiluminescence. The analysis was performed keeping the injection pressure at 30 bar and changing the plate temperature on which the spray impacts: 80, 120, 160 and 200 °C. The fuel is a mixture of iso-octane, hexane, toluene and 1-methylnaphthalene, which presents similar properties to commercial gasoline. Valuable insights were gained from the results that infer the real nature of the radiation observed during combustion events in gasoline direct injection (GDI) engines due to the presence of a fuel films which are conventionally described as “pool fires”. The results show that the highest quantity of soot is generated between plate temperatures of 80 and 120 °C. The composition of the fuel film and the flow field generated after the passage of the flame front are of paramount importance in the description of the soot generated…
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A Research on Vehicle Gearbox Whine Based on Multi-Physics Coupling Simulation and Psychoacoustics

Jiangxi Jiangling Chassis Co., Ltd.-Sicheng Tang, Yong Xu
Published 2019-04-02 by SAE International in United States
Vehicle gearbox whine is a common NVH problem which may directly cause complains from passengers on the quality and performance of vehicle. In order to efficiently and fundamentally control the whine phenomenon, this work first studied the characteristics and mechanisms of the gearbox vibration and noise. The study results revealed that the transmission error of gear was the excitation source of gearbox vibration, and the ambient air was the main transfer path of radiation noise. Then a multi-physics coupling simulation model was built to reveal the interactions among gear, housing and ambient air. This model could also predict the characteristics of the sound field near the passenger’s ear. To take account the psychoacoustic property of human auditory system, this work applied a quality index called tonality to evaluate the severity of gearbox whine. This paper also describes a case study to verify the accuracy and availability of the simulation model. In this case, the whine phenomenon of a practical gearbox was simulated with the proposed model first, and then an optimization on the micro geometry…
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Evaluation of Equivalent Temperature in a Vehicle Cabin with a Numerical Thermal Manikin (Part 1): Measurement of Equivalent Temperature in a Vehicle Cabin and Development of a Numerical Thermal Manikin

AGC Inc.-Yoshiichi Ozeki, Seiko Suzuki
Nissan Motor Co., Ltd.-Hajime Oi, Yasushi Ichikawa, Akira Matsumoto, Fusaaki Takeo
Published 2019-04-02 by SAE International in United States
The present paper is Part 1 of two consecutive studies. Part 1 describes three subjects: definition of the equivalent temperature (teq), measurements of teq using a clothed thermal manikin in a vehicle cabin, and modeling of the clothed thermal manikin for teq simulation. After defining teq, a method for measuring teq with a clothed thermal manikin was examined. Two techniques were proposed in this study: the definition of “the total heat transfer coefficient between the skin surface and the environment in a standard environment (hcal)” based on the thermal insulation of clothing (Icl), and a method of measuring Icl in consideration of the area factor (fcl), which indicates the ratio of the clothing surface to the manikin surface area. Then, teq was measured in an actual vehicle cabin by the proposed method under two conditions: a summer cooling condition with solar radiation and a winter heating condition without solar radiation. The results showed that teq, including the effects of the air temperature, air velocity and thermal radiation, was measured properly. Subsequently, a numerical thermal manikin…
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