Development of Prediction Method for Wind Noise Caused by Airflow Around Front Pillar

2011 ◽  
Author(s):  
Yasuhiko Okutsu ◽  
Naoki Hamamoto ◽  
Robert Powell ◽  
Long Wu
Keyword(s):  
High Frequency ◽  
Noise Level ◽  
High Speed ◽  
Prediction Method ◽  
Noise Sources ◽  
Wind Noise ◽  
Front Passenger ◽  
Passenger Seat ◽  
Simulation Results ◽  
Head Area

To control high frequency wind noise upper than 1 kHz is important to ensure the comfort for a driver and passengers when vehicles cruise at high speed. Therefore the prediction method for high frequency wind noise inside a cabin has been required for development of a vehicle. This paper describes about the prediction method for high frequency wind noise from numerical simulation results. In this study, wind noise caused by airflow around a front pillar is predicted. We have predicted wind noise by visualizing noise sources and pressure fluctuation on vehicle surfaces in recent years. Although an inferior-to-superior relationship can be predicted from these results, it was difficult to estimate quantitative interior noise level. In this research, the SEA code is examined to predict such noise level. The SEA code has confirmed showing a qualitative and almost quantitative consistency of measured and calculated SPL at the head area of a front passenger seat.

Mechanism of interior noise generation in high-speed vehicle based on anti-noise operational transfer path analysis

2020 ◽  
Vol 235 (1) ◽  
pp. 273-287
Author(s):  
Ningning Liu ◽  
Yuedong Sun ◽  
Yansong Wang ◽  
Pei Sun ◽  
Wenwu Li ◽  
...  
Keyword(s):  
Path Analysis ◽  
High Speed ◽  
Noise Signal ◽  
Interior Noise ◽  
Analysis Model ◽  
Noise Sources ◽  
Wind Noise ◽  
Transfer Path ◽  
Transfer Path Analysis ◽  
Path Analysis Model

Owing to the continuous development of the automobile industry, increasingly stringent performance requirements for noise, vibration, and harshness of automobiles are being presented. Interior noise control in high-speed vehicles has not been adequately addressed, owing to the complex mechanism of noise generation. As simulations performed previously focused on vehicle wind noise and tyre noise cannot adequately predict the effect on passenger ear-side noise, these issues are investigated in this study. Their effects on passengers are investigated using transfer path analysis. An anti-noise operational transfer path analysis is proposed to study noise generated in high-speed vehicles. The established anti-noise operational transfer path analysis model can eliminate crosstalks between noise source signals of different transmission paths. The model is validated by comparing the measured and calculated values of the anti-noise operational transfer path analysis model. The coherence of the input noise signal and the ear-side noise signal of the passenger is assessed using coherence analysis. By calculating and categorising the contributions of different noise sources in different locations and types, the main noise sources affecting passenger comfort are determined. The result indicates that the main noise sources affecting the passenger’s ear-side noise change from engine noise to left-A wind noise and tyre radiation noise with increasing vehicle speed, in which the proportion also increase. The proposed anti-noise operational transfer path analysis is suitable for the interior-noise analysis of high-speed vehicles, and this study may serve as a reference for future studies regarding active and passive noise control in high-speed vehicles.

scholarly journals High-Frequency Core Loss Analysis of High-Speed Flux-Switching Permanent Magnet Machines

Electronics ◽  
2021 ◽  
Vol 10 (9) ◽  
pp. 1076
Author(s):  
Wenfei Yu ◽  
Wei Hua ◽  
Zhiheng Zhang
Keyword(s):  
Permanent Magnet ◽  
Numerical Method ◽  
High Frequency ◽  
High Speed ◽  
Core Loss ◽  
Hysteresis Loops ◽  
Prediction Method ◽  
Element Analysis ◽  
The Core ◽  
Core Losses

Accurate prediction of core losses plays an important role in the design and analysis of flux-switching permanent magnet (FSPM) machines, especially during high-speed and high-frequency operation. Firstly, based on the numerical method, a high-frequency core loss prediction method considering a DC-bias magnetization component and local hysteresis loops as well as the harmonic effect is proposed. Secondly, the magnetizing characteristics of the silicon steel sheet and, consequently, the core loss of the electrical steel used as the core lamination are measured. Then, the loss coefficient of each core loss component is obtained by the data fitting tool. Based on the proposed method, the stator and rotor core losses of a three-phase, 12-stator-slot, and 10-rotor-pole (12/10) FSPM machine with different soft iron materials and driving modes are calculated. Finally, the results of the numerical method are verified by conventional finite element analysis.

Numerical Prediction Method of Resistance Performance of Catamaran Planing Vessels

2013 ◽  
Vol 344 ◽  
pp. 19-22 ◽  
Author(s):  
Hai Long Shen ◽  
Wei Lu ◽  
Yu Min Su
Keyword(s):  
High Speed ◽  
Optimization Design ◽  
Degrees Of Freedom ◽  
Prediction Method ◽  
Hydrodynamic Performance ◽  
Rans Equations ◽  
Six Degrees Of Freedom ◽  
Simulation Results ◽  
Planing Vessel ◽  
Resistance Performance

The classical approaches using CFD software to calculate the hydrodynamic performance of catamaran planing vessel still need to rely on the model test or empirical formula to make sure of the running attitude. So a theoretical calculate method of resistance performance of catamaran planing vessel is proposed in this paper based on RANS equations and the VOF method to couple six degrees of freedom equation of the catamaran planing vessel. Numerical simulation results indicate that using RANS equations can better forecast hydrodynamic performance of catamaran planing vessel at high speed, which provides a practicable numerical method for optimization design of the catamaran planing vessels hull.

High-Speed, High-Frequency and Low-PDP, CNFET Full Adder Cells

2015 ◽  
Vol 24 (09) ◽  
pp. 1550130 ◽  
Author(s):  
Yavar Safaei Mehrabani ◽  
Mohammad Eshghi
Keyword(s):  
Monte Carlo ◽  
High Frequency ◽  
High Speed ◽  
Transient Analysis ◽  
State Of The Art ◽  
Process Variations ◽  
Full Adder ◽  
The Other ◽  
Simulation Results ◽  
Silicon Based

In this paper, three CNT-based full adder designs, called Design1, Design2 and Design3, are proposed. In these designs 12, 14 and 16 transistors are used, respectively. In all designs only 3-input NAND, Majority-not and NOR functions are used. First, a preliminary structure (Design1) is presented using 12 transistors. Then its weaknesses are tackled in two steps. In fact, in each step a new design is presented by adding two more transistors to its predecessor. Therefore two new structures called Design2 and Design3 are built in which Design3 is the most efficient one. To study the performance of Design3 versus other silicon-based and CNT-based 32-nm classical and state-of-the-art cells, comprehensive simulations with regard to various supplies, loads, operating frequencies, and temperatures are performed using Synopsys HSPICE tool. Simulation results confirm that the proposed cell is superior to the other cells. At last the robustness of Design3 against the diameter mismatches of CNTs which is one of the most important concerns of nanoelectronics is studied using Monte Carlo transient analysis. This simulation reveals that Design3 functions very well against manufacturing process variations.

scholarly journals 1212 Analysis on High Frequency Vibration Characteristic of Passenger-Seat in High Speed Railway Vehicle

2011 ◽  
Vol 2011.20 (0) ◽  
pp. 111-114
Author(s):  
Sotaro SAITO ◽  
Ryuzo HAYASHI ◽  
Masao NAGAI ◽  
Ryohei SHIMAMUNE ◽  
Masahiko MIZUGUCHI ◽  
...  
Keyword(s):  
High Frequency ◽  
High Speed ◽  
Railway Vehicle ◽  
Vibration Characteristic ◽  
High Speed Railway ◽  
High Frequency Vibration ◽  
Passenger Seat

A maximum noise-level prediction method for high-speed railways in China: A case study using the Baiyun campus of Guangdong polytechnic normal university

2019 ◽  
Vol 150 ◽  
pp. 124-131 ◽  
Author(s):  
Feng Li ◽  
Mingchuan Wu ◽  
Cong Lai ◽  
Shenchang Chen ◽  
You Xu ◽  
...  
Keyword(s):  
Noise Level ◽  
High Speed ◽  
Prediction Method ◽  
Normal University

CALCULATION OF THE INTEGRAL NOISE LEVEL AT A FIELD POINT OF A FREE SUPERSONIC JET OF A ROCKET ENGINE

Akustika ◽  
2020 ◽  
Vol 36 (36) ◽  
pp. 22-24
Author(s):  
Anatoly Kochergin ◽  
Valeeva Ksenia
Keyword(s):  
Acoustic Field ◽  
Noise Level ◽  
Rocket Engine ◽  
Supersonic Jet ◽  
Noise Sources ◽  
Field Point

The paper considers an acoustic field created by a supersonic jet (CES) of a rocket engine freely flowing into flooded space. The acoustic field was presented in the form of a diagram of noise isobars, from which it can be seen that the acoustic field is formed by two effective noise sources: the nearest one, lying at a distance of 5-10 calibers from the nozzle cut and the far one, lying at a distance of 15-30 calibers from the nozzle cut.

scholarly journals Characterization of Noise Level Inside a Vehicle under Different Conditions

Sensors ◽  
2020 ◽  
Vol 20 (9) ◽  
pp. 2471 ◽  
Author(s):  
Daniel Flor ◽  
Danilo Pena ◽  
Luan Pena ◽  
Vicente A. de Sousa ◽  
Allan Martins
Keyword(s):  
Regression Analysis ◽  
Noise Level ◽  
Acoustic Noise ◽  
Experimental Setup ◽  
Strongly Correlated ◽  
Noise Levels ◽  
Noise Sources ◽  
Statistical Tools ◽  
Window Position

Vehicular acoustic noise evaluations are a concern of researchers due to health and comfort effects on humans and are fundamental for anyone interested in mitigating audio noise. This paper focuses on the evaluation of the noise level inside a vehicle by using statistical tools. First, an experimental setup was developed with microphones and a microcomputer located strategically on the car’s panel, and measurements were carried out with different conditions such as car window position, rain, traffic, and car speed. Regression analysis was performed to evaluate the similarity of the noise level from those conditions. Thus, we were able to discuss the relevance of the variables that contribute to the noise level inside a car. Finally, our results revealed that the car speed is strongly correlated to interior noise levels, suggesting the most relevant noise sources are in the vehicle itself.

scholarly journals Verification of electric steel punching simulation results using microhardness

2021 ◽  
Author(s):  
Sampsa Vili Antero Laakso ◽  
Ugur Aydin ◽  
Peter Krajnik
Keyword(s):  
Plastic Deformation ◽  
High Speed ◽  
Steel Sheet ◽  
Electrical Steel ◽  
High Speed Steel ◽  
Experimental Methods ◽  
Fem Simulations ◽  
Iron Losses ◽  
Simulation Results ◽  
Electrical Steel Sheet

AbstractOne of the most dominant manufacturing methods in the production of electromechanical devices from sheet metal is punching. In punching, the material undergoes plastic deformation and finally fracture. Punching of an electrical steel sheet causes plastic deformation on the edges of the part, which affects the magnetic properties of the material, i.e., increases iron losses in the material, which in turn has a negative effect on the performance of the electromagnetic devices in the final product. Therefore, punching-induced iron losses decrease the energy efficiency of the device. FEM simulations of punching have shown significantly increased plastic deformation on the workpiece edges with increasing tool wear. In order to identify the critical tool wear, after which the iron losses have increased beyond acceptable limits, the simulation results must be verified with experimental methods. The acceptable limits are pushed further in the standards by the International Electrotechnical Commission (IEC). The new standard (IEC TS 60034-30-2:2016) has much stricter limits regarding the energy efficiency of electromechanical machines, with an IE5 class efficiency that exceeds the previous IE4 class (IEC 60034-30-1:2014) requirements by 30%. The simulations are done using Scientific Forming Technologies Corporation Deform, a finite element software for material processing simulations. The electrical steel used is M400-50A, and the tool material is Vanadis 23, a powder-based high-speed steel. Vanadis 23 is a high alloyed powder metallurgical high-speed steel with a high abrasive wear resistance and a high compressive strength. It is suitable for cold work processing like punching. In the existing literature, FEM simulations and experimental methods have been incorporated for investigating the edge deformation properties of sheared surfaces, but there is a research gap in verifying the simulation results with the experimental methods. In this paper, FEM simulation of the punching process is verified using an electrical steel sheet from real production environment and measuring the deformation of the edges using microhardness measurements. The simulations show high plastic deformation 50 μm into the workpiece edge, a result that is shown to be in good agreement with the experimental results.

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