A design method of fairing acoustic noise mitigation for Korean space launcher

2016 ◽  
Vol 140 (4) ◽  
pp. 3042-3042
Author(s):  
Soon-Hong Park ◽  
Sang-Hyun Seo
Keyword(s):  
Acoustic Noise ◽  
Design Method ◽  
Noise Mitigation ◽  
Space Launcher

scholarly journals POSSIBILITIES OF RAILWAY DEVELOPMENT IN LITHUANIA: THE ANALYSIS OF REGULATIONS FOR RAILWAY DESIGN IN THE ASPECT OF REDUCTION OF ACOUSTIC NOISE / GELEŽINKELIŲ PLĖTROS GALIMYBĖS LIETUVOJE: GELEŽINKELIŲ KELIAMS PROJEKTUOTI SKIRTŲ NORMINIŲ TECHNINIŲ DOKUMENTŲ

2016 ◽  
Vol 7 (5) ◽  
pp. 557-563 ◽  
Author(s):  
Aja Tumavičė ◽  
Alfredas Laurinavičius
Keyword(s):  
Acoustic Noise ◽  
Development Planning ◽  
Mitigation Measures ◽  
Noise Emission ◽  
Noise Mitigation ◽  
Planning Stage ◽  
Railway Infrastructure ◽  
The World ◽  
Problematic Issue

All over the world railways are of the least-polluting vehicles, and they became increasingly popular. However, the noise emission from railway infrastructure is the most problematic issue, especially at the development planning stage. This article presents analysis of Lithuanian regulations for railway design in the aspect of reduction of acoustic noise. It analyses regulations, which are mandatory for Lithuanian railway designers and builders. In addition, the overview of regulations’provisions, which are related to noise mitigation measures, are presented. Pasaulyje vis labiau populiarėja kelionės geležinkeliais, kurie yra viena iš mažiausiai taršių transporto priemonių. Nuo geležinkelio infrastruktūros sklindantis triukšmas yra viena didžiausių problemų, ypač planuojant jų plėtrą. Straipsnyje pristatyta Lietuvos norminių techninių dokumentų, skirtų geležinkeliams projektuoti, analizė akustinio triukšmo mažinimo aspektu. Buvo išanalizuoti norminiai techniniai dokumentai, kurie privalomi naudoti Lietuvoje geležinkelių projektuotojams ir geležinkelių tiesėjams, bei apžvelgta, kokios yra juose nuostatos, susijusios su triukšmą mažinančiomis priemonėmis.

Acoustic Noise Mitigation of Switched Reluctance Machines with Windows on Stator and Rotor Poles

2020 ◽  
pp. 1-1 ◽  
Author(s):  
Omer Gundogmus ◽  
Mohammed Elamin ◽  
Yusuf Yasa ◽  
Tausif Husain ◽  
Yilmaz Sozer ◽  
...  
Keyword(s):  
Acoustic Noise ◽  
Noise Mitigation ◽  
Switched Reluctance ◽  
Switched Reluctance Machines ◽  
Rotor Poles

scholarly journals A Structure Design Method for Reduction of MRI Acoustic Noise

2017 ◽  
Vol 2017 ◽  
pp. 1-12
Author(s):  
Jiaofen Nan ◽  
Nannan Zong ◽  
Qiqiang Chen ◽  
Liangliang Zhang ◽  
Qian Zheng ◽  
...  
Keyword(s):  
Noise Reduction ◽  
Acoustic Noise ◽  
Design Method ◽  
Structure Design ◽  
Gradient Coil ◽  
Resonance Imaging ◽  
Resonant Modes ◽  
Reduction Methods ◽  
Main Magnet ◽  
Asymmetric Configuration

The acoustic problem of the split gradient coil is one challenge in a Magnetic Resonance Imaging and Linear Accelerator (MRI-LINAC) system. In this paper, we aimed to develop a scheme to reduce the acoustic noise of the split gradient coil. First, a split gradient assembly with an asymmetric configuration was designed to avoid vibration in same resonant modes for the two assembly cylinders. Next, the outer ends of the split main magnet were constructed using horn structures, which can distribute the acoustic field away from patient region. Finally, a finite element method (FEM) was used to quantitatively evaluate the effectiveness of the above acoustic noise reduction scheme. Simulation results found that the noise could be maximally reduced by 6.9 dB and 5.6 dB inside and outside the central gap of the split MRI system, respectively, by increasing the length of one gradient assembly cylinder by 20 cm. The optimized horn length was observed to be 55 cm, which could reduce noise by up to 7.4 dB and 5.4 dB inside and outside the central gap, respectively. The proposed design could effectively reduce the acoustic noise without any influence on the application of other noise reduction methods.

Aero-Acoustic Design of Fan Using Inverse Method

2003 ◽  
Author(s):  
S. Lee ◽  
H.-J. Kim ◽  
W.-S. Song ◽  
K.-W. Ahn
Keyword(s):  
Acoustic Noise ◽  
Design Method ◽  
Low Noise ◽  
Inverse Design ◽  
Experimental Result ◽  
Phase System ◽  
Blade Loading ◽  
Acoustic Performance ◽  
Inverse Design Method ◽  
Line Analysis

A multi-dimensional inverse algorithm was developed to design low noise fan. In this approach, mean-line analysis, 3-D CAD, automatic grid generation method, and CFD solver can be integrated with aero-acoustic inverse design method. The overall sound pressure level distributions obtained from specified sets of unsteady blade loading distribution serve input data to the multi-dimensional acoustic inverse module, and may be used to design optimal geometry to satisfy the aerodynamic and aero-acoustic performance. To execute an effective inversion of non-minimum phase system, SVD is introduced. With the inverse design concept used in the developed software, the design phase of an optimal blade geometry, which yields a required aerodynamic performance with minimal acoustic noise, may be significantly shortened. The experimental result of prototype fans, designed by using this software, showed that the aerodynamic and aero-acoustic performance is reasonably well predicted.

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