JOURNAL BROWSE
Search
Advanced SearchSearch Tips
An Analysis of the Flow Field and Radiation Acoustic Field of Centrifugal Fan with Wedge -The Prediction of the Scattered Sound Field-
facebook(new window)  Pirnt(new window) E-mail(new window) Excel Download
 Title & Authors
An Analysis of the Flow Field and Radiation Acoustic Field of Centrifugal Fan with Wedge -The Prediction of the Scattered Sound Field-
Lee, Deok-Ju; Jeon, Wan-Ho;
  PDF(new window)
 Abstract
The objective of this study is to understand the generation mechanism of sound and to develop a prediction method for the acoustic pressure field of a centrifugal fan. If the fan is operating at the free field without the casing, the acoustic analogy is a good method to predict the acoustic of the fan. But, the casing gives a dominant effect to the radiated sound field and the scattering effect of casing should be considered. So, in this paper the Kirchhoff-BEM is developed, which can consider the scattering effect of the rigid body. In order to consider the scattering and diffraction effects owing to the casing, BEM is introduced. The source of BEM is newly developed, so the sound field of the centrifugal fan can be obtained. In order to compare the predicted one with experimental data, a centrifugal impeller and a wedge are used in the numerical calculation and the results are compared with the experimental data. Reasonable results are obtained not only for the peak frequencies but also for the amplitudes of the tonal sound. The radiated acoustic field shows the diffraction and scattering effects of the wedge clearly.
 Keywords
Centrifugal Fan;Boundary Element Method;Acoustic Source;Kirchhoff Surface;Helmholtz Integral Equation;
 Language
Korean
 Cited by
 References
1.
Gutin, L., 1948, 'On the Sound Field of a Rotating Airscrew,' English Translation NACA TM No. TM1195

2.
Lohmann, D., 1992, 'Prediction of Ducted Radiator Fan Aeroacoustics with a Lifting Surface Method,' DGLR/AIAA 92-02-098

3.
Wan Ho Jeon, Duck Joo Lee, 1999, 'An Analysis of the Flow and Sound Field of a Centrifugal Fan Located Near a Wedge,' 5th AIAA/CEAS Aeroacoustics Conference, 99-1830

4.
Seybert, A. F., Soenako, B.,Rizzo, F. J. and Shippy, D. J., 1985, 'An Advanced Computational Method for Radiation and Scattering of Acoustic Waves in Three Dimension,' Journal of Acoustical Society of America, Vol. 77, pp. 362-368 crossref(new window)

5.
이강덕, 이덕주, 1997, '일반경계조건을 가진 얇은 물체에 대한 직접경계요소법의 개발', 한국소음징동공학회지, Vol.7,No.6, pp. 975-984

6.
Martinez, R., 1991, 'The thin-shape breakdown (TSB) of the Helmholtz integral equation,' Journal of Acoustical Society of America, Vol. 90, No. 5, pp. 2728-2738 crossref(new window)

7.
Schenck, H. A., 1968, 'Improved Integral Formulation for Acoustic Radiation Problems,' Journal of Acoustical Society of America, Vol. 44, pp. 41-58 crossref(new window)

8.
Malbequi, P., Candel, S. M. and Eric Rignot, 1987, 'Boundary Integral Calculations of Scattered Fields : Application to a Spacecraft Launcher,' Journal of Acoustical Society of America, Vol. 82, pp. 1771-1781 crossref(new window)

9.
Weidemwnn, J., 1971, 'Analysis og the Relation Between Acoustic and Aerodynamic Parameters for a Series of Dimensionally Similar Centrifugal Fan Rotors,' NASA TT F-13,798