Influence of web plate holes on the radiation noise characteristics of wheels of the high speed train

Abstract

The finite element model of wheels without holes was established to compute its free modal and compare with the experimental result. The relative error was controlled within 5 %, which indicated that the finite element model in this paper was reliable. Based on the finite element and geometric model, the acoustic boundary element model of wheels was established to compute the radiation noise of wheels under the action of radial and normal excitation forces. Results showed that the change trend and value of radiation noises of wheels were similar under the action of two kinds of excitation forces when the analyzed frequency was lower than 1421 Hz. However, the radiation noise of wheels under the action of two kinds of excitation forces was significantly different and presented obvious directivity in three planes with the increase of the analyzed frequency. Then, models of wheels with 5, 6, 9 and ellipse holes were established to compute radiation noises and conduct comparative analysis. Results showed that the radiation noise of wheels with 6 holes was relatively minimum under radial and normal excitations and did not decrease with the increase of the hole number. The radiation noise of wheels with circular holes made certain improvement, compared with the radiation noise of wheels with ellipse holes. Distribution curves for the directivity of radiation noises of various wheels were highly symmetrical in the plane and radiation noises had relatively maximum in the position of multiples of 30°. The curve for the directivity of radiation noises of wheels with 5 holes was clearly different from that of other structures in the plane.

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“…This short circuiting is observed in [172][173][174], where perforated pattern is seen to have a considerable effect on acoustic radiation in baffled and unbaffled plates, with the number and size of the holes having a determinant effect. Later, Tong et al predict a 2 dB reduction of wheel radiation in a parametric study using different numbers of circular or elliptic holes with the use of BEM [175]. In [171] a quieter wheel with a 6 -9 dB improvement in the range below 1000 Hz is conjectured when holes are applied.…”