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Developing Assumptions for the Tram Noise Attenuation Passive System Using the Noise Maps Analysis Method

Nowakowski Tomasz, Firlik Bartosz, Staśkiewicz Tomasz

Archives of Acoustics

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2019

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Vol. 44, No. 4

783--792

EN

The paper presents experimental research carried out to determine the possible actions to reduce the noise generated by trams in a highly urbanised area. A few design strategies affecting tram ride quality have been presented – especially in the aspect of the acoustic phenomena. Main sources of the noise in trams were characterised. The paper includes selected results of comprehensive studies of tram noise in the pass-by test based on the authors’ research methodology. The tests were carried out on various types of trams to recognise the acoustic phenomena characteristic for the rolling stock in a selected tram system. The results of the measurements were analysed both in the field of amplitudes based on noise maps and in respect to frequencies based on noise spectra. The results indicated the rolling noise as important issue demanding taking some actions in order to reduce its level. In this area, elements for the application of individual attenuation solutions, i.e. at the source and during propagation, were presented. The results of the measurements were used as input data to the assumptions of the noise attenuation passive system, which was the final outcome of the study. Dedicated external dampers were used in the case of wheel and rail pairs, where the dominant power of the noise is emitted. The acoustic properties of the bogie area and the bogie side covers were redeveloped to hamper the noise propagation, which is a novel application. The presented results indicate measurable benefits from the applied solutions on the tram noise reduction.

2

Parametryzacja i ocena hałasu pisków od krzywizn i hamowania podczas dojazdu pociągu do stacji

Wszołek T., Koter M.

Przegląd Mechaniczny

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2015

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nr 7-8

38--42

PL

Dominującym źródłem hałasu kolejowego w przeważającym zakresie prędkości jest hałas toczenia wywołany drganiami kół i szyn spowodowanymi drganiami powstającymi na styku koło/szyna. Hałas toczenia ma charakter szerokopasmowy o narastającym udziale wyższych częstotliwości wraz ze wzrostem prędkości pociągów. Ale piski na krzywiznach są jednymi z najgłośniejszych i najbardziej dokuczliwych źródeł hałasu od linii kolejowych metra i tramwajów. Są one również spowodowane interakcją pomiędzy kotem a szyną, ale mają zupełnie inny charakter Są silnie tonalne i występują w ostrych łukach, a powodowane są drganiami kota w jednym z jego rezonansów. Można tu rozróżnić piski spowodowane ocieraniem bocznej i górnej części szyny, jak również piski od ocierania kołnierza. Podobnym zjawiskiem jest pisk hamulców, który jest emitowany w czasie hamowania.

EN

The most important source of noise from railways at most speeds is a rolling noise caused by wheel and rail vibrations induced at the wheel/rail contact. The rolling noise is fairly broad-band in nature, the relative importance of higher frequency components increasing as the train speed increases. But the curve squeal is one of the loudest and most disturbing noise sources from railways metros and tramways. It is also caused by interaction between wheel and rail but bas a quite different character. It is a strongly tonal noise occurring in sharp curves, being associated with vibration of the wheel in one of its resonances. It is also necessary to distinguish between the squeal caused by lateral creepage, top of rail squeal as well as flange squeal. A similar phenomenon is a brake squeal which is emitted during braking.

3

Dynamics of Rolling Wheels

Nackenhorst U., Brinkmeier M., Ziefle M.

Machine Dynamics Problems

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2006

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Vol. 30, No. 1

45-60

EN

A finite element approach for the simulation of rolling tire dynamics is presented. As a key for the efficient numerical solution an arbitrary Lagrangian Eulerian kinematics description is introduced. After a short introduction into the general theory one focus is laid onto the computation of stationary rolling contact. Here a novel approach for the treatment of inelastic material properties by a discontinuous Galerkin discretization of the advection problem is presented. In the continuation the analysis of transient dynamic aspects with emphasis to rolling noise prediction is discussed. A modal superposition approach is suggested, where special attention is laid onto the numerical solution of the related non-symmetric and complex valued eigenproblems for the gyroscopic system. Numerical examples on detailed tire-models demonstrate the applicability of the presented theory.