WR-NOISE is a program which calculates the wayside noise generated by a railroad wheel rolling on a straight track.
The successive stages are :
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the roughness of the surfaces in contact produces a vertical displacement at the wheel/rail contact.This displacement is characterized by the load/velocity relation imposed by wheel and rail vertical mechanical impedances;
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that displacement induces vertical and transversal responses in the wheel and rail, corresponding to their mechanical impedances.And the vertical response of the rail induces transmission of vibrations to the ties and, if necessary, to the girder if the track lies on an elevated structure;
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the responses of all these elements (wheel, rail, tie and girder) generate acoustic radiation which, finally, through the contact area filter and the radiation efficiencies, produces the wayside noise.
As output of WR-NOISE, the program plots all physical quantities that appear in the model:
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roughness data;
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wheel and rail impedances and admittances;
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contact area filter attenuation;
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radiation efficiencies of all elements;
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radiated acoustic powers of all elements and total radiated acoustic power;
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average spectral vertical and horizontal velocities of wheel and rail;
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sound pressure levels at distance d of the track;
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rail acceleration;
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coupling factor between tie and girder;
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rail-sleeper transfer function;
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rail loss factor.
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