Advanced Materials Research Vols. 452-453

Abstract: Based on 3-d, uncompressible onflow model with steady N-S equation and the k-epsilon double equation, aerodymic characteristics of EMU and windbreaks on bridge under cross wind were studied numerically, the results show: (1) compared to no windbreak, EMU overturning moment was decreased 50% by setting general windbreak , 75% by setting ventilated windbreak; ventilated windbreak’s protective effect on train and pantograph-catenary system is better especially when H≥2.5m ; (2) aerodynamic load on ventilated windbreak is far lower than general windbreak; (3)the higher cross-wind velocity is, the more aerodynamic load decreased when setting ventilated windbreak. Besides, ventilated windbreak’s leak form could significantly reduce bridge’s self gravity and wind load, improve wind break ability and EMU operation safety.

Abstract: Based on a brief introduction to elementary theory of wavelet analysis, the disadvantages of wavelet method and wavelet packet method are given. A new wavelet analysis procedure is proposed for decomposition and reconstruction of measured transient signals. This method can search by specific frequency paths, then overcomes the shortcomings of uniform frequency intervals in pure wavelet analyses and of large computational costs in common wavelet packet analyses. As examples, a signal-noise separation and a weak signal extraction are given to show the effectiveness of the new procedure.