Large Eddy Simulation and Hilbert Huang Transform for fluctuation pressure of high speed train

Abstract

Fluctuation pressure acting on the surface of high speed trains is the main source of aerodynamic noise. Therefore, it becomes very important to research components of the fluctuation pressure for controlling the aerodynamic noise. In this paper, Large Eddy Simulation (LES) method is applied to calculate the fluctuation pressure acting on a certain type of CRH high speed train and the distribution rule of the fluctuation pressure is studied by Hilbert Huang Transform (HHT) method. Both the fluctuating part and the average part from the surface pressure are extracted by Empirical Mode Decomposition (EMD). A comparison of the distribution rules for fluctuation pressure at two different speed levels is made.

The simulation study of three typical time frequency analysis methods

“…The recognition, feature extraction and monitoring analysis and other technologies of variety of physiological signals including EEG signal has become a hot topic of research in recent years [1]. All kinds of analysis methods such as Fourier transformation [2][3][4], Short Time Fourier transformation [5][6][7],wavelet and wavelet package transformation [8][9][10][11][12], Hilbert-Huang Transformation (HHT) [13][14][15][16][17] and other technologies have been applied to analysis of signal. Fourier transformation is the basic of analysis of time domain and frequency domain for signal, and is very valid to the analysis of periodic stable signal.…”