tailieunhanh - Orthogonal-based wavelet analysis of wind turbulence and correlation between turbulence and forces

This paper will apply the orthogonal-based wavelet decomposition to investigate the intermittency of the turbulence and to detect the turbulence-force correlation in the both temporal-spectral information using proposed cross energy of wavelet decompositions. Analyzing data have been obtained by physical measurements on model from the wind tunnel tests. | Vietnam Journal of Mechanics, VAST, Vol. 29, No. 2 (2007), pp. 73-82 ORTHOGONAL-BASED WAVELET ANALYSIS OF WIND TURBULENCE AND CORRELATION BETWEEN TURBULENCE AND FORCES LE THAI HOA Wind Engineering Laboratory, Graduate School of Engineering, Kyoto University, Japan NGUYEN DONG ANH Institute of Mechanics, Vietnamese Academy of Science and Technology, Vietnam Abstract. Recent models of wind turbulence and turbulence-force relation as well still contain uncertainties. Further studies on them are needed to gain the better knowledge to refine the existing problems from analytical computations to wind tunnel's physical simulations in the wind engineering. The continuous and discrete wavelet transforms have been applied as powerful transformation tools to represent time series into the time•frequency localization. This paper will apply the orthogonal-based wavelet decomposition to investigate the intermittency of the turbulence and to detect the turbulence-force correlation in the both temporal-spectral information using proposed cross energy of wavelet decompositions. Analyzing data have been obtained by physical measurements on model from the wind tunnel tests. 1. INTRODUCTION Uncertainty exists in the recent models of wind turbulence and turbulent-induced forces to produce overestimation or underestimation of random aerodynamic response of structures. It is assumed that the induced forces are proportional to the instantaneous fluctuating velocities (turbulent components) and the attacked direction of turbulent flow as content of the quasi-steady theory. This theory is consistent, howeveP, only if t here are simultaneous correspondences between turbulence and turbulent-induced forces not in the frequency domain, but the time domain. So far, moreover, turbulence and induced forces has usually been studied based on the spectral transformation that is only valid for stationary time series. Wavelet Transforms (WT) have been recently developed as mathematical tools, .