Water Surface Elevation Recovery from Wave Pressure Signals

• Main Authors: Tang, Shih-Tse, 唐世澤
• Other Authors: Yi-Yu Kuo, Yung-Fang Chiu
• Format: Others
• Language: zh-TW
• Published: 1996
• Online Access: http://ndltd.ncl.edu.tw/handle/32610434592276746584

碩士 === 國立交通大學 === 土木工程學系 === 84 === In the present study an empirical transfer function between the wave pressure and wave height,which was established by Kuo and Chiu(1994) ,was applied to predict the history signals of the free water surface elevation from the wave pressure beneath the still water level.The Fast Fourier Transform(FFT) method is used to calculate the power spectral and history signals of wave height.The FFT method is compared with LCM method developed by Nielsen(1986) in this paper.It is found that both of FFT method and LCM method are accurately calculated when the pressure gages are locatted near the still water level.However, when the distance between the pressure gage and the still water level is longer,the FFT method with the empirical transfer function is more efficient and accurate than the LCM method. Furtherwore,the present study has decided on the cutoff frequency range,the weak point of the power spectral analisis which was resolved in this paper. Furthermore,the present study used the physical model test to investigate the transfer function between the wave pressure and the wave height in shallow water. By the analysis from the experimental data, we can find the transfer function is concern with the wave frequency and pressure gage locations. In addition ,the transfer functions of each older nonlinear components seem to be the same.