Study on Energy Spectrum Instability in the Processes of Propagating and Breaking of Focusing Waves

摘要: Based on phase focusing theory, waves with different spectral types and breaking severities were generated in a wave flume. The time series of surface elevation fluctuation along the flume obtained by utilizing 22 probes mounted mid-stream spectrum using fast Fourier transform (FFT), instability characteristics energy reported this paper. By analyzing variation total energy, after was found to clearly decrease, loss value ratio gradually increased tended stabilize enhancement severity for types. When occurred, primarily high-frequency range f/fp>1.0, gain low-frequency f/fp<1.0. As increased, gain-loss decreased gradually, which demonstrates that mostly dissipated. For plunging waves, reached 24% constant steepness (CWS) spectrum, slightly larger at approximately 30% amplitude (CWA) largest 42% Pierson-Moskowitz (PM) spectrum.