关键词: 近海模拟, 改进JONSWAP谱, 方形-方形细分法, 阈值滤尖峰算法

Abstract: With the problem of normal JONSWAP spectrum unsuitable for offshore wave simulation, an improved JONSWAP spectrum is proposed, which added a depth factor based on study of the relationship between waveform parameters and water depth. Through analyzing the traditional wave fractal algorithm, it is found that large span of information transfer between adjacent interpolation points is the key reason of wave creases and spikes phenomenon. Therefore, a new threshold peak filtering algorithm using square -square fractal is proposed. The results of simulation experiment with OpenGL show that the improved JONSWAP spectrum is suitable for offshore wave simulation, which can generate realistic, smooth, soft shallow waves. The new fractal algorithm can effectively reduce the wave creases and spikes phenomenon. It has a good sense of reality and real-time, and can reach the purpose of shallow offshore simulation in real-time.

Key words: offshore simulation, improved JONSWAP spectrum, square-square segment method, threshold peak filtering algorithm