Laboratory Simulation Of Deterministic Waves Based On Second-order Wave Generation Theory

At present,the most commonly used method of studying waves is to observe the phenomenon by simulating waves in the laboratory.In laboratory simulation of waves,the most important thing is the ability to accurately simulate wave,which is of great significance for the study of wave propagation and its action on structure.Now the most commonly used first-order wave making theory is based on the small-amplitude assumption which ignores the high-order boundary conditions,so that undesired spurious free-waves are generated during wave making,which will have certain effects on wave research.The second-order wave making method suppresses the spurious free-wave generated by the first-order wave making method by increasing the displacement of the wave maker,thereby obtaining a higher-order accurate wave elevation.In this paper,based on the original first-order wave-making software,the two-dimensional second-order wave-making software is programmed based on the second-order wave-making theory developed by Sch?ffer.The two-dimensional irregular wave and the focused wave are generated in physical and numerical flumes.The validity of the second-order method for irregular and focused wave generation is verified.The second-order wave making method can effectively suppress spurious free-wave and obtain more accurate spectral distribution and wave elevation in both physical and numerical flume.The problems encountered in wave generation by second-order wave-making theory are explained and discussed,which can be used for reference in practical application.In addition,this paper also performs time domain simulations on known or specific two-dimensional wave elevation.The first and second order wave-making methods are used to compare the accuracy of the wave train obtained by the two methods,and the error coefficients of the measured wave elevation and the expected wave train are analyzed.The relevant experiments and discussions on the revised program are also carried out.Finally,the problems encountered in the application of the program are explained and discussed for reference in practical application.