Active Absorbing Wave Generator In Flume

Wave generators are widely used as a kind of equipment for simulating natural waves in the library model experiments,. The emphasis of the research on wave generator theory is how to simulate natural waves correctly. However, while making waves in labs, there is the secondary reflection wave due to the board of wave generator, and the phenomena doesn't occur naturally. In order to eliminate the effect of the secondary reflection waves, active-absorption wave making theory has to be developed, which is significant for making waves.On the wind-wave-flow flume in Tianjin Institute of Water Transport Engineering, the no-reflection wave making has been realized. The control system of the wave generator is drived by servomotor. The system controls the motion of the motor and ensures the accuracy of the motion.By analyzing the composition of the wavemaker system and its working principle, this paper has established the transfer function of the control system. According to the theory of small amplitude wave, the relational expression between transfer function and the wave factor is obtained by repeatedly testing. The effect of the regular wave and the irregular wave is verified respectively.This paper has deduced the motion control equation of the active-absorption wavemaker on the basis of absorption theory. For irregular wave , the observation wave in front of the board is composed of infinite regular wave with single frequency.But the single frequency is very hard to be known. The paper uses the constant substitute method, which is that using a typical frequency to represent the all frequencies of wave. A large quantity of experiments concerning both regular waves and irregular waves has been accomplished with active-absorption wave making method; and the stability of the wave shape and the absorption rate has been analyzed. Proved by experiment, the method is effective to absorbe the secondary reflection waves.According to the theory of solitary wave, the simulating of solitary wave has been implemented in flume and the characteristic of solitary wave has been researched. At the same time, this paper makes an introduction of the freak wave in nature. And its existence has been verified by simulating it in flume.