Research On The Methods Of Making Waves Using Rotary Valve Control

Wave generator is an important basic equipment in ocean engineering,coastal engineering,ship port and other fields.The hydraulic or motor drive are usually used to generate waves by controlling the wave making plate or wave making mechanism.In order to meet the requirement of high power and high frequency for wave generation,the phenomenon that large motor volume and rotary inertia is existed during using the motor drive in the case of heavy load and reciprocating direction change,and the abuse that small flow of servo valve is existed during using electro-hydraulic servo drive at high frequency.Under the condition of high power wave making,rotary valve controlled hydraulic wave making was selected to solve the wave making problem of high power and high frequency.Based on the theory of rotary valve control type driving system and the linear wave theory,the mathematical model of the rotary valve control type wave making was established.The control parameters of the rotary valve were connected with the generated wave parameters.The wave making experiment was carried out by setting up a wave making platform using rotary valve control.The feasibility of rotary valve controlled wave making technology was verified by comparing the experimental data with the theoretical simulation data.On this basis of experiment,the experiments of wave superposition were carried out.The main work of the paper is as follows:(1)Based on the structural characteristics and working principle of the rotary valve,mathematical model of the rotary valve controlled drive system was established,the relationship between the control parameters of rotary valve and the displacement of hydraulic cylinder was explored.The two-dimensional hydraulic force transfer function of the wave making theory for wave generator was derived,the hydraulic transfer functions of pushing wave making and rocking wave making were derived.The theoretical mathematical model of the rotary valve controlled wave making system was established by combining the rotary valve-controlled driving system with the theory of liner wave making.Matlab/Simulink simulation model was established.(2)For researching wave making condition under different system oil supply pressure,valve opening and wave frequency,the pushing-plate wave making experiment and rocking-plate wave making experiment were respectively carried out by the rotary valve controlled wave making experiment platform,the data of the displacement and wave data was collected and compared with the data obtained from the established simulation model.The results show that,the experimental wave wavelength data was consistent with the theory,and the error was less than 6%.The error between the plate displacement and wave amplitude and the theory was basically less than 10%.The error mainly comes from the error of mathematical model parameter setting and experimental equipment in wave making process.The experimental results verify the feasibility of the rotary valve controlled wave making technology.(3)On the basis of pushing plate wave making and rocking plate wave making experiment,The experimental data of pushing-plate wave making and rocking-plate wave making were compared and analyzed.The wave superposition experiments under different wave making modes and different control parameters were carried out.The experimental results show that the wave height of wave superposition was close to the theoretical expectation.The feasibility of generating wave superposition by rotary valve control was proved.