Wave generation characteristic analysis of piston and flap type wave maker with rotary-valve-control vibrator

2020 ◽  
Vol 26 (15-16) ◽  
pp. 1297-1308 ◽  
Author(s):  
Yi Liu ◽  
Yuxi Zheng ◽  
Ruiyin Song ◽  
Junhua Chen ◽  
Heng Jin
Keyword(s):  
Wave Amplitude ◽  
Wave Generation ◽  
New Wave ◽  
Rotary Valve ◽  
Characteristic Analysis ◽  
Frequency Wave ◽  
Type Wave ◽  
Wave Maker ◽  
Axial Opening ◽  
Valve Control

Wave maker is one of the most important experimental equipment in marine engineering. To meet the demands of simulation of higher wave amplitude and compare the effect of piston and flap type wave generation, a new wave generation device was proposed and a new piston and flap type wave maker with a rotary-valve-control vibrator was developed. A mathematical model of the new wave maker was established and analysed by Simulink, and a series of experiments were conducted on the wave maker to analyze wave generation characteristics. The results show that the wave maker can adjust the distance of wave paddle and generate different regular waves. The bigger the axial opening size of the valve port, the larger the wave paddle amplitude and the wave amplitude; the higher the pressure, the higher the wave paddle amplitude and the wave amplitude. High frequency wave making is more efficient than the lower one, and piston type wave making is more efficient than those wave makers that generate waves by flap type.

scholarly journals Loop-Type Wave-Generation Method for Generating Wind Waves under Long-Fetch Conditions

2017 ◽  
Vol 34 (10) ◽  
pp. 2129-2139 ◽  
Author(s):  
Naohisa Takagaki ◽  
Satoru Komori ◽  
Mizuki Ishida ◽  
Koji Iwano ◽  
Ryoichi Kurose ◽  
...  
Keyword(s):  
Wind Wave ◽  
Wind Waves ◽  
Peak Frequency ◽  
Wave Generation ◽  
New Wave ◽  
Wave Tank ◽  
Irregular Wave ◽  
Wind Speeds ◽  
Type Wave ◽  
Wave Generator

AbstractIt is important to develop a wave-generation method for extending the fetch in laboratory experiments, because previous laboratory studies were limited to the fetch shorter than several dozen meters. A new wave-generation method is proposed for generating wind waves under long-fetch conditions in a wind-wave tank, using a programmable irregular-wave generator. This new method is named a loop-type wave-generation method (LTWGM), because the waves with wave characteristics close to the wind waves measured at the end of the tank are reproduced at the entrance of the tank by the programmable irregular-wave generator and the mechanical wave generation is repeated at the entrance in order to increase the fetch. Water-level fluctuation is measured at both normal and extremely high wind speeds using resistance-type wave gauges. The results show that, at both wind speeds, LTWGM can produce wind waves with long fetches exceeding the length of the wind-wave tank. It is observed that the spectrum of wind waves with a long fetch reproduced by a wave generator is consistent with that of pure wind-driven waves without a wave generator. The fetch laws between the significant wave height and the peak frequency are also confirmed for the wind waves under long-fetch conditions. This implies that the ideal wind waves under long-fetch conditions can be reproduced using LTWGM with the programmable irregular-wave generator.

scholarly journals Numerical Investigation of Wave Generation Characteristics of Bottom-Tilting Flume Wavemaker

2020 ◽  
Vol 8 (10) ◽  
pp. 769
Author(s):  
Hsin-Erh Wang ◽  
I-Chi Chan
Keyword(s):  
Computer Model ◽  
Water Depth ◽  
Numerical Experiments ◽  
Wave Amplitude ◽  
Laboratory Data ◽  
Phase Speed ◽  
Good Alternative ◽  
Wave Generation ◽  
New Wave ◽  
Wave Generator

Motivated by the recently developed bottom-tilting wavemaker specially designed for tsunami research, we propose to investigate numerically the wave generation mechanism of this new wave generator. A series of numerical experiments is carried out using a RANS-based computer model to evaluate the effects of wavemaker length, bottom displacement, motion duration, and water depth on the wavelength, wave amplitude, phase speed, and waveform of the leading waves produced by the bottom-motion wave generator. Numerical results fit well with the existing laboratory data. Explicit equations for the wavelength and wave amplitude are developed and can serve as the guideline for wave generation. Encouraging results suggest that bottom-tilting wavemaker is a good alternative to the traditional piston-type wavemaker for tsunami research.

scholarly journals Simple Push-Type Wave Generating Method Using Digital Rotary Valve Control

2020 ◽  
Vol 33 (1) ◽  
Author(s):  
Yi Liu ◽  
Jiafei Zheng ◽  
Ruiyin Song ◽  
Qiaoning Xu ◽  
Junhua Chen ◽  
...  
Keyword(s):  
Rotary Valve ◽  
Type Wave ◽  
Generating Method ◽  
Valve Control

scholarly journals A Parametric Study of the Wave-Generation Performance of a Piston-Type Wave Maker

2019 ◽  
Vol 33 (6) ◽  
pp. 504-509
Author(s):  
Do-Soo Kwon ◽  
Sung-Jae Kim ◽  
Weoncheol Koo
Keyword(s):  
Parametric Study ◽  
Wave Generation ◽  
Type Wave ◽  
Wave Maker

Orthogonal Frequency Ultrasound Vibrometry

2010 ◽  
Author(s):  
Yi Zheng ◽  
Aiping Yao ◽  
Shigao Chen ◽  
Matthew W. Urban ◽  
Randy Kinnick ◽  
...  
Keyword(s):  
Wave Amplitude ◽  
Radiation Force ◽  
Sinusoidal Signal ◽  
Frequency Wave ◽  
Array Transducer ◽  
Ultrasound Radiation ◽  
Ultrasound Intensity ◽  
Tissue Region ◽  
Sinusoidal Signals ◽  
Frequency Ultrasound

New vibration pulses are proposed to increase the power of shear waves induced by ultrasound radiation force in a tissue region with a preferred spectral distribution. The new pulses are sparsely sampled from an orthogonal frequency wave composed of several sinusoidal signals. Those sinusoidal signals have different frequencies and are orthogonal to each other. The phase and amplitude of each sinusoidal signal are adjusted to control the shape of the orthogonal frequency wave. Amplitude of the sinusoidal signal is increased as its frequency increases to compensate for higher loss at higher frequency in the tissue region. The new vibration pulses and detection pulses can be interleaved for array transducer applications. The experimental results show that the new vibration pulses significantly increases induced tissue vibration with the same peak ultrasound intensity, compared with the binary vibration pulses.

White noise wave generation method controlled by a rotary valve

2020 ◽  
pp. 107754632097480
Author(s):  
Yi Liu ◽  
De-xin Chen ◽  
Heng Jin ◽  
Tao Wang
Keyword(s):  
Theoretical Model ◽  
Spectral Density ◽  
White Noise ◽  
Transmission Function ◽  
Wave Generation ◽  
Control Parameters ◽  
Rotary Valve ◽  
Variable Amplitude ◽  
Energy Spectral Density ◽  
Marine Engineering

To meet the demands of white noise waves with different and higher energy spectral density, a new white noise wave generation method was proposed and a corresponding wave-making system controlled by a rotary valve was developed. The theoretical model of the new method was established, and the hydraulic transmission function of the wave-making system was solved. After the control parameters of the white noise waves in the wave-making system were obtained, the experiment tests were carried out to generate the white noise waves, and its energy spectral density was analyzed by Fourier analysis. The results show that white noise waves with different amplitudes have different energy spectral densities. And the energy spectral density of the generated waves is approximately a constant. Therefore, the present white noise wave generation method is feasible in marine engineering tests, and the wave with variable amplitude and higher energy spectral density can be generated.

Design of Digital Filter Based on Numerical Simulation

2014 ◽  
Vol 539 ◽  
pp. 79-83
Author(s):  
Chuan Ting Wei ◽  
Quan Li Ning ◽  
Dong Chen
Keyword(s):  
Numerical Simulation ◽  
Mathematical Model ◽  
Digital Filter ◽  
Sampling Frequency ◽  
New Wave ◽  
Matlab Software ◽  
Frequency Wave

In MATLAB software, it has FDATool toolbox, which can design digital filter specific according to specific circuit, and analyze the performance of the filter according to the parameters of filter. In this paper we establish simulation mathematical model of digital filter based on the calculation principle of distributed multiplication accumulator. According to the logic algorithm we design delay algorithm of digital filter, and use MATLAB software to do simulation on amplitude frequency and phase frequency of digital filter. After superposition of different sampling frequency wave we get new waveform, and realize the digital filter for the new wave. It proves the availability of mathematical model and the program, and provides the technical reference for the design of digital filter.

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