MODIFICATION FOR IRREGULAR WAVE GENERATION SYSTEM IN NTU TOWING TANK
Other Title
建置拖航水槽不規則波浪生成系統
Journal
Journal of Taiwan Society of Naval Architects and Marine Engineers
Journal Volume
44
Journal Issue
2
Start Page
41
End Page
47
ISSN
10234535
Date Issued
2025
Author(s)
Abstract
The towing tank at National Taiwan University is approaching its 40th anniversary and is equipped with a linear wave generator. This system employs a hydraulically controlled inclined-plate mechanism to perform regular reciprocating motions. Given the increasing demand for experimental testing of ships and floating wind turbines under real sea conditions, enhancing the practicality of the wave generator in the towing tank is essential. This study develops the application of irregular waves based on the fundamental framework of regular waves by superimposing multiple regular waves to generate a specified wave spectrum in the time domain. However, the frequencies of different regular waves exhibit a nonlinear relationship with the generated signals, making direct superposition at the signal end unfeasible. To address this, the study employs feedback control for regular wave generation, measuring wave heights at various locations within the tank and tracking the stroke of the wave-making plate. These measurements are then used to calculate the mechanical energy conversion efficiency of the wave-making plate. By comparing these results with theoretical values from potential flow theory, the study establishes the relationship between the stroke of the wave-making plate and wave height. Based on this mechanism, future experiments can select appropriate stroke amplitudes and frequencies for the wave-making plate, as well as adjust the water depth in the tank, to achieve the desired experimental conditions. Moreover, this approach can also be adapted to simulate specific wave spectrum conditions, thereby supporting more precise sea-keeping tests.
Subjects
Feedback Control
Flap-Type Wave Maker
Irregular Waves
Regular Waves
Publisher
Taiwan Society of Naval Architects and Marine Engineers
Type
journal article