| Summary: | 碩士 === 國立臺灣海洋大學 === 機械與機電工程學系 === 103 === This thesis aimes to study the performance of an Oscillating Wave Surge Converter (OWSC) under different wave conditions. The capture factors are compared among different sets of parameters, including 3 wave heights and 3 wave periods. A numerical simulating wave-maker water tank is established by using computational fluid mechanics software ANSYS FLUENT. Wave-maker simulation is achieved by applying moving boundary conditions to wave equations. The fluid potential at fluid/air interface is observed by VOF (Volume of Fluid) method. Numerical model of high reliability is established to provide the tool for the design of wave energy converters (WEC) and the verification of analytical solutions.
It is recognized in literatures that the matching of wave period and the nature period of WEC is essential for better performance. Therefore, this thesis studies different wave periods and wave heights. The flow field around the flapper is observed at the instant of unsteadies oscillation. The capture factors are computed and compared under different wave conditions.
The basic wave condition for simulation is 7.5 cm wave height with 1.56 seconds wave period which is the 1/20 scaling model of the average nearshore wave condition at nearshore of Keelung. The WEC of this study is a bottom-hinged flapper without external loading. Other wave conditions of 1, 2, 2.5, 3 seconds wave periods and 10 cm, 12.5 cm, wave heights are studied as well. The results of simulation show that the capture factor is remarkably influenced by wave period while only slightly enhanced by increasing wave height. The largest capture factor obtained in this study is 13.99% at the wave condition of 7.5cm wave height with 2 seconds wave period.
Keywords: Numerical Simultion, ANSYS FLUENT, Oscillating Wave Surge Converter, flap, Capture factor, Natural period
|
|---|
