Numerical Methods to Predict Characteristics of Oscillating Water Column for Terminator-type Wave Energy Converter

摘要

Two numerical methods are described for analyzing a terminator-type wave energy conversion device under the condition that the linear water wave theory is applicable. Two methods are proposed to calculate the device characteristics of an oscillating water column (OWC) type. One uses the flow rate and gauge pressure in the air chamber directly, because in this system the interaction between the OWC and the turbine is found to be controlled only by the flow rate and the pressure drop through the turbine. The other method uses the equation of the floating body motion in a manner similar to the equivalent floating body approximation. The relations between these methods are also examined. The hydrodynamic performance with frequency from zero to infinity is required in the simulation of irregular waves. However, resonance occurs when the air chamber breadth is nearly equal to multiples of half a wavelength. The impulse response function is then modified in order to eliminate the effects of the resonance frequency. Finally, it is confirmed that these solutions give good agreement with the experimental results.