수직축 조류 발전 터빈의 성능 해석 및 설계

Abstract

This thesis deals with the design and performance analysis of vertical-axis tidal current turbine (VAT). VAT is well-known as its superior starting and operational abilities regardless of flow direction, while HAT shows the better turbine efficiency than most of VAT. After an extensive literature survey on tidal current power generation, the status and prospects of tidal current energy were summarized to briefly figure out the research direction. Hydrodynamic characteristics of both VAT and HAT (horizontal-type turbine) were also investigated.

For the analysis of VAT, the numerical approach was made by using the commercial CFD software FLUENT. GAMBIT was used for the grid generation of 2-D as well as 3-D models. Some typical calculated results were compared to available experimental data to validate the current numerical result. Although 3-D flow analysis was also made and introduced to investigate the flow characteristics in overall, most of calculated results were obtained using 2-D analysis due to its relative simplicity and relevance in massive calculations especially for the parametric study by varying several parameters to improve the turbine performance. In the present study, parameters such as number of blade, blade chord, solidity, pitch and blade chamber were varied for the wide range of TSR (tip speed ratio) to find out the best possible combinations providing the best hydrodynamic performance. The finally obtained VAT needs to be validated by further experimental investigation.