한국해양대학교

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Performance Analysis of a Savonius Rotor for Wave Energy Conversion

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dc.contributor.author 모하메드아시드줄라 -
dc.date.accessioned 2017-02-22T02:25:35Z -
dc.date.available 2017-02-22T02:25:35Z -
dc.date.issued 2010 -
dc.date.submitted 2010-07-26 -
dc.identifier.uri http://kmou.dcollection.net/jsp/common/DcLoOrgPer.jsp?sItemId=000002174373 ko_KR
dc.identifier.uri http://repository.kmou.ac.kr/handle/2014.oak/8386 -
dc.description.abstract Ocean wave energy is rapidly becoming a field of great interest in the world of renewable energy. Significant advancements in design and technology are being made to make wave energy a viable alternative for our growing energy demands. Ocean waves are a significant resource of inexhaustible, non-polluting energy. Wave energy converters (WEC) provide a means of transforming wave energy into usable electrical energy. The development of these devices is undergoing rapid change. An overview of the various operating WEC is presented, classifying them according to shoreline, near shore and offshore applications. The prior concept of using an oscillating water column (OWC) with a savonius rotor at the bottom of the rear chamber as a potential WEC is of interest. (Under certain conditions and water depth, wave action in the OWC induces a reverse flow. As proposed, this reverse current could generate electric power by rotating the blades of a savonius rotor turbine). A numerical study of the savonius type direct drive turbine in typical chamber geometry of an oscillating water column chamber for wave energy conversion was carried out. The research deals with a numerical modeling devoted to predict the turbine efficiency in the components of an oscillating water column system used for the wave energy capture, the flow behavior is modeled by using the commercial code ANSYS CFX (11). Several numerical flow models have been elaborated and tested independently in the geometries of a water chamber with a savonius type wave turbines Constant periodic wave flow calculations were performed to investigate the flow distribution at the turbines inlet section, as well as the properties of the savonius type turbine. The flow is assumed to be two-dimensional (2D), viscous, turbulent and unsteady. The commercial CFD code is used with a solver of the coupled conservation equations of mass, momentum and energy, with an implicit time scheme and with the adoption of the hexahedral mesh and the moving mesh techniques in areas of moving surfaces. Turbulence is modeled with the k?e model. The obtained results indicate that the developed models are well suitable to analyze the water flows both in the chamber and in the turbine. For the turbine, the numerical results of pressure and torque were compared with each other. The primary stages of the research effort can be described as follows -
dc.description.abstract Firstly, a comprehensive literature survey was done to find those articles that deal specifically with wave energy conversion. Gleaned from this is the effect, that variances in technology, location, developments and etc (Appendix). Secondly, development of a 3D numerical wave tank using CFD that can represent the physical model to an appropriate order of accuracy whilst maintaining realistic computational effort. Furthermore, extend the numerical wave tank to include a detailed OWC to determine energy capture efficiencies. Thirdly, determine the effect of various 3 bladed savonius geometric parameters on efficiency Fourthly, A mitigation technique that involves altering the geometry of the OWC chamber inlet section was studied. Finally, the best geometric models were combined to obtain the highest efficiency for 5 bladed savonius rotor The results obtained show that with careful consideration of key modeling parameters as well as ensuring sufficient data resolution. The results of the testing have also illustrated that simple changes to the front wall aperture shape can provide marked improvements in the efficiency of energy capture for OWC type devices. -
dc.description.tableofcontents Chapter 1 INTRODUCTION. 1 1.1 General 1 1.2 Ocean Waves 2 1.2.1 Power Rating 6 1.2.2 Wave Energy Availability. 9 1.3 Reasons for a Renewed World Interest in Wave Energy 11 1.4 Wave Energy Converters. 16 1.4.1 Advantages. 16 1.4.2 Factors When Applying WECs 16 1.5 Classification of a Wave Energy Device. 17 1.5.1 Location. 17 1.5.2 Operating Principles 18 1.5.3 Directional Characteristics 19 1.5.4 Potential and Kinetic Energy 20 1.6 WECS Electric Power Generation 23 1.7 Challenges. 25 1.8 Numerical Analysis of Savonius Type Turbine for ... 29 1.8.1 OWC Type Wave Devices 32 1.8.2 Savonius Rotor. 34 CHAPTER 2 NUMERICAL ANALYSIS 37 2.1 Introduction. 37 2.2 Modeling 38 2.3 CFD Analysis Setup 42 2.3.1 Domain Setup. 42 2.3.2 Numerical Results. 44 2.2.3 Mesh Generation. 45 2.3.4 Boundary Conditions. 47 2.3.5 Wave Generation. 48 2.3.6 Multiphase 49 2.3.7 Solver Controls 50 2.4 Turbulence Modeling 52 2.4.1 k-ε model 54 2.4.2 The Shear Stress Transport Model. 55 CHAPTER 3 RESULTS AND DISCUSSION 57 3.1 General 57 3.2 Numerical Tank. 58 3.2.1 Numerical Wave Tank with OWC. 63 3.3 Reflector in the Rear Bottom of the OWC 66 3.4 Rotor Angle and Helical Blade Analysis 73 3.4.1 3 Bladed Savonius Rotor Angle Analysis 74 3.4.2 3 Bladed Helical Savonius Rotor Angle Analysis 82 3.5 OWC Inlet Section Analysis. 88 3.6 5 Bladed Savonius Rotor Analysis. 95 CHAPTER 4 CONCLUSION. 99 ACKNOWLEDGEMENT 103 REFERENCES. 104 APPENDIX A 112 -
dc.language eng -
dc.publisher 유동정보연구실 -
dc.title Performance Analysis of a Savonius Rotor for Wave Energy Conversion -
dc.title.alternative Performance Analysis of a Savonius Rotor for Wave Energy Conversion -
dc.type Thesis -
dc.date.awarded 2010-08 -
dc.contributor.alternativeName Mohammed Asid Zullah -
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기계공학과 > Thesis
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