Research On Hydrodynamic Characteristics Of Pelamis Wave Power Device Based On CFD

With the development of society and growing reduction of fossil fuel, it notonly triggered a series of environmental problems, but also led to energy crisis.Therefore, people have turned their attention to marine development, especiallywave energy, which is renewable, clean and abundant on the earth. And research onefficient and practical Pelamis wave energy converter has potential significance andbroad prospects, due to randomly changing marine environment and waveinstability.Theoretical analysis on Stokes wave is conducted, providing the First OrderStokes Wave Governing Equations and boundary conditions, as well as the FirstOrder Stokes Wave expression for velocity potential and wave height equationaccordingly. Based on the First Order Stokes Wave theory, a two-dimensionalnumerical sink is established through CFD commercial software FLUENT,generating wave through UDF programming by adding mass source term andmomentum source term to the fluid field Governing Equations, and realizing waveabsorption by adding damping source term at the sink end. Comparing the differencebetween theoretical solution and simulation solution with the same wave parameters,the essay observes the wave simulation rules and wave absorption effect, andverified the feasiblility of wave numerical simulation to carry out Fluid-solidcoupled calculations of Pelamis wave energy converter accordingly.The thesis gives the single buoy motion flow governing equations andboundary conditions on the free face and carries out theoretical analysis of influencefactors for added mass and added damping. Accordingly, based on the calculationprinciple of added mass and added damping through FLUENT, the essay establishesthe single buoy numerical simulation models, which is made to be slight vibrationby using UDF programming and dynamic mesh technique. Furthermore, it discussesthe force of single buoy in the case of heave, surge, pitch respectively and obtainsthe results of added mass and added damping coefficient.This article summarizes the working principle of Pelamis wave power device,especially the spatial stress analysis, and establishes the Fluid-solid coupledmathematical model of Pelamis wave power device according to the rigid bodymotion theory and Lagrange Equations. What’s more, based on the two-dimensionalnumerical sink technique and Fluid-solid coupled mathematical model, the essaycombines the viscous fluid equations with Kinetic equations by using UDFprogramming and dynamic mesh technique. It discusses the force and motion ofdual-buoy with the same wave parameters and explains why dual-buoy can drive the hydraulic cylinder to reciprocate. At last, the essay studies the relative angular pitchvelocity, and analyzes the impact of wave amplitude on the power of Pelamis waveenergy converter.