| Research on a new concept of energy saving device is conducted in this dissertation.An energy recovering turbine is arranged behind a marine propeller,generated by the slipstream of the propeller,and extracts the kinetic energy of slipstream.The core of this research is the integrative design method for propeller and energy recovering turbine.A conventional propeller and a marine current turbine is applied as prototypes,which are optimized individually,and constitute a combined propulsor.The first part of this research is theoretical methods of performance prediction for both propeller and turbine.Vortex Lattice Method is applied for propeller,and Blade Element Momentum Theory(BEMT)is modified in this dissertation,since the conventional theory is not applicable for inflow condition of a turbine behind a propeller.Secondly,integrative optimal design is conducted for both propeller and turbine.Optimization for propeller is conducted as the first step,and an optimum geometry of propeller is obtained based on Genetic Algorithm(GA),as well as an appropriate objective function and GA controlled VLM program.CFD simulation is applied as validation,and performance data and simulation of the slipstream is exported to the module for turbine design.The second step for integrative design is the optimization for turbine,which is based on GA as well.Optimization for 2-dimensional hydrofoils is conducted first,and the optimal method from 2D foils to 3D blade is established.Performance data of propeller is applied in the objective function of turbine design,and the slipstream of propeller is applied as the inflow condition of turbine.Several optimal turbine blade is obtained based GA and GA controlled modified BEMT,and the optimum one is selected among them,as the final plan for turbine.Finally,CFD computation model is established for the combined propulsor,and integrative simulation is conducted to as the validation,and performance in general is evaluated based on the CFD simulation as well. |
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