Research On Hydrodynamic Characteristics Of Savonius Rotors

Savonius rotor is a type of vertical axis generator,which accommodates two-way flow and has good self-starting performance.Compared to wind power,the density of water is about 800 times that of air;thus,the turbine can obtain enough energy even at low flow rates.Although the wave energy reserves are amazing,the efficiency of wave energy generation devices is seriously restricted due to the erratic sea condition in the process of energy conversion to mechanical power generation.In order to make full use of the compact space of offshore platform and the potential wave energy,many pipes or structures similar to pipes can be improved to become a part of power generation and realize the recycling of resources.Many non-production pipelines,such as TLCDs,water-sinking columns,domestic water pipes,etc.,can be converted by adding built-in turbines.Firstly,the Savonius turbine performance prediction theory is derived based on the stagnation pressure and impulse momentum theory.Segmentation is carried out by different production sources,and the performance of the turbine is integrated after segmentation analysis and calculation thus characterizing the applicability of the theory under low tip speed ratio.Secondly,the computational fluid dynamics method is used to establish the twodimensional and three-dimensional models of the two-blade Savonius-type rotor in the open flow field.The changes laws of rotor performance can be given through sensitivity analysis for rotor angle,tip speed ratio,overlap ratio,aspect ratio and other parameters,which assist structure optimization.Then,depended on the above-mentioned optimized configuration of the rotor,the narrow channel model is selected to simulate the pipe flow environment,and the influence of the wall distance on the performance of the rotor under constant flow is investigated.The appropriate side wall distance is chosen to realize the reciprocating flow under the three-dimensional model.From the perspective of time domain analysis,periodic rotation analysis and mechanical property analysis,the performance of Savonius rotor under different working conditions is evaluated.Finally,a U-shaped oscillating water tank device was designed and built,and a gas-driven device was used to manufacture a stable reciprocating flow in channel,thereby creating a simulation environment for subsequent experiments.The purpose of this article is to investigate the hydrodynamic characteristics of Savonius-type rotors with different incoming and boundary conditions to verify their potential for use in tuning liquid column dampers for power generation.At the same time,theoretical derivation and numerical simulation results can provide reliable data support for subsequent system design and structural optimization.