摘要
浓缩风能装置的结构直接影响浓缩风能型风电机组的性能。在该文中,采用计算流体力学软件对浓缩风能装置进行结构优化。优化方案是在原模型扩散管后增加一段锥形管,并分析锥形管的母线长度d及偏转角β对浓缩性能的影响。分析结果表明,锥形管母线长度为0.4D(D为中央圆筒直径),偏转角为50°时的优化模型为较优模型。浓缩风能装置优化模型的浓缩性能由锥形管后方的漩涡和锥形管内壁面上的流动分离决定。漩涡的存在使浓缩风能装置优化模型的浓缩性能优于原模型。流动分离会使浓缩性能降低。使浓缩风能装置得到优化的最佳状态是锥形管后方出现一个强烈的漩涡,同时锥形管内壁面附近不出现强度较大的流动分离。
The structure of the wind concentrator will directly affect the performance of wind-concentrating turbine. In this paper, to optimize the structure, the CFD software was used. The structure was optimized by adding a new conical tube behind the diffuser of the original model, and the influence of both the generatrix length(d) and the deflection angle(β) of the conical tube on the concentrator was also analyzed. First, through the CAD software, the optimized model of a wind concentrator was built and a cylinder(diameter: 20 m;length: 30 m, coaxial with the model) was created. With the help of Boolean subtraction, the fluid field model was obtained by subtracting the optimized model from the cylinder. The patch conforming algorithm was used to mesh the fluid field and the mesh type was tetrahedral. Twenty inflation layers were divided in the thickness range of 1 cm marked on the optimization model. In the simulation, SST k-ω turbulence model was adopted, energy equation was used and heat exchange was considered. The air velocity, temperature, density, pressure, viscosity, thermal conductivity, constant pressure specific heat capacity, flow rate, turbulent kinetic energy k value and specific dissipation rate ω value were 10.83 m/s, 296.75 K, 1.044 kg/m3, 88 800 Pa, 1.85×10-5 kg/(m·s), 0.026 22 W/(m·K), 1 013 J/(kg·K), 3 552.048 kg/s, 0.165 382 m2/s2, 11.786 s-1, respectively. The inlet boundary was the mass flow inlet, and the velocity direction was perpendicular to the inlet boundary. Both the thermal boundary conditions of the wall of the concentrator and the shell of the fluid field were at fixed temperature, with a value of 296.75 K. Pressure outlet was used as the outlet boundary. The results of flow field calculation show that the model was optimal when the generatrix length and the deflection angle of the conical tube were 0.4 D and 50° respectively. The concentrating performance of the optimized model was determined by the vortex behind the conical tube and the flow separation on the inner surface of
作者
姬忠涛
田德
Ji Zhongtao;Tian De(College of Physics and Electronic Engineering,Qujing Normal University,Qujing 655011,China;State Key Laboratory for Alternate Electrical Power System with Renewable Energy Sources,North China Electric Power University,Beijing 102206,China)
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2019年第24期66-73,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
云南省地方本科高校联合专项-面上项目(2018FH001-053)
关键词
风能
计算流体力学
优化
浓缩风能装置
漩涡
流动分离
wind energy
computational fluid dynamics
optimization
concentrator
vortex
flow separation
