Flow Field Simulation And Structure Optimization Of Concentrated Wind Energy Device

The concentrated wind energy turbine(CWET) is a kind of wind power generator, which can condense the thin and unstable wind into the accelerated, rectified and homogenized one by the concentrated wind energy device(CWED). It is mainly composed of CWED, generator, rotor, empennage, rotary, tower and so on. CWED is one of the major components of this turbine, its structure directly affecting the output power of the turbine. CWED mainly consists of three sections, the shrinkage pipe located in the front, the central cylinder located in the middle and the diffuser located in the rear. When the fluid with low density and high turbulence flows through the CWED, it is accelerated, rectified and homogenized into the high quality one. Then the turbine rotor is forced to spin, so that the high quality electric power is obtained. So as to enhance the efficiency of the CWET, the CWED taken as the study object, the geometry model and the mesh model were respectively built by using the three-dimensional modeling software and CFD software. Meanwhile, the FLUENT software was used to perform numerical simulations. The main work of the paper is as follows.(1) Verify the feasibility of the numerical simulation method applied to the internal flow field of the CWED. The geometry model and the mesh model of contractor and diffuser arrangement are established, which is similar with the CWED in the references. Then its internal flow field is simulated, the computational results compared with the experimental results. Results show that there is a good match between the simulated results and the experimental results. It turns out that the numerical simulation method is feasible.(2) Research on the influence of different turbulence models on the internal flow field of the CWED. The geometry models and the mesh models of CWED are established using different turbulence models which are Spalart-Allmaras Model, Standard k-ε Model, Standard k-ω Model and Reynolds Stress Model (RSM). Results show that Standard k-ω Model is more suitable for the internal flow field simulation of the CWED;(3) Research on the influence of different geometric parameters on the internal flow field of the CWED. The simulations of the internal flow field with different contractor angles, diffuser angles and central cylinder lengths are conducted respectively. Results show that the diffuser angle has more influence on the internal flow field. When the diffuser angle is 80° and the diffuser length is 322 mm as the original design value, the internal flow field has the largest velocity of 26.16 m/s;(4) Research on the influence of different inflow wind speed on the internal flow field of the CWED. Under different inflow wind speed, the internal flow field of an optimized model is simulated. Results show that there is a linear relationship between the maximum velocity of the flow field and inflow wind speed.