| The experiments were carried out with flat V tip vane base on the theory that the higher power coefficient will be reached using wind turbine with tip vane. The effect of the power coefficient is different result form the different parameters of the tip vane.Firstly, the experiments were carried out at the outlet experimental area of the B1/K2 wind tunnel which belongs to the Inner Mongolia University of Technology. In this experiment, orthogonal test was taken and the optimum tip vane was selected which mad an obvious effect on the power coefficient of wind turbine. The wind turbine's radius is 0.7m and the aerofoil is NACA4415. 5 parameters of the tip vane included: frontal length, the ratio of frontal length to back length, width, frontal angle and back angle and 5 levers of every parameter were selected. Calculated and analyzed the result and the optimal tip vane are found conclusively. At the same time, the relative relationship between dimensions of tip vane and blade are found. The frontal length of the tip vane is 1.5% of the radial of wind turbine; the back length of the tip vane is 2 times of the frontal length of the tip vane; the width of the tip vane is 80% of the chord of the blade-tip. And the effect on the Cp of the wind turbine by Frontal Length is prominent.Next, by the result of the orthogonal experiment, the PIV (Particle Image Velocimetry) experiment was carried out in the inside experimental area of the B1/K2 wind tunnel which belong to the Inner Mongolia University of Technology. In this experiment, the flow field around the blade and the wake field had been measured, that's a good start at measuring these flow fields and making experiment in the inside experimental area. Broadcast tracer in a greet area was mastered using a 9708 fog machine and a good result had been obtained after dealt with the surface'glisten of the measured section.In the process of experiment 13 transects had been selected. The flow field of the sections had been measured at rating condition and the flow field of some sections had been measured at different conditions.Based on the analysis and comparison of the maps, four conclusions are reached. 1. The effect on the r/R=0.96 section to blade tip is prominent by the tip vane and the effect on the r/R=0.91 to blade root is neglectable. 2. The tip vortex is disappearing when fixed the tip vane and then 2 littler vortexes had appeared at frontal sect and back sect respectively. 3. At rating condition, at the r/R=0.34 section to r/R=0.23 section, the liquid was deviate from the surface of the sections and from the r/R=0.34 the nearer from the axes the section is, the nearer from the frontal point the deviated point is. 4. The width of the wake area of the r/R=1.0 section relate with the attack angle and rotate speed of the wind turbine. The higher the rotate speed of the wind turbine is and the littler the attack angle is, the shower the width of the wake area. And the length of the wake area is about 5 times long than the chord'length. ('r'is the radius of the section,'R'is the radius of the wind turbine)... |
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