Spelling suggestions: "subject:"QC find 930.51959"" "subject:"QC find 930.5959""
1 |
Performance Prediction Of Horizontal Axis Wind Turbines Using Vortex TheoryYucel, Burak 01 December 2004 (has links) (PDF)
iv
Performance prediction of HAWTs is important because it gives an idea
about the power production of a HAWT in out of design conditions without making
any experiments. Since the experiments of fluid mechanics are difficult to afford,
developing some models is very beneficial.
There are some models developed about this subject using miscellaneous
methods. In this study, one can find &ldquo / Vortex Theory&rdquo / among one of these theories.
Some basic 3D aerodynamics was discussed in order to make the reader to
understand the main subject of this study. Just after that, performance prediction of
constant speed, stall controlled HAWTs was discussed.
In order to understand the closeness of this theory to experiments, as a
sample, NREL &ldquo / Combined Experiment Rotor&rdquo / was considered. Performances
obtained by AEROPOWER, written in Visual Basic 6.0 and Excel combination, and
experimental results were compared for different wind velocities. Acceptable results
were obtained for wind speeds not much different than the design wind speed. For
relatively lower wind speeds, due to &ldquo / turbulence&rdquo / , and for relatively higher wind
speeds, due to &ldquo / stall&rdquo / , the program did not give good results. In the first case it has
not given any numerical result.
Power curves were obtained by only changing the settling angle, and only
changing the rotor angular speed using AEROPOWER. It was seen that, both settling
angle and rotor rpm values influence the turbine power output significantly.
|
2 |
Investigation Of Wind Effects On Tall Buildings Through Wind Tunnel TestingKayisoglu, Bengi 01 June 2011 (has links) (PDF)
In recent years, especially in the crowded city-centers where land prizes have become extremely high, tall buildings with more than 30 floors have started to be designed and constructed in Turkey. On the other hand, the technical improvements have provided the opportunity of design and construction of more slender structures which are influenced by the wind actions more. If the building is flexible, wind can interact with it so the wind induced oscillations can be significantly magnified. In order to analyze the response of such buildings under wind effects, wind tunnel tests are accepted to be the most powerful tool all over the world. In this study, a series of tests were performed in Ankara Wind Tunnel on a model building in the shape of a rectangular prism. For the similitude of flow conditions, passive devices were designed. The response of the model building was measured through a high frequency base balance which was designed specifically for this case study. Through the tests, the effects of turbulence intensity, vortex shedding and wind angle of attack on the response of the building were questioned. Finally, the results were compared with the results of various technical specifications about wind.
|
Page generated in 0.0421 seconds