Currently, only five models for predicting wind flow characteristics around windbreaks exist. However, there are no widely accepted guidelines to determine the windbreak performance. Traditionally, windbreaks have been studied by many researchers in order to understand the influence of different windbreak structures and approaching wind characteristics on the leeward wind characteristics. The purpose of this is to provide guidance for the optimal windbreak design as well as to develop a tool for predicting the wind characteristics behind the structure. This thesis seeks to quantify the wind reduction in the sheltered area of the ‘forest’ when configured with various platform cross-sectional shapes, and arrangements as well as dimensions of the column tubes. The floating forest is comprised of a concrete wedge-shaped floating platform with arrays of tubes mounted on its inclined surface that collectively act as a windbreak and a breakwater. To respond to severe wind and wave hazards globally, an innovative hybrid floating windbreak-breakwater structure, also called ‘floating forest’, is proposed for sheltering vulnerable areas. The numerical results shows that Realizable k-ε turbulence model exhibit better agreement at the prediction mean velocity and turbulence kinetic energy while Standard k-ω turbulence models exhibit better agreement at the prediction of mean pressures coefficients. It is seen from the surface mean pressure distributions that the 15° roof pitch causes more critical suction on the roofs than those of the 30° and 45° roof pitches.
#The wind rises flowstate free#
Largest values of turbulence kinetic energy for entire flow field occur at height of the roof level and they prove the presence of the mixing layer between the free stream flow and reverse flow region. These regions are much stronger and spread up to the roof ridge with increasing roof pitch. Recirculation regions occur on the leeward part of roofs and at the behind of the models due to flow separation. The mean velocity and turbulence kinetic energy profiles are influenced by the roof pitch. 3D solutions of the flow fields were obtained with two different turbulence models.
Flow visualization, measurements of velocity and surface pressure around the models placed in wind tunnel were made. The models of the Belgian Building Research Institute (BBRI) test building with a scale of 1:100 were studied with 15°, 30° and 45° roof pitches for the wind direction of 90°. In this study, the turbulent flow fields on the low-rise building models with gabled roofs having different pitch angles immersed in atmospheric boundary layer have been investigated experimentally and numerically.
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