Application of through-building openings for wind energy harvesting in built environment

Abstract

This study investigated mean flow characteristics and structure of flow inside through-building openings with five different layout configurations for the purpose of wind energy harvesting. Two-dimensional Particle Image Velocimetry (PIV) was employed and validated against a series of Cobra probe measurements. The mean flow characteristics including streamwise and vertical mean velocity were investigated at the wind direction parallel to the corridors of the through-building openings. The coherent structure of flow was studied, using two-point cross-correlation and a simple flow visualisation. The results showed that creating recessed regions at inlet and outlet of the openings and using curved walls at corners increase the mean velocity at the middle of the corridor by approximately 25%. When using converging-diverging passages for openings, the mean velocity increases by approximately 33%. The two configurations exhibit better performance in attuning the flow to be more inform and steady in a larger portion of the corridor, and hence these configurations have the capacity to enhance the performance of a potential wind turbine inside the corridor. The confined area of corridors contributes to the progressive reduction of undesirable characteristics of the cavity flow including vertical mean velocity, and streamwise and vertical velocity fluctuations along the corridor.