Numerical study of impact of fasade ribs on the wind field and wind force of high-rise building under atmospheric boundary layer flow

Fasade appurtenances are found to be able to improve the aerodynamic performance of tall building. In present paper, impact of fasade ribs on the flow structure and wind force of high-rise building are evaluated through LES approach under atmospheric boundary layer flow. It is found that horizontal ribs can significantly increase the size of wake vortex and suppress the near-wall vertical flow. Vertical ribs obviously affect the flow separation due to the introduction of local recirculation, which induces a narrow shear layer and near wake. Combination of horizontal and vertical rib can together affect the flow structure. All arranged ribs could alleviate the fluctuating wind near the sidewall. The change of wind filed will alter the wind pressure distribution and overall wind force. Horizontal ribs slightly reduce the mean wind pressure on sidewall. Vertical ribs clearly decrease the mean leeward suction. Facade ribs with different arrangement significantly reduce fluctuating wind pressure on the lateral and leeward wall. All models with ribs have smaller wind force than that of reference model, the maximum reduction ratio of drag and lift reach 26% and 47%, respectively.