###### Abstract  
The present research aims to explore, by large-eddy simulation (LES), the potentiality and mechanism of multiple surface dielectric barrier discharge (multi-SDBD) plasma actuators to manipulate mean and fluctuating wind loads on a low-rise building. Three actuator configurations are located on the roof to induce directional wall jets in different directions. The effects of these configurations on flow structure and wind loads are studied in absence and presence of approaching flow. Results show that all subgrid-scale models can obtain accurate roof pressure, and for the diffusion and convection terms, the bounded central differencing scheme can provide more accurate predictions for the roof pressure. The control impact of active actuators gradually weakens with the increase of the approaching flow velocity. The direction of the wall jet can determine the position of the limited roof region with the reduced mean pressure coefficient. The multi-SDBD actuators continue to absorb the upstream flow and blow this flow downstream, meaning the wall jet exerts strong pressure on the local roof area at the end of the jet, which results in a significant reduction of the mean pressure coefficient. Furthermore, the counter-rotating vortices caused by the wall jet restrain the size and strength of the vortex shedding, thereby achieving the purpose of reducing the fluctuating pressure coefficient. Further analysis of the instantaneous vorticity fields indicates that the intensity and size of streamwise shedding vortices can be restrained by small-scale spanwise vortices induced by the plasma actuators. Under the action of the wall jet blowing from the trailing edge to the leading edge, the fluctuating lift and drag coefficients can be reduced by over 15% and the fluctuating pressure coefficient can be reduced by about 20% from the no actuation situation. flow control; plasma actuators; low-rise buildings; control mechanism; fluctuating wind load; computational fluid dynamics +
Footnote †: journal: Applied  
overturned, causing the failure of gable walls and even complete collapse of the building. Hence, it is necessary to adopt effective strategies to reduce wind pressures on the surface of the roof. Many passive and active flow control technologies have been implemented to improve the aerodynamic characteristics of different obstacles. As for buildings, typical passive control strategies have included local shape modifications and additional ancillary structures. The experimental results of [PERSON] et al. [1] showed that facade appurtenances equipped on the four side faces of high-rise buildings could greatly restrain the variation range of negative peak pressure, and the largest value of this pressure could be reduced by about 42% on the higher leading corner. [PERSON] et al. [2] showed that high wind-induced suctions on the building envelope could be reduced by over 25% after simple architectural elements, such as trellises and ribs, were installed on a low-rise building. [PERSON] et al. [3] found that the large chamfers for roof edges can reduce the drag force of low-rise buildings by nearly 20%, and a 28% uplift reduction was achieved by replacing sharp roof edges with airfoil edges. [PERSON] et al. [4] pointed out that roof spoilers close to the gable wall had a noticeable reduction effect on wind pressures on the roofs of low-rise, gable-roof buildings, and mean wind pressure can be reduced by 95% on the local roof area. However, these passive methods had a limited operating range. The control effects of these methods were often not optimal and even had an adverse impact on system performance, as they did not operate within the original design conditions. In recent years, various active control strategies have been gradually applied to decrease wind loads of different structures. For example, [PERSON] et al.