Experimental and numerical analyses of multi-DBD plasma actuators to reduce wind loads and modify local flow on the roofs of low-rise buildings

The present study experimentally and numerically investigates the feasibility of applying multiple dielectric barrier discharge (multi-DBD) plasma actuators to reduce wind loads and modify local flow field on the roofs of low-rise buildings. Four arrangements of multi-DBD plasma actuators are placed on the roofs and induce four directions of wall jets. The results show that mean and peak negative pressure coefficients are negative no matter the plasma actuation is on or off. These wall jets decrease the absolute values of these pressure coefficients in different roof regions and succeed in modifying the local flow around the roof. The wall jet blowing from the trailing edge to the leading edge has the best effect on wind loads, since the absolute values of mean and peak negative pressure coefficients are respectively reduced by about 20% and 12% near the leading edge. The different variations of wind loads and the local flow for all arrangements are due to the compact of the directionality of the wall jets. The wall jet produces a strong suction region at the beginning of the wall jet, which leads to an obvious enhancement of wind loads in this region. Meanwhile, the wall jet induces a strong pressure region at the back of the wall jet, resulting in an apparent decline of wind loads.