Flow Control Study Based On Plasma Excitation

With the development of disaster prevention and reduction engineering and protective engineering,the research of wind-resistance has become a hot research area,wind load become the key factor in the structural design for tall buildings,and on low-rise rural buildings in coastal areas,reducing the effect of wind on buildings is of great significance.Based on low-rise building with flat roof,the plasma flow control technology is applied to the wind resistance of building structures,the flow control effect of plasma excitation on buildings is studied through wind tunnel test and numerical simulation,the conclusion can provide reference for wind resistance of buildings.Firstly,the wind tunnel pressure test and numerical simulation were carried out to study the wind pressure variation rules of flat roof buildings under wind field with turbulence less than 8% by applying plasma excitation in four directions,the results show that the negative pressure near leading edge can be reduced by the plasma excitation from trailing edge to leading edge and the plasma excitation from middle to the leading and trailing edges,but applying the plasma excitation from trailing edge to leading edge is better to reduce negative pressure near leading edge,applying plasma excitation from leading and trailing edges to the middle has an obvious effect on reducing the negative pressure in the middle of the roof.Secondly,the wall jet induced by plasma excitation in different directions under the condition of clam wind is studied by numerical simulation,the results show that the mean velocity of the wall jet is linear monotone increasing distribution from the leading edge to the trailing edge of the roof under downwind plasma excitation,the mean velocity of the wall jet is linear monotone increasing distribution from the trailing edge to the leading edge of the roof under upwind plasma excitation,the mean velocity of the wall jet is inverted trapezoidal distribution under plasma excitation from middle to the leading and trailing edges,the mean velocity of the wall jet is trapezoidal distribution under plasma excitation from leading and trailing edges to the middle.Finally,the effects of wind pressure control on flat roof under different directions of the plasma excitation in wind fields A,B,C and D were studied,theresults show that under the same wind field,the region of roof where the wind pressure reduces varies with the direction of the plasma excitation,the wall jet from leading edge to trailing edge mainly reduces the negative pressure near the trailing edge of the roof,the wall jet from trailing edge to leading edge mainly reduces the negative pressure near the leading edge of the roof,the wall jet from middle blowing to leading and trailing edges mainly reduces the negative pressure near the leading and trailing edges of the roof,the wall jet from leading and trailing edges blowing to middle mainly reduces the negative pressure near the middle of the roof.Under the wall jet in the same direction,the region where the negative pressure reduces and the negative pressure reduced value of roof varies with the turbulence intensity,with the increase of turbulence intensity,the control effect is getting better and better.