A STUDY ON STRUCTURE OF WIND VELOCITY DISTRIBUTION AND CORRESPONDING PRESSURE DEFICIT CHARACTERISTICS UNDER THE TORNADO-LIKE WIND FLOW AFFECTED BY SURFACE ROUGHNESS

In this study, PIV and wind pressure experiments were carried out under tornado-like wind flow affected by surface roughness. The authors discussed the effects of swirl ratio and roughness density on the velocity field and the pressure deficit characteristics near the surface. It was confirmed that the velocity field structure gradually transitioned by changing swirl ratio and roughness density. Next, the pressure deficit characteristics showed that the measured pressure was the lowest when the roughness density was 0.014 at any swirl ratio. In the above discussion, the models on the radial velocity distribution and the pressure deficit distribution were proposed.