Numerical Investigation on Damage Patterns of Low Swirl Translating Tornadoes

Tornado is a destructive phenomenon which causes severe damage every year. To improve resistance of structures which face tornado، the flow field and factors which affect damage patterns of tornado need to be investigated. In this paper، numerical simulations of stationary and translating tornadoes are carried out using Ward-type simulator results and large eddy turbulence model. Validation for stationary case has been done with experimental work of Baker. The effects of peak winds، duration of intense winds and acceleration of translating tornado on damage patterns have been investigated. Results show that destruction is more intense at the side of the tornado that translational velocity and tangential wind velocity are added up. Moreover، peak wind velocity and duration of intense winds are important factors that have important effects on the destruction pattern of tall structures. However، the value of the translational acceleration of tornado is important for the design of all structures regardless of their heights.