Wind tunnel experiment for wind breakage of Actinidia deliciosa P. shoots

Abstract

This study investigates the wind-breakage biomechanics of Actinidia deliciosa P. using varying degrees of free-stream turbulence and different physical parameters of plant shoots. Two different turbulent boundary layers (TBL) of wind were simulated inside a wind tunnel test section. The relationship between the load capability and the actual load of shoots was evaluated by using a specific failure criterion. The responses of the shoots to the on-coming wind velocity were estimated quantitatively using three physical parameters: the speedspecific drag, the E-value, and the factor of safety. The E-value of shoots exposed to a highly turbulent condition (TBL type B) is higher than those exposed to a less turbulent one (TBL type A). As the value of the length-diameter ratio (L/D) increases, the peak location of the speed-specific drag shifts towards higher wind speed and the E-value likewise increases. In addition, with increasing L/D, the factors of safety dwindle regardless of wind speed. The trend in the relationship between L/D and the factor of safety for both TBL types is similar.