Fluid forces acting on a tree

Abstract

Flow and fluid forces acting on several kind of trees in large scale wind tunnel were measured by using wind flow velocity meter and load cell. Drag coefficient of drag forces acting on a tree decreased with increase of Reynolds number because projected frontal area of tree canopy in still air decreased with increase of incident flow velocity. The reverse flow was not found at down stream region of tree under the influence of the flow passing through the tree canopy. The recovery of flow velocity in the wake of tree was more slow compare to that of circular cylinder in uniform flow. The impulsive forces acting on a pine tree were also measured.

Strength assessment of rice hills from different planting distance by loading simulation

“…According to the owner of rice field in Figure 4d, the Inpari 30 variety was planted in double row spacing. In the field, plant spacing might not be the only factor that determines lodging incidentas other causes have been mentioned by previous authors (Mochida et al, 2008;Hayashi et al, 2011;Selino and Jones, 2013;Tadrist et al, 2015;Barnard and Bauerle, 2016). Therefore, it is interesting to study rice canopy morphology that determines sturdiness under strong wind impact.…”

“…In this case, we assume that lodging is due to weak rice hill. It is well known that crop sensitivity to strong wind impact and lodging is determined by wind speed, species, variety, growth stage, plant architecture, nutrient status, plant biometry and leaf orientation (Hayashi et al, 2011;Ishimaru et al, 2012;Selino Keywords: Double row spacing, extreme weather, lodging simulation, strong wind, weight holding capacity and Jones, 2013; Sridevi and Chellamuthu, 2015;Tadrist et al, 2015;Martinez-Vazquez, 2016). According to Niu et al (2016) combination between strong wind and heavy rainfall causes more marked damage in wheat.…”