A 10m height chimney has a 2.0m x 2.0m square cross section. The wind blows horizontally in a direction which is parallel to one of the diagonals of the cross section.
Careful measurement shows that, at height y from the ground, the magnitude of the wind velocity is given by:
u = 1.16 * Unom* log(750*y) for y > 1m
where Unom = 5m/s.
The density and viscosity of air are 1.2 kg/m3 and 2.0x10-5 m2/s respectively.
a) Estimate the force on the chimney and the bending moment at the bottom of the chimney. You may assume that the effect of the wind on the first 1 m height of the chimney has a negligible effect on the force and the moment.
b) How would you improve the accuracy of your estimation?