CIVIL ENGINEERING HYDRAULICS ANY FEED BACK ON HOW TO SOLVE

CIVIL ENGINEERING HYDRAULICS – ANY FEED BACK ON HOW TO SOLVE THIS QUESTION WOULD BE MUCH APPRECIATED PLEASE SOLVE USING FORMULA SHEET THANK YOU IN ADANCED

Solution

An approach is to calculate the power in the wind.

P = (1/2)Av3

where is air density, A = area, and v = wind velocity.

Since power is force times velocity, the force is

F = P/v = (1/2)Av2

This assumes the air velocity is zero after hitting the wall, which obviously cannot be true because there would be a big localized increase in density and pressure. So there has to be a factor like the Betz factor for wind turbines.

So the force is now F = P/v = (1/2)Av2

So for a density of 1.341 kg/m3, A = 4*3=12 m2, and v= 125 km/h=34.72 m/sec,

So F = 9700 Kg m/sec2 = 9700 Newtons on a 1 m2 area