Off Topic — HabitableZone

Off Topic

EMILY musings

I have heard arguments about the destructive force caused by hurricanes and tornadoes, some people say that the roof of a house can be ripped off by the rapid drop in the pressure of the air above the roof, some people say that the wind or air pressure is so strong against the surface that it can rip the roof off.

I suspect that it is partly due to both effects. Something similar to the flowing air against an airplane wing.

I looked at the progress of hurricane EMILY, the wind speed was 115 miles per hour and the minimum pressure was 27.82 inches of mercury.

Assuming that the normal pressure at sea level is 30 inches of mercury. Then the pressure difference is more than two inches of mercury.

Standard atmospheric pressure is 14.70 psi and 27.82 inches of mercury equals 13.66 psi therefore there is a pressure difference of 1.4 psi. .

If there is a house with an internal area of 1500 sq.ft., then the area in question has 216.000 sq. inches and the pressure difference for that area will be 224640 psi. Assuming that the internal pressure remains at the standard pressure.
I do not know how much a roof of a 1500 sq. ft. house weighs but I suspect that it is less than 224640 lb.

The highest recorded atmospheric pressure, 108.57 kPa (1085.7 mbar or 32.06 inches of mercury), occurred at Tonsontsengel, Mongolia, 19 December 2001
The lowest recorded non-tornadic atmospheric pressure, 86.996 kPa (869.96 mbar or 25.69 inHg), occurred in the Western Pacific during Typhoon Tip on 12 October 1979

Just some thoughts.

Log in or register to post.

The whole thread (3 posts)