This discussion focuses on understanding the forces exerted by wind on a door, particularly when attempting to close it against strong winds. Key concepts include stagnation pressure, which is derived from Bernoulli's principle, and the impact of wind speed on force requirements. The pressure exerted by wind increases with the square of its speed, with a 10 mph wind exerting approximately 0.4 pounds per square foot, escalating to about 40 psf at 100 mph. The discussion emphasizes the importance of building tightness and airflow in determining the force needed to close a door against wind pressure.
PREREQUISITESEngineers, architects, and anyone involved in building design or wind load analysis will benefit from this discussion, particularly those focused on door mechanisms and structural integrity against wind forces.
It's not a very well thought out question. It depends on how fast the wind is blowing. I mild breeze blowing at 2 o4 3 kilometers/hour doesn't exert much force in comparison to wind that is blowing at, say, 120 km/hr.Bendimac16 said:Idk it just looks a dumb question just to see how much force i need to do
This is not the place to post personal theories.Bendimac16 said:So far, rn since i am making a theory
So, for instance, you are standing at your front door. The door is open and the wind is blowing into your house through the open door. The door opens inward. You are standing in the house and want to swing the door closed. You slowly push the door closed against the force of the wind. You want to know how much force is required to accomplish this.Bendimac16 said:how much force i need to do if the wind is strong to win it a close the door compared to normal
Wind will exert a force even on a static object, due to the change in momentum of the air particles, so no flow past the door is necessary. I remember from the days when we used Imperial units that the pressure exerted by a 10 mph wind on a flat surface was approx 0.4 pounds per square foot. It changes with the square of the wind speed, so will be approx 40 psf at 100 mph.russ_watters said:Note that how hard it is to close a door in the scenario above depends on wind speed, direction, and how "tight" or "leaky" the building is. If there's no leakage there's no airflow though the door and no force required.
What I believe @russ_watters is getting at is that if the rest of the house is tightly sealed then no wind will enter the front door. There would be no place for it to go.tech99 said:Wind will exert a force even on a static object, due to the change in momentum of the air particles, so no flow past the door is necessary. I remember from the days when we used Imperial units that the pressure exerted by a 10 mph wind on a flat surface was approx 0.4 pounds per square foot. It changes with the square of the wind speed, so will be approx 40 psf at 100 mph.
Yes, that's what I'm saying. And that makes it very difficult to model.jbriggs444 said:What I believe @russ_watters is getting at is that if the rest of the house is tightly sealed then no wind will enter the front door. There would be no place for it to go.