We live in an amazing century, a century of technology. Internet, computers, television, mobile phones, cars, planes and so on. Everything to make your life easier. But it enables us to see the world as well. You can enter a metal tube in London and 8 hours later get out anywhere you whould like. For me this is still a miracle and so it is for a lot of passegers because I often get asked the question how a plane flies…. Soo, how does a plane fly?
It got everything to do with a wing moving through a mass of air and when this air flows over the wings, magic happens. In this post I will try to explain you a bit about what this magic actually is.
Every object on earth is pulled towards the centre of the earth by a force called gravity. To get a plane in the air, we need another force, working in the opposite direction as gravity and this force we call: lift… all we need is a bit more lift force than gravity force and we will fly.
To understand what creates this lift, I will first tell you something about the thoughts of one important man, sir Daniel Bernoulli. He didn’t know it when he was alive, but his theory played a mayor role in how a plane can fly.
Bernoulli discovered that when a mass of air or fluid accelerates, the pressure in this fluid will decrease. This said, if you look at the profile of a wing (picture below). You can see that the upper part of the wing is bend more than the bottom part, because of this the upper airflow wil have to travel a longer distance in the same amount of time, which means that the upper airflow will accelerate and so the pressure on the upper side of the wing will decrease. This decrease will create a pressure difference between the upper and the lower surface of the wing. We all know that any substance will want to flow from high pressure to the low pressure. So this tendency will create a upward force: lift! And the faster the plane flies through the air, the more lift the wings creates.
When a plane takes off, it accelerates to a certain calculated speed, dependent on lots of different factors, like weight, windspeed, temperature, density etc. This is the speed that the wings create the perfect amount of lift, to lift the plane off te ground. For the particular plane that I fly, this happens at about 120-145 knots (200-230 km/h). Magic happens and there we go, off to our destination.
This was my first flying for dummies post, I hope you liked it. Next time I will tell you what other factors effect this liftforce.