What has the Ottoman Empire to do with modern aviation?
So, what’s up with these fellows? And what has anything to do with the Ottoman Empire?
The main reason for winglets in commercial aviation is to save fuel. Aerodynamics teaches us that a perfect wing has as few “lift losses” as possible. Less wing tip vortex lowers the drag and gives better performance. Simplified – the basic cross section of the wing is more curved on the upper side, resulting in a higher air velocity, lower pressure and at the end – wing lift. If you can direct even more undisturbed air over the wing, the result is a more efficient wing.
A winglet can be traced back to NASA’s research in the seventies, when fuel prices suddenly sky rocketed. A winglet was found to reduce vortex (swirling air) at the wing tips giving better performance and fuel economy. Some wings are more suitable to winglets as others, and the design and effectiveness are often debated. I’ve only seen Scimitars on Boeing 737’s. A Scimitar winglet has an extra ventral strake, giving the whole construction a very distinct appearance. Most of the good stuff comes from the top portion of the winglet, but the ventral fin amplifies the effect.
The picture above shows a 737 wing fitted with Scimitar winglets that I took at Gardemoen, Oslo. The installation takes a couple of days and lengthens the wing span by about 20 cm and range about 65 Nm. Cost? Around 600.000 USD
Is it worth it? Fuel saving is said to be around 5% which equals to about 170.000 liters/year. Since the price of jet fuel has fallen by almost 40% the last 6 months, the incitement for retrofitting these devices has shrunk. However, these smart devices gives a long term effect on both investment and environment, so I’m sure they will keep on being popular even at a lower fuel price. These low fuel prices won’t last forever, so it might be a good idea to invest some of the saved money on fuel during “the good years”?!
Scimitar – Curved sword from the Ottoman Empire (see picture).
Article inspired by flyingmag.com