Power drive (29): anti-flutter cross band

February 14, 2020

In accelerated flight, many sails flutter at the leading edge, especially those with large cells. Ozone prevents this mechanically with a tape sewn across. A vertically placed fabric band in the leading edge should prevent the lower sail from fluttering. // Source: Paragliding Academy, edited A current trend in paraglider construction means: Models with improved performance are also in demand in the A-glider sector. However, there is a problem in this umbrella class. A-screens are typically built with a small number of cells and thus relatively large cells. In addition, the cross-tension of the umbrellas is reduced compared to higher-class models in order to achieve a softer folding behavior. However, if you then step on the accelerator and pull the front down, the sail tension at the leading edge can decrease further as the speed increases. This results in a disturbing effect: the loose fabric of the sail begins to flutter at the leading edge. And that's a real performance killer for accelerated flight. To prevent this, you could increase the number of cells and also increase the sail tension, whereby you can quickly reach the limits of the A-Class. Ozone has taken a different route with its new EN-A wing Mojo 6. As in the predecessor, the cell number was left at 40. But there is now a fine detail at the leading edge: A narrow cross band made of normal paraglider fabric is sewn in at the bottom, which sits at a right angle to the bottom sail. With this orientation, according to Ozone, it is supposed to prevent the bottom sail from mechanically and very effectively preventing it from fluttering and fluttering. At the same time, the cross section of the inlet openings is practically not reduced, and the filling behavior of the screen is not significantly influenced. Similar solutions for reducing the tendency of a lower sail to flutter have been around for a long time. Typically, the bottom sail is sewn up once at the leading edge so that it lies there twice. It then forms a kind of pocket that is ventilated from behind and thus stabilizes the leading edge. BGD, for example, advertises such a feature in the new EN-C Cure 2 as a "Double Skin Leading Edge". The new variant of Ozone with the vertical anti-flutter cross band should mechanically represent the more effective flutter brake, especially with large cell cross-sections. From performance to promotion urge Lu-Glidz repeatedly takes up current technical developments and details with which the paraglider manufacturers try to further improve the performance of the paragliders. If you like such information and you want to be provided with such in-depth reports and explanations in the future, then become a sponsor of Lu-Glidz. Whether once, occasionally or as a quasi-subscriber by regular order - everything is allowed and possible. Even the funding amounts are freely selectable. The processing is very simple via Paypal. Those who prefer a classic bank transfer or even the establishment of a standing order can transfer the desired amount to the following account: Recipient: Lucian Haas, Breite Strasse. 54, D-53111 Bonn IBAN: DE71 3807 0724 0361 6828 00 BIC: DEUTDEDBXXX Purpose (please specify): "Subsidy Lu-Glidz" Thank you!

allemand
This article has been translated for your convenience and was originally written in allemand.

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