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Icaro Laminar 13 MRX: Difference between revisions
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→Composition of the total moment: Moment coefficient versus absolute moment
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==== Moment coefficient versus absolute moment ==== | |||
The use of the moment coefficient instead of the absolute moment offers several advantages, including comparability, scalability, and simplified mathematical analyses. The moment coefficient allows for a better description of the aerodynamic properties and behavior of aircraft, making it an important tool in aerodynamics and aircraft design.<br> | |||
The moment coefficient is closely related to the lift coefficient and is often used to assess flight behavior. In particular, the moment coefficient describes how strongly an aircraft responds to a change in the angle of attack.<br> | |||
The moment coefficient is dimensionless. This makes it easier to compare the stability and behavior of different aircraft, regardless of their size or weight. The absolute moment, on the other hand, depends on specific units, which makes comparisons more difficult.<br> | |||
The moment coefficient can be used under various flight conditions (such as speed and air density) to characterize an aircraft's behavior. Since it is defined relative to other quantities (lift, speed), it remains consistent even when conditions change.<br> | |||
The moment coefficient is defined as follows:<br> | |||
CM = M / (0.5 * ρ * V² * S * c)<br> | |||
where: | |||
* M is the absolute moment about the center of gravity, | |||
* ρ is the air density, | |||
* V is the aircraft's speed, | |||
* S is the wing area, | |||
* c is the average chord length of the wing.<br> | |||
The above is applicable to normal aircraft with rigid wings and a fixed center of gravity. | |||
For flexible hang gliders with weight-shift control, the moment coefficient is additionally dependent on the wing loading (due to wing deformation) and the current center of gravity location. When comparing the moment coefficients of different hang gliders, it must therefore be ensured that the wing loading level (airspeed) and the center of gravity position are identical.<br> | |||
''Comment: Due to the dependence of the moment on the load factor, the moment is measured at different speeds for the certification of hang gliders. Different certification limits are defined for each speed.'' | |||
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==== The moment diagram for hang gliders ==== | |||
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[[File:Pitching moment depending on the pilot position.jpg|none|thumb|800px|Influence of pilot deflection on pitching moment]] | [[File:Pitching moment depending on the pilot position.jpg|none|thumb|800px|Influence of pilot deflection on pitching moment]] | ||
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=== Tuck avoidance === | === Tuck avoidance === | ||