DIHEDRAL ANGLE
Another basic component of fight stability is called DIHEDRAL ANGLE, which in airplane design refers to the angle at which the wings are attached to the body of the aircraft. Take a look at Figure 8. If the wings are angled upward from horizontal, they are aid to have POSITIVE DIHEDRAL ANGLE. If wings are angled downward from horizontal they are said to have NEGATIVE DIHEDRAL or ANHEDRAL ANGLE.Positive dihedral helps put the center of lift above the center of gravity, creating a self-correcting mechanism. If the plane rocks to one side, for example, the center of gravity will tend to rock back to vertical. The price for a self-correcting aircraft with positive dihedral angles is a little more drag and a little less lift. Flying is series of negotiations with forces. For passenger planes in particular, the added stability is worth a little less efficiency. detikgaming daftar sbobet88
SCALE EFFECTS
Full-sized passenger aircraft and paper airplanes manipulate airflow in different ways. I was able to exploit how the air flow changed on my plane at varying speeds to break the world record. This strategy wouldn't work on a huge 747-sized plane, though. The dramatically shifting air flow on the paper airplane wing is a product of SCALE EFFECTS. Scale effects work like this: Air molecules don't change size or properties. They stay the same, regardless of the wing's size. So when you scale down a 747's gently curving wing to paper airplane size, the air molecules are now making a very sharp turn over a very short distance-just like the race cars in Figure 9 on page 11. Here's the important concept: there's a limit to how sharp a turn air can make around a fast moving object--whether that's a 747 or a paper airplane. There's a whole set of numbers, known as Reynolds numbers, that precisely quantify this idea; these numbers measure the ratio of the inertial forces to the viscous forces in a liquid or air.
Reynolds numbers allow aerodynamicists to make half-size or quarter-size wings to test in smaller facilities so, for example, they don't have to have a humungous building to test a full-size 747. What does this mean for paper airplanes? It's better to have a flat, rather than curved wing, so the airflow will be more consistent (and not have to make a sharp turn around a tiny curved wing). detikgaming game slot online terbaik
During changes in speed, the small wings of a paper airplane can see dramatic shifts in airflow from front to back. The same shift would be much smaller proportionally on a full-sized airplane wing, since the curving is much less abrupt for air molecules on a big wing.
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