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Space Shuttle: Difference between revisions
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→Longitudinal Dynamics
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[[File:Control response.gif|500px|Pitching CM moment]] | [[File:Control response.gif|500px|Pitching CM moment]] | ||
As seen from the figure, at high Mach numbers the response is fairly flat (i.e. large elevon deflections are needed to control the Shuttle) and also non-linear (upward deflections cause much less pitching moment than downward deflection). In contrast, at low Mach numbers small elevon deflections already cause large moments. In all regimes, the pitching moment is normal force (i.e. AoA) dependent. | As seen from the figure, at high Mach numbers the response is fairly flat (i.e. large elevon deflections are needed to control the Shuttle) and also non-linear (upward deflections cause much less pitching moment than downward deflection). In contrast, at low Mach numbers small elevon deflections already cause large moments and the response is almost linear. In all regimes, the pitching moment is normal force (i.e. AoA) dependent. | ||
Since the elevons supply both pitching and roll control, at high hypersonic Mach numbers roll controls are close to being saturated with elevons deflected near full up. To open up better roll control, below Mach 10 the speedbrake is opened to provide a pitching moment relieving the elevons, and the Shuttle's body flap can also be trimmed upward. | Since the elevons supply both pitching and roll control, at high hypersonic Mach numbers roll controls are close to being saturated with elevons deflected near full up. To open up better roll control, below Mach 10 the speedbrake is opened to provide a pitching moment relieving the elevons, and the Shuttle's body flap can also be trimmed upward. | ||