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Icaro Laminar 13 MRX: Difference between revisions
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→Impact of gusts on pitch-stability
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On the next slide, the influence of the gust on the airflow is shown quantitatively. Two different gust strengths (5m/s and 10m/s) are examined for an airspeed of 40km/h (11m/s, approx. trim speed, left diagram) as well as for a very high airspeed of 100km/h (approx. 28ms, right diagram) | On the next slide, the influence of the gust on the airflow is shown quantitatively. Two different gust strengths (5m/s and 10m/s) are examined for an airspeed of 40km/h (11m/s, approx. trim speed, left diagram) as well as for a very high airspeed of 100km/h (approx. 28ms, right diagram). | ||
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The gust direction is plotted on the x-axis. The angle is defined in relation to the undisturbed direction of the airflow. | |||
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The orange curve describes the change in angle of attack Δα induced by the gust (left y-axis). | The orange curve describes the change in angle of attack Δα induced by the gust (left y-axis). | ||
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The blue curve shows the influence of the gust on the inflow velocity. This is best represented by the ratio of the dynamic pressure of the disturbed flow velocity to the dynamic pressure of the undisturbed velocity (right y-axis). The idea behind this is that the absolute air forces and the absolute momentum scale linearly with the dynamic pressure (P<sub>dynamic</sub> = 1/2*density*velocity<sup>2</sup>). This means, for example, that a doubling of the free flow velocity due to a gust leads to a 4 times higher air force and moment. Therefore, this representation is more meaningful than the application via the velocity ratio. The value is just the factor by which the undisturbed air force and the moment must be multiplied to obtain the new values with gust. | The blue curve shows the influence of the gust on the inflow velocity. This is best represented by the ratio of the dynamic pressure of the disturbed flow velocity to the dynamic pressure of the undisturbed velocity (right y-axis). The idea behind this is that the absolute air forces and the absolute momentum scale linearly with the dynamic pressure (P<sub>dynamic</sub> = 1/2*density*velocity<sup>2</sup>). This means, for example, that a doubling of the free flow velocity due to a gust leads to a 4 times higher air force and moment. Therefore, this representation is more meaningful than the application via the velocity ratio. The value is just the factor by which the undisturbed air force and the moment must be multiplied to obtain the new values with gust. | ||
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