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Calculus of hypersonic polar curves for re-rentry spacecraft using the Newton's theory

Gourinat, Yves and Delente, Edouard and Pasquier, Aurélie Calculus of hypersonic polar curves for re-rentry spacecraft using the Newton's theory. (2001) In: 52th International Astronautical Congress, Oct 2001, Toulouse, France .

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Abstract

The old assumption formulated by Newton for fluid mechanics theory assumed that dragobstacle resulted only from dynamic shock of independant particles, with dynamic pressure affected of angular kinetik incidence ratio. This assumption having proved to be wrong in classical fluid dynamics, Newton gave it up. But when the flow is constituted of free particles, this type of calculation appears to be valid : in rarefied gases, and in hypersonic configuration. This observation leads to educational illustration based on very simple collision equation applied to surfaces, integrated on simple shapes. The students build Excel sheets and Maple programs allowing calculation of shape-ratios and effective sections for a plate, cylinder and cone. The main problem is here to restitute the hidden surfaces in flow. This calculation is used to generate the hypersonic polar curve by determination of lift and drag for each angle of attack. After this validation, the students calculated (with the same process) the shape of Atmospheric Reentry Demonstrator. In the frame of cooperation with EADS Launch Vehicle, conducted by the students, the curve was compared with ESA actual polars. The difference is in the range of 15% for operational angles of attack (where shield shape is globally in front). The students then conclude that this very simple approach (elementary kinetics, without thermics) provides a correct range of values, in spite of limitations for high angles of attack.

Item Type:Conference or Workshop Item (Paper)
Audience (conference):International conference proceedings
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Institution: Université de Toulouse > Institut Supérieur de l'Aéronautique et de l'Espace - ISAE
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Deposited By: Yves GOURINAT

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