Parachute opening process and stable descending stage resistance area obtaining method

Abstract

The invention relates to a parachute opening process and stable descending stage resistance area obtaining method, and belongs to the field of aerospace pneumatic deceleration. The method comprises the steps: 1, enabling a parachute storage cabin to do falling motion; 2, continuously shooting n pictures in the parachute opening process of the parachute through a camera; 3, counting the pixel number Ni of the maximum projection area of the parachute in the image shot at the ti moment; 4, converting the maximum projection area to a position which is L1 away from the camera according to the areacorrection proportionality coefficient ksp; 5, calculating a correction area Si of the maximum projection area; 6, calculating the resistance area CDSi in the parachute opening process; obtaining a change curve of the resistance area in the parachute opening process; similarly, calculating the resistance area CDSj and the average resistance area CDS in the parachute stable descending process. According to the method, the projection area of the parachute in the parachute opening process is calculated through camera shooting, the change rule of the resistance area of the parachute in the parachute opening process is obtained, and calculation of the resistance area of the parachute in the parachute stable descending process is also achieved.

Description

technical field [0001] The invention belongs to the field of aerospace aerodynamic deceleration, and relates to a parachute opening process and a method for acquiring a resistance area during a steady descent stage. Background technique [0002] In the aerospace field, the parachute is an important aerodynamic deceleration and stabilization device. The parachute is made of soft and breathable special spinning material. After the parachute is inflated, it has a large resistance area, which can greatly reduce the movement speed of the object, and can also provide stability for the object with resistance. [0003] At present, in wind tunnel test, high tower drop test, and airdrop test, the resistance area is generally calculated by the parachute recovery weight (load) and the speed when the parachute falls stably. During the field launch test, the measured parachute steady descent speed is generally obtained by GPS measurement or high-speed camera. It is the speed of the parac...

AI Technical Summary

Problems solved by technology

However, it is difficult to ensure no wind in the external environment, and the stable falling speed of the parachute system is generally less than 10m / s, which is easily disturbed by the wind field. When the steady falling speed of the parachute system is smaller, it is more affected by the wind field

[0004] At present, the change law of the resistance area of ​​the parachute in the parachute opening process is generally given by the empirical formula, but the change law of different umbrella types and different parachute opening conditions is not completely consistent. The change of the resistance area given by the empirical formula may be Introduce additional error to the load calculation of the parachute opening process

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