Expenimental study on the trajectory of a projectile penetrating the air-water interface

• Main Author: 曾獻田
• Other Authors: 謝傳璋
• Format: Others
• Language: zh-TW
• Published: 2002
• Online Access: http://ndltd.ncl.edu.tw/handle/73108253420144775509

碩士 === 國立臺灣大學 === 造船及海洋工程學研究所 === 90 === The subject of this paper is to study the trajectory of the projectile penetrating the air-water interface and analysis its stability experimentally. In theoretical part, firstly, we derive the fundamental of the experiment and the dynamic relation between the model and projected projectile. Secondly, the theoretical trajectory of the center of gravity of the model projectile is computed. In experimental part, the projectile is projected by air pressure and free fall. The experiment is conducted in NTU-NAOE towing tank. Two CCD cameras were setup, one is above and the other is under water surface, respectively, to record the trajectory of the projectile. After analyzed the trajectory of the center of gravity, pitch angle, and attack angle, the result was compared with the computed data Generally, from the comparison and the experiment result we find that the projectile is stable when the projectile angle is 20, 25, and 30 degree, and the speed is within 4~10 m/s.