Electronic Measuring System Applied to the Trajectory Analysis of the Water-Propelled Rocket

• Main Authors: Shih-Siang Cheng, 程智祥
• Other Authors: none
• Format: Others
• Language: zh-TW
• Published: 2004
• Online Access: http://ndltd.ncl.edu.tw/handle/72995454979740022564

碩士 === 逢甲大學 === 航空工程所 === 92 === The purpose of this paper is to propose a practical way to compute the accurate trajectory of the water-propelled rocket at any given firing angles. The maximum velocity and drag coefficient have to be known before solving the equations of motion of the water-propelled rocket. Then, a set of velocity measuring system equipped with an electronic sensing timer and a compatible launching device is developed to measure the maximum velocity of the water-propelled rocket under various combinations of water volumes and air pressures .Another system equipped with the same electronic sensing timer is designed to obtain the drag coefficient of zero-angle-of-attack of the water-propelled rocket. The drag coefficient is verified by a vertical launching test. The trajectories and ranges of the water-propelled rocket under various combinations of water volumes and air pressures are calculated by MATLAB coding program. The calculated results should be corrected by the firing data and the correction factors (so-called form factors) are generated. Form factor is actually the function of firing angle, and three from factors at three specific firing angles are found in this research. Finally, the trajectories and ranges of the water-propelled rocket at any given firing angles can be calculated with their form factors obtained by linear interpolation criteria.