Numerical Study on the Water Takeoff Performance of Unmanned Seaplane

Abstract

The research on the water takeoff performance of unmanned seaplane is of great significance to its overall optimization design and taxiing stability control system. This paper proposes a new numerical method for solving the water takeoff performance of unmanned seaplane. The aerodynamics and hydrodynamics are solved separately by decoupling solution principle. The influence of aerodynamic force and moment, engine thrust and moment on hydrodynamic force and taxiing attitude is considered synthetically by the vertical approximate balance hypothesis and instantaneous pitch balance hypothesis. The discrete velocity piecewise solution is used to solve the takeoff process. The results show that the taxi resistance peak appeared in the range of 0.3~0.35 times of takeoff velocity, and the greater is the trim angle, the smaller are the hydrodynamic resistance and hydrodynamic moment when the unmanned seaplane taxiing at medium or high speed. What's more, compared with the fixed trim angle hypothesis, the combined trim angle method is more consistent with the actual takeoff process.