Dynamics modeling and simulation of a saucer-shaped super-pressure aircraft

In the recent years, a new concept of saucer-shaped super-pressure aircraft (S3PA) has been noted for its widespread application prospect such as stratospheric platform, low-attitude transportation especially for heavy lift, etc. Many pre-studies on these conceptual aircraft have been carried out in several countries, and various kinds of prototypes has been designed and manufactured. This paper focuses on the dynamics modeling and simulation of a prototype vehicle of S3PA, which is built by Academy of Opto-Electronics, Chinese Academy of Sciences. The 6 degrees of freedom (DOF) dynamic model is established first. After that, particular models of forces on this prototype vehicle are focused on, while the aerodynamics and added mass difference between this type of aircraft and traditional aerostat are indicated. The gravity and buoyancy model and thrust force model are easily built. Considering there is no plane of symmetry in horizon, the aerodynamic coefficient is no longer symmetric to zero angle of attack, which is different from common vehicles. Meanwhile, in order to solve the lack of lateral CFD aerodynamic data (for sideslip angle), a new coordinate transform method is adopted for convenient of calculating aerodynamic force. The added mass estimation for this vehicle is then given based on empirical formulas. With all the models, a 6DOF dynamic model is established based on MATLAB/Simulink. Simulation in a simple trimmed condition is obtained, and preliminary cognition of flight characteristic is acquired.