Flight dynamics
Ali Jafarian; Saeed Sarkheil; Vahab Haghighat
Abstract
In this paper, the computational fluid dynamics simulation of a tactical aerostat is conducted and the longitudinal static coefficients of the aerostat are evaluated. In this simulation, Fluent software and Spalart- Allmaras turbulent model are used. First, in order to validate the numerical method and ...
Read More
In this paper, the computational fluid dynamics simulation of a tactical aerostat is conducted and the longitudinal static coefficients of the aerostat are evaluated. In this simulation, Fluent software and Spalart- Allmaras turbulent model are used. First, in order to validate the numerical method and the applied turbulent model, a famous airship hull is simulated and the drag coefficient at zero angle of attack is compared with the references and the CD0 is in very good agreement with references. Then, the designed aerostat is simulated in the angle attack of )-10 to 30( degrees then the pressure, Y+ contours and the streamlines around the aerostat are presented. Furthermore, the aerodynamic longitudinal coefficients are calculated for 5 and 20 m/s. The results show that the aerodynamic coefficients do not vary significantly with the change of velocity and the pitch moment coefficient about the nose of the designed aerostat has a negative slope. Finally, Comparing the pitch moment coefficient of the designed aerostat with two American and Korean aerostats indicate that, the designed aerostat has more static stability.
