ROLLED-UP VORTEX DYNAMIC NUMERICAL STUDIES OF BIRD'S-BODY-TYPE FIGHTER

The fuselage type of a fighter greatly influences the aerodynamic characteristic especially in vortex generating which determines the agility and maneuverability. This paper elucidates the study of the vortex dynamics of a fighter with a bird's body type fuselage (BBTF), at constant canard deflection angle, using computational fluid dynamics (CFD). The CFD study employs Q-criterion to probe vortices and structured logarithmic grid to maintain the micro-gridding effectiveness of the turbulent boundary layer. The flow visualizations are coupled with shear-wall streamline to produce complete vortex dynamic pattern. The results show that the configurations of the bulky-head aerodynamic, the body, canard and main wing of the BBTF affect vortex core trajectories on the blended-body-main wing and the canard that very close to the surface, which gives higher coefficients of lift, of order 1.40 at a high angle of attacks causing its high agility and maneuverability. The numerical calculations show that there is no negative surface pressure distribution (SPD) on vertical walls near the canard and wings of BBTF fighters. On other design, negative SPD on vertical walls waste a lot of fuel energy, including weakening the lift coefficient.