Dynamic diffusion of chaff cloud influenced by airflow surrounding the aircraft

This study reports the investigation of the diffusion and heat exchange characteristics of scattering chaff clouds within various flow fields around an aircraft. The poses and trajectories of each chaff were calculated by combining the random orbit model with the six degrees of freedom rigid body motion equations. The influence of the chaff rotation speed on its aerodynamics and heat transfer characteristics was considered and compared with reported results. Single chaff falling experiments were conducted in a wind tunnel to verify the reliability of the abovementioned methods, particularly the necessity to consider influences from the chaff rotation speed. A comparison of the dynamic diffusion process of the chaff cloud under different attack angles of aircraft and spreading device mounting positions revealed that diffusion was significantly influenced by the airflow around the aircraft. In contrast, the temperature variation of the chaff cloud was primarily driven by its intrinsic heating, with the angle of attack having a relatively minor effect.