Experimental Study of Dynamic Stability for a Entry Capsule in Supersonic Flow

Due to the lack of existence of control surfaces in entry capsules, the subject of static and dynamic stability is always important. In this paper, these coefficients are investigated experimentally for the case of forced oscillation at supersonic flow. In this experimental study, the effects of freestream Mach number, mean attack angle and pitch frequency on dynamic stability coefficients were evaluated. According to the results, in Mach 1.8, the geometry starts to be dynamically unstable. One approach to overcome this problem is to change the average attack of angle of the model. This change in the mean attack of angle, similar to the results presented for the five-degree mean angle, will lead to dynamic stability.