Mathematical and Computational Fluid Dynamics Analysis of Low-Altitude Rocket Static Stabilityfor Various Fin Designs

Abstract

Rocket fins play an important role in determining theirstability during flight. The key characteristics that determine the static stability of a rocket are the relative positions of its centre of gravity and centre of pressure.Determining the centre of gravity is rather simple. However, determining the centre of pressure is more challenging as it depends on the pressure distribution over the surface of the entire rocket body. The present study analyses the static stability of a low-altitude rocket with various fin designs.The parameter used to measure the aerodynamic stability of the rocket is the static margin, Me.Mathematical predictionsusing Barrowman equations and computational fluid dynamics(CFD) were employed to obtain data for the centre of pressure and centre of gravity. The data from both approaches was then compared and analysed. The Barrowman equations were shown to provide support for the computational fluid dynamicsdata, indicating that the static margin is determined by the centre of pressure. However, there are differences in terms of the observed trend.