Numerical investigation of the effect of aerodynamic characteristics on flight simulation of a subsonic rocket

In recent years, the use of rocket designs in civil and military fields has increased gradually. Studies in this field have focussed on more efficient design methods to improve flight performance and controllability. Flight time is a critical parameter in rocket designs. This parameter is largely dependent on the aerodynamic performance of the vehicle. The most important elements that determine aerodynamic performance are nose cone and fin designs. The proper design of these components directly affects the stability and manoeuvrability of the rocket. In addition, speed and angle of attack have a significant effect on the flight performance of the rocket. Increasing speed and angle of attack cause significant changes in aerodynamic parameters, which makes the controllability of the rocket difficult. In this study, a two-stage method is adopted for model rocket design. In the first stage, a rocket model was created using OpenRocket software and aerodynamic performance analysis was performed based on the Barrowman method. Within the scope of this analysis, the lift coefficient (Cl), moment coefficient (Cm) and drag coefficient (Cd) values of the rocket were calculated for a given speed and angle of attack. Based on the data obtained, the three-dimensional design of the model was realised in CAD environment. In the second stage, the aerodynamic performance of the rocket was calculated by using OpenFOAM, an open source continuous environment mechanics simulation programme. Simulations were carried out at flow velocities of 200, 250 and 303 m/s and angles of attack of 0° and 10°. In addition, the aerodynamic parameters were analysed by considering 254 m/s velocity and 0° angle of attack in the simulations performed in OpenRocket software, and the results obtained were compared with OpenFOAM data. The results of the analyses show that there are significant changes in the aerodynamic parameters of the rocket with the increase in speed and angle of attack. In particular, the increase in velocity caused a significant increase in the drag force, which made the controllability of the rocket difficult. Similarly, the increase in the angle of attack caused instabilities in the lift and moment coefficients, which adversely affected the flight stability. At the end of the study, it was observed that designs suitable for different speeds and angles of attack should be developed and that it is important to subject these designs to extensive numerical tests before proceeding to the production phase. This research aims to contribute to the design processes for improving aerodynamic performance by providing a systematic approach in the field of model rocket design.