| Summary: | Rocket fins play crucial role in ensuring the rocket stability, but they also cause an undesirable effect known as drag, which primarily stems from skin friction and pressure drag. Skin friction drag is caused by the friction of the viscous flow of air around the rocket, while pressure drag is caused by the air being forced around the rocket. The present study analyses the total fin drag of low-altitude rockets with various fin configurations, employing mathematical prediction and computational fluid dynamics (CFD) to obtain comprehensive data for the total fin drag and full body drag. The findings from both approaches were then compared and analysed. It was discovered that drag increases approximately linearly with the fin's semispan within the studied range, although the effect of fin thickness is comparatively smaller, especially for shorter fins. The fin drag is empirically correlated with both the fin semispan and thickness. Furthermore, despite the noticeable discrepancy in the drag magnitude predicted by both approaches, the OpenRocket software has shown to predict the trend well. The correlations demonstrate remarkable agreement when compared to CFD data, with the highest root mean squared error of 0.3%. Therefore, it is now possible to correct OpenRocket data to significantly more accurate values without having to conduct Computational Fluid Dynamics analysis.
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