Numerical Investigation on Flow Characteristics of Serpentine Nozzle with Internal Bump

To address flow separation issues in compact serpentine nozzles with small length-to-diameter ratios, this study proposes a free-form deformation (FFD)-based design method incorporating internal bumps. CFD analysis shows the optimized design reduces adverse pressure gradients, suppressing flow separation while improving performance. For a serpentine nozzle with a length-to-diameter ratio of 1.8, thrust and discharge coefficients increase by 1.8% and 5.2% respectively. Even for a serpentine nozzle with a length-to-diameter ratio of 2.25, shows 0.3 and 0.8% improvements, approaching conventional axisymmetric nozzle performance. The design enables better integration of serpentine nozzles in compact aircraft layouts while preserving stealth advantages.