Investigation on Flapless Blended-Wing-Body Underwater Glider Based on Steady-Stream Active Flow Control

This study presents a novel flapless control system for blended-wing-body underwater gliders (BWB-VGs) based on steady-stream active flow control (AFC) technology. Through comprehensive computational fluid dynamics (CFD) simulations, we demonstrate that strategically placed AFC jets can effectively replace conventional mechanical rudders while significantly improving hydrodynamic performance. Our results show that at a jet-to-free-stream velocity ratio of 0.4, the AFC system generates pitch control moments equivalent to a 20° mechanical rudder deflection. The flapless design achieves a 25% reduction in drag and 15% improvement in lift-to-drag ratio compared to traditional rudder-based systems. Flow field analysis reveals the AFC system maintains superior flow attachment and reduces turbulent separation. By eliminating moving components, this approach enhances reliability while reducing acoustic signatures, offering promising potential for next-generation underwater glider development. The findings provide valuable insights for designing more efficient and robust underwater vehicles for oceanographic research applications.