This study investigates the effect of a forward hydroplane configuration on flow characteristics around a submarine, with a particular focus on vortex dynamics, wake development, and turbulence intensity at the propeller plane. While previous investigations have offered broad insights into hydroplane performance, this work delivers a targeted comparative analysis of two specific configurations—sail plane and midline plane—relative to a baseline case without hydroplanes, thereby addressing a notable gap in the literature. Utilizing a validated SUBOFF model, both experimental measurements and computational fluid dynamics (CFD) simulations were conducted at pitch angles of 0° and 15° to evaluate the hydrodynamic consequences of hydroplane placement. Principal findings indicate that the sail plane intensifies flow non-uniformity, increasing sail wake thickness by up to 2.5-fold and raising turbulence intensity at the propeller plane by 13.8%, compared to 12.2% for the midline plane. Quantitative analysis reveals a 5% reduction in drag coefficient and a 23% decline in peak vorticity for the midline plane configuration compared to the sail plane. At a 15° pitch, the midline plane exhibits superior performance by attenuating the crossflow vortex (resulting in a 33% reduction in vorticity) and delaying boundary layer separation; however, its advantages are less significant at zero pitch. This study provides practical guidance for submarine design, highlighting the trade-offs between hydroplane configurations and their operational implications, particularly under maneuvering conditions. The results highlight the midline plane’s ability to mitigate detrimental vortex interactions, providing a viable approach to enhanced hydrodynamic efficiency and reduced propeller-induced vibration and noise.
Rahmani et al. (Tue,) studied this question.