Reynolds Effects on Submarine Stern Plane Efficiency and Stall using Wall-Resolved CFD

This paper studies the forces and moments and flow around the well-known BB2 generic submarine hull form, in manoeuvring conditions at Reynolds numbers ranging from model-scale to full-scale. Calculations are performed for a range of drift angles and rotation rates, to establish the scale effects on the loads on the complete submarine, but in particular on the control surface loads. The results of the simulations show that there are Reynolds effects on the loads. The origin of these Reynolds effects are the loads (lift and drag) on the aft hydroplanes. To quantify the consequences of the scale effects, the resulting forces and moments are post-processed in two ways: by deriving the horizontal stability indices and deriving coefficients for Reduced Order Models (ROMs). With these ROMs, manoeuvres are simulated. This demonstrates the effect of the Reynolds number on the course keeping and turning abilities.