Submarine Maneuvers Using Direct Overset Simulation of Appendages and Propeller and Coupled CFD/Potential Flow Propeller Solver

Abstract

This article presents two approaches to simulate maneuvers of a model radio-controlled submarine. In the direct simulation approach, rudders, stern planes, and propellers are gridded and treated as moving objects using dynamic overset technology. The second approach couples the overset computational fluid dynamics (CFD) solver and a potential flow propeller code, with both codes exchanging velocities at the propeller plane and wake, body forces, and propeller forces and moments, whereas rudders and stern planes are still explicitly resolved. It is shown that during the maneuvers, the range of advance coefficients does not deviate much from the design point, making a coupled approach a valid choice for standard maneuvering simulations. By allowing time steps about an order of magnitude larger than for the direct simulation approach, the coupled approach can run about five times faster. The drawback is a loss of resolution in the wake as the direct propeller simulation can resolve blade vortical structures. Open water propeller curves were simulated with both the direct propeller approach and the coupled approach, showing that the coupled approach can match the direct approach performance curves for a wide range of advance coefficients. Simulations of a horizontal overshoot maneuver at two approach speeds were performed, as well as vertical overshoot and controlled turn maneuvers at high speed. Results show that both CFD approaches can reproduce the experimental results for all parameters, with errors typically within 10%.

A mechanistic model of bubble entrainment in turbulent free surface flows

“…The entrainment model was implemented in the dynamic overset CFD code REX, which has polydisperse bubble transport capabilities. A brief summary is discussed next, but full details can be found in Castro and Carrica (2013a;2013b), Martin et al (2015), Li et al (2015), and references therein.…”

Numerical Simulation Study on the Effects of Course Keeping on the Roll Stability of Submarine Emergency Rising

“…Their work achieves the direct simulation of hull-propeller-rudder interaction by solving the unsteady RANS (URANS) flow about a submarine. In addition, Zaghi et al [24] applied dynamic overlapping grids to simulate the flow around a fully appended submarine, while Martin et al [25] adopted two approaches to simulate maneuvers of a radio-controlled submarine model, i.e., the direct simulation using dynamic overset technology and the coupled CFD/potential flow propeller solver. Regarding the study of rising stability of submarine using 6 DOF RANS solver, Mark et al [26] took the lead to employ CFD method to investigate the rising stability problem, and developed an unsteady 6 DOF RANS capability for simulating submarine rising maneuvers.…”

“…Meanwhile, considerable details about flow characteristics can be obtained through CFD methods with lower costs and higher accuracy, which provides insight into the physics of the problem. In light of the above advantages of CFD methods, various CFD simulation capabilities for submarine maneuvers had been developed by hydrodynamics researchers [20][21][22][23], especially the Reynolds Average Navier-Stokes (RANS) methods coupled with overset grid technology [24,25]. McDonald et al [20] provided a physics-based computational method for the trajectory prediction of the fully appended SUBOFF model with a propeller.…”

A DES-SST Based Assessment of Hydrodynamic Performances of the Wetted and Cavitating PPTC Propeller

“…A special class between the LES and the RANS approaches are the detached eddy simulation (DES) and delayed detached eddy simulation (DDES) methods, which combine the advantages of the two [14,15]. The main advantage of the viscous flow solution method is the possibility of a complete description of the flow features for a wide spectrum of applications, ranging from simple propeller analyses at both model and full scales [16][17][18] to self-propulsion in waves [19] or during maneuvers [20]. They can be relatively easy to apply for various problems such as ventilation of the propellers [21][22][23], oblique flow [24][25][26], wake analysis [27][28][29] and cavitation [30][31][32][33].…”