HYDRODYNAMICS AND MANEUVERING SIMULATIONS OF A NON-BODY-OF-REVOLUTION SUBMARINE
Open Access
- Author:
- Poremba, John Edward
- Graduate Program:
- Mechanical Engineering
- Degree:
- Master of Science
- Document Type:
- Master Thesis
- Date of Defense:
- None
- Committee Members:
- Dr Eric G Paterson, Thesis Advisor/Co-Advisor
Dr Eric G Paterson, Thesis Advisor/Co-Advisor - Keywords:
- unsteady RANS
over set meshing - Abstract:
- Historically, physics-based predictions of the hydrodynamics and the rigid-body dynamics (six-degree-of-freedom trajectory, velocities and accelerations) associated with a maneuvering submarine is a challenging task. This is due to the tightly coupled nature of the fluid mechanics and dynamics of the vehicle, and the magnitude of the computational problem associated with resolving the hull, moving appendages, and propulsors. However, successful development and validation of a computational approach for simulating submarine maneuvering is important for understanding routine and emergency operations, and it can be used as part of the toolset in establishing a safe-operating envelope and for design and analysis of future undersea vehicles. In this research, the hydrodynamics and motions for a maneuvering submarine with a non-body-of-revolution hull form and X-stern control appendages are studied. The tightly coupled unsteady Reynolds averaged Navier-Stokes and six-degree-of-freedom (REL-TCURS) simulation tool, developed at the Applied Research Laboratory at Penn State, is used to perform time-accurate calculations for a series of basic maneuvers such as turning circles. For computational efficiency, REL-TCURS replaces control appendages and propulsors with body-force models, and it is shown that these models can be calibrated with fidelity models of the actual control appendages. The computational fluid dynamics model is validated through comparisons with force and moment data from steady wind tunnel experiment. The REL-TCURS simulations are compared to free-running model test data. While there is discrepancy in certain details of the rigid-body dynamics, which are attributed to uncertainty in the initial conditions and the vehicle mass properties, the REL-TCURS simulations resolve roll instability seen in the model, and are able to definitively link the instability to a sail/control appendage interaction. This result demonstrates the utility and importance of being able to correlate time-accurate hydrodynamics, with control surface and propulsor commands, and with resultant vehicle dynamics.