Session: 06-14-03 Underwater Vehicles and Design Technology III

Paper Number: 80537

80537 - Relevance of VPMM: A Survey, Conundrum and Conclusions 

The work of [1] shows that the 6DOF lumped parameter model for maneuvering of underwater crafthas been well defined and accepted. The hydrodynamic coefficients used in such models are classifiedas restoring coefficients, damping coefficients and added mass coefficients. There is minimal tono clarity on the method used to obtain added mass and damping coefficients as discussed in [2].There is uncertainty associated with the hydrodynamic coefficients used in lumped paramter modelsas discussed in [3]. The method proposed in this abstract ensures consistency in the evaluation ofadded mass and damping coefficients, by using a viscous flow solver for both. Alternative methodssuch as [4] calculate the added mass terms by using simplified potential flow based theory andsteady state simulations. While the refinement of coefficients has been discussed in [5] using acombination of VPMM and steady drift data, this paper discusses the applicability of purely dragor PMM tests depending on the slenderness of the craft. This method is performed of two crafts of various slenderness ratios. Coefficients are obtained for each craft using pure VPMM simulationsfor sway and yaw on both planes. Coefficients are also obtained using pure steady state tow tanksimulations at a set of hull offset angles. The use of viscous RANS simulation data makes it possibleto include flow straightening effects due to fins at various angles of deflections shown in [6]. LPMmaneuvers with these sets of coefficients are compared to a RANS based simulation of the sameunsteady maneuver. Since unsteady maneuvers highlight the importance of added mass coefficients,such a comparison yields clarity on the applicability of VPMM to understand the maneuvering of acraft of given L(length)/D(diameter) ratio. Such a comparison is done through steady state maneuverssuch as turn circle maneuver and unsteady maneuvers such as zigzag. It is observed that the mostslender craft is modelled well using steady drift data in the absence of VPMM with an estimation ofadded mass terms using numerical methods such as [7].

KeywordsManeuvering·Unsteady Hydrodynamics·Underwater vehicles·

References

[1]Robert F. Roddy. Investigation of The Stability and Control Characteristics of Several Configurations of the DARPASUBOFF Model from captive-model experiments. Technical report, David Taylor Research Center, Bethesda, MD,1990.

[2] Bruno M Ferreira, Anıbal C. Matos, and Nuno A. Cruz. Modeling and control of TriMARES AUV. pages 1–6.

[3]Justin T Kleiber, Lakshmi M Miller, Stephen Krauss, Daniel J Stilwell, and Stefano Brizzolara. Assessing theEffect of Hydrodynamic Parameter Uncertainty on AUV Performance with Gaussian Processes. InOceans 2021Technical Proceedings, 2021.

[4]J. Ezequiel Martin, Thad Michael, and Pablo M. Carrica. Submarine maneuvers using direct overset simulation ofappendages and propeller and coupled CFD/potential flow propeller solver.Journal of Ship Research, 59(1):31–48,2015.[5]Taylor Njaka, Lakshmi M Miller, Stefano Brizzolara, and Daniel J Stilwell. Method for Improving ExistingManeuvering Models to Accomodate Large Drift Angles. InGlobal Virtual Oceans, 2020.

[6]Taylor Njaka, Stefano Brizzolara, and Daniel Stilwell. CFD investigation of Hull-Rudder interaction for improvedmaneuvering models. InSNAME Maritime Convention 2019, SMC 2019, 2019.

[7]M E Kepler, S Pawar, D J Stilwell, S Brizzolara, and W L Neu. Assessment of AUV Hydrodynamic Coefficientsfrom Analytic and Semi-Empirical Methods. InOCEANS 2018 MTS/IEEE Charleston, pages 1–9, 10 2018.

Presenting Author: Lakshmi Miller Virginia State and Polytechnical University

Authors:

Lakshmi Miller Virginia State and Polytechnical University
Taylor Njaka Virginia State and Polytechnical University
Stefano Brizzolara Virginia State and Polytechnical University