Twenty-Fourth Symposium on Naval Hydrodynamics (2003) / Chapter Skim
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Validation of Control-Surface Induced Submarine Maneuvering Simulations Using UNCLE
Validation of Control-Surface Induced Submarine Maneuvering Simulations Using UNCLE
Pages 624-639
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From page 624... ...
The key requirement for maneuvering simulations is accurate prediction of the forces acting on the hull, propeller and control surfaces. Current techniques treat the forces and moments as functions of the motion state variables and their derivatives md approximate them using truncated Taylor series expansions often containing second, third and cross derivative terms (Boger, 1997~.
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From page 625... ...
(2) 1 1 2 Here, A_3f lOq is the inviscid flux Jacobian, A-is defined by A- = SASSY, where S is the matrix of right eigenvectors of A, A- is a diagonal matrix containing the negative eigenvalues of A as nonzero elements, and the overbar denotes a Roe average.
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From page 626... ...
The convective terms and dissipative terms are computed in a manner analogous to the corresponding terms in the mean flow solver. The turbulence model is loosely coupled, implying that the mean flow and two-equation model are solved in sequence with each using the latest available flow or turbulence quantities.
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From page 627... ...
The quaternion formulation has the added advantage that the quaternion rate equations are linked to the angular rates by a set of linear differential equations. The linear velocities and displacements are obtained by directly integrating the accelerations after addition of the buoyancy and gravity terms in the inertial reference frame.
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From page 628... ...
~ (:: 0~) Figure 3 Comparison of lateral force coefficients computed using two turbulence models Validation of force and moment computations performed on the SUB OFF geometry as well as the thrust and torque computations on the P5 168 are particularly significant in the context of maneuvering simulations with rotating propulsors since they are necessary precursors to any maneuvering simulations.
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From page 629... ...
The results show that the q-co model tends to substantially overpredict resistance while the k-£ model is generally within 5%. The lateral force coefficient and the yawing moment coefficient show a drift in accuracy towards the higher yaw angles.
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From page 630... ...
Maneuvering experiments (Faller et al., 2001b) conducted at the Maneuvering and Seakeeping Basin at the Naval Surface Warfare Center, Carderock Division using the RCM include constant heading and depth runs, horizontal and vertical overshoots as well as controlled and fixed plane turns.
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From page 631... ...
The computed moment histories are compared with experiment in Figure 14 and show all the major trends in spite of the differences in control surface deflection histories near the maximum. The angular rates and orientations are compared in Figure 15 and in Figure 16 respectively and are in reasonable agreement.
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From page 632... ...
Thus there is a possibility that the moments of inertia have a high degree of uncertainty in comparison to the rest of the experimental data. The angular rates and accelerations in maneuvering simulations are strongly coupled with the linear accelerations and velocities through complex hydrodynamic interactions.
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From page 633... ...
[8] Faller, W.E., Hess, D.E., and Merrill, C.F., "ONR Bodyl Submarine Radio Controlled Model Experiments Part II: Baseline Maneuvering Data," NSWCCD-50-TR-2001/039, July 2001.
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From page 634... ...
[23] Sheng, C, Taylor, L K., and Whitfield, D.L., "An Efficient Multigrid Accleration for Solving the 3-D Incompressible Navier-Stokes Equations in Generalized Curvilinear Coordinates," AIM Paper No.
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From page 635... ...
~ Exp"Im~t . ~v ii .S~rnp~ne~ L ~ I ~ I I ~ ~ ~ ' ~f ~ ~: Figure 15 Comparison of angular rates for Run 41 .
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From page 636... ...
I 3 Tim A) Figure 21 Comparison of angular rates for Run 18 IN _ :~ ._ I-= ~ - : _ Ida .
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From page 637... ...
Ti Tame ~) Figure 27 Comparison of angular rates for Run 27 w ~ - a Compumion - -,.
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From page 638... ...
2: ~ > _ I ~~ ! ~~ ~ —~ ~ _ —Oa my Exp~ii~niS :s,:s;.:::~ F—— ~ , ~ s, ~ use Figure 33 Comparison of angular rates for Run 18 with propeller.
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From page 639... ...
am not that familiar with Fluent. However, I did not know that it had the capability to perform 6-DOF maneuvering calculations based on a high resolution solver with rotating propulsor and moving control surfaces on grids with y-plus of one at Reynolds numbers of 10*
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