Multiblock multigrid solution of three-dimensional incompressible turbulent flows about appended submarine configurations

Sheng, Chunhua; Taylor, Lafayette K.; Whitfield, David L.

doi:10.2514/6.1995-203

Cited by 22 publications

(19 citation statements)

References 11 publications

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“…Simulation of incompressible turbulent flow around naval vehicle models has made considerable progress in recent years [1,2,3,4,5]. While steady flow analysis could give us some insights into the flow physics and is commonly used in prediction of of hydrodynamic performance of underwater vehicles, unsteady flow simulation is of greater significance naturally because most flows are inherently time dependent.…”

Section: Introductionmentioning

confidence: 99%

Preconditioned multigrid methods for unsteady incompressible flows

Liu

Zheng

Liao

et al. 1997

35th Aerospace Sciences Meeting and Exhibit

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A highly efficient numerical approach based on multigrid and preconditioning methods is developed for modeling 3-D steady and time-dependent incompressible flows. The k-omega turbulence model is used to estimate the effects of turbulence. The model equations are solved together with the Navier-Stokes equations in a strongly coupled way, and acceleration techniques like multigrid methods are also used for the turbulence model equations. For unsteady problems, a dual-time-stepping procedure is adopted to satisfy the divergence-free constraint and to obtain time-accurate solutions. To improve the performance of this approach for a small physical time step, a modification to residual smoothing parameters is proposed. After the validation of the numerical algorithm and the turbulence model by calculating unsteady inviscid flow around an oscillating cylinder, unsteady laminar flow past a circular cylinder, and steady high-Reynolds-number turbulent flow over a 6:1 prolate spheroid, a three-dimensional time-dependent turbulent flow over a spheroid when it is undergoing a pitch-up maneuver is calculated and compared with experimental data. AbstractA highly efficient numerical approach based on multigrid and preconditioning methods is developed for modeling 3-D steady and time-dependent incompressible flows. The k-u turbulence model is used to estimate the effects of turbulence. The model equations are solved together with the N-S equations in a strongly-coupled way, and acceleration techniques like multigrid method are also used for the turbulence model equations. For unsteady problems, a dual-time stepping procedure is adopted to satisfy the divergence-free constraint and to obtain timeaccurate solution. To improve the performance of this approach for small physical time step, a modification to residual smoothing parameters is proposed.After the validation of the numerical algorithm and the turbulence model by calculating unsteady inviscid flow around an oscillating cylinder, unsteady laminar flow past a circular cylinder, and steady high-Reynolds number turbulent flow over a 6:1 prolate spheroid, a three dimensional timedependent turbulent flow over a spheroid when it is undergoing a pitch-up maneuver is calculated and compared with experimental data.

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Section: Introductionmentioning

confidence: 99%

Preconditioned multigrid methods for unsteady incompressible flows

Liu

Zheng

Liao

et al. 1997

35th Aerospace Sciences Meeting and Exhibit

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“…This solution scheme is referred to as a discretized Newton-relaxation [ 181, or the DNR scheme [17]. A multigrid scheme [19] is used to accelerate the numerical solutions, and this scheme has been extended to multiblock [20] and unsteady flows [21]. The present solution procedure is, therefore, a multigrid scheme for three-dimensional unsteady viscous flow on dynamic relative-motion multiblock grids.…”

Section: Implicit Unsteadv Incompressible Flow Solvermentioning

confidence: 99%

Parallel simulations for control-surface induced submarine maneuvers

Pankajakshan

Taylor

Jiang

et al. 2000

38th Aerospace Sciences Meeting and Exhibit

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This paper describes recent results on the development of an improved physics-based computational method for the determination of maneuvering characteristics of fully-configured self-propelled underwater vehicles, with particular emphasis on rotating propulsors, moving appendages and eventually full-scale Reynolds numbers. The scalable parallel solution methodology is briefly described, and results are given for a turning maneuver induced by a 10 degree rudder deflection. Aaditional results are given, including validation of force coefticients for a simple appended hull using both q-o and k--E turbulence models, a notional I I.4 bladed Sirenian propulsor with q+ turbulence model, and a solution with a body-force propulsor model. These simulations demonstrate new capabilities for both design and analysis of maneuvering propelled submarines, which will contribute both predictions andnew understanding that can help improve the design and operational safety of submarines.

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“…This solution scheme is referred to as a discretized Newton-relaxation [25], or the DNR scheme [24]. A multigrid scheme [26] is used to accelerate the numerical solutions, and this scheme has been extended to multiblock [4] and unsteady flows [5]. The present solution procedure is, therefore, a multigrid scheme for three-dimensional unsteady viscous flow on dynamic relative-motion multiblock grids.…”

Section: Implicit Unsteady Incompressible Flow Solvermentioning

confidence: 99%

“…The configurations include the bare hull, the bare hull with four stern appendages, and the bare hull with the sail. Numerous solutions at several angles of drift were computed in [4], [38] for each of these configurations, using a modified Baldwin-Lomax turbulence model. The computed force and moment coefficients are in extremely good agreement with the measured data (much better than anticipated at the An example of this simulation is given in Fig.…”

Section: Suboff Hullmentioning

confidence: 99%

Large-scale simulations for maneuvering submarines and propulsors

Taylor

Pankajakshan

Jiang

et al. 1998

29th AIAA, Plasmadynamics and Lasers Conference

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This paper describes an emerging computational capability for physics-based flow simulation and maneuvering predictions for appended submarine/propulsor geometries. The solution methodology for the unsteady Reynolds-averaged Navier-Stokes equations is summarized, including the transition of this capability from single-processor to scalable parallel computing. The current status of validation efforts for this methodology is discussed, including comparisons for appended-hull force and moment coefficients andpropulsor thrust and torque coefficients. Results are given from several simulations related to maneuvering of appended submarines with rotating propulsors. This capability will enable new complex simulations in computational naval hydrodynamics that can support the submarine design process as well as provide understanding leading to improved safety margins in submarines undergoing complicated maneuvers. To illustrate the impact of the scalable parallel code, a submarine maneuver requiring 3 million grid points and covering a distance of five hull lengths can be run in less than two days on 80 T3Eproc-essors, as compared with over four months on a single processor.

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Multiblock multigrid solution of three-dimensional incompressible turbulent flows about appended submarine configurations

Cited by 22 publications

References 11 publications

Preconditioned multigrid methods for unsteady incompressible flows

Preconditioned multigrid methods for unsteady incompressible flows

Parallel simulations for control-surface induced submarine maneuvers

Large-scale simulations for maneuvering submarines and propulsors

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