comunicaÇÃo tÉcnica - ipt · 2018. 6. 22. · the use of cfd on the naval engineering research...

COMUNICAÇÃO TÉCNICA ______________________________________________________________________________________________________________________________________________________________________________________________________

Nº175344

The use of CFD on the Naval Engineering Research at IPT

João Lucas Dozzi Dantas

Palestra apresentada no SIMCETER USERS MEETING SOUTH AMERICA, 2018, São Paulo A série “Comunicação Técnica” compreende trabalhos elaborados por técnicos do IPT, apresentados em eventos, publicados em revistas especializadas ou quando seu conteúdo apresentar relevância pública. ___________________________________________________________________________________________________

Instituto de Pesquisas Tecnológicas do Estado de São Paulo S/A - IPT

Av. Prof. Almeida Prado, 532 | Cidade Universitária ou Caixa Postal 0141 | CEP 01064-970

São Paulo | SP | Brasil | CEP 05508-901 Tel 11 3767 4374/4000 | Fax 11 3767-4099

www.ipt.br

The use of CFD on the Naval

Engineering Research at IPT

IPT – Institute for Technological Research

João Lucas Dozzi Dantas – [email protected]

Agenda: About IPT – Institute for Technological Research

Vessel Resistance and Motion

Geometry simplification using porous approach

Propeller blockage and hydrophobic investigation

Laminar-turbulent transition model

2018-06-13 Page 3 Siemens PLM Software



IPT-NAVAL: Towing Tank

Large Section: 200 x 6.6 x 4.5 m

Narrow Section: 60 x 3.7 x 2.0 m

Maximum test speed: 3.5 m/s

Model length: up to 6.0 m


IPT-NAVAL: Cavitation Tunnel

Section test: 0.5 x 0.5 m²

Range of pressure: 0.2 ~ 1.6 atm

Propeller rotation: up to 3000 rpm

Advance velocity: up to 5.0 m/s

IPT’s Cavitation Tunnel, model Kempf & Remmers K18, was inaugurated in 1963 in a

partnership with Brazilian navy


IPT-NAVAL: Cavitation Tunnel: Instrumentation Capabilities

Force, torque and vibration

measurement

• Strain gauges and load cells

Strobe light

Velocity measurements

• Pitot

• Acoustic (ADV)

• Laser (PIV and LDV)

Measurement of dissolved oxygen

Underwater acoustic sensors

Vessel Resistance

and Motion Some results published in:

PELICIA, R.S.; DANTAS, J.L.D. Model Calm Water Resistance and Motion – Simulation, Experiments and Verification.The

30th American Towing Tank Conference. SNAME. 2017.


Vessel Resistance and Motion

Objectives

Calm water resistance test are common test in towing tanks, being

used to verify a hull performance or calibrate a numerical model.

• Verify the numerical model through mesh sensitiveness analysis

• Validate the numerical model by comparison of towing tank results


Case study

Two platform supply vessel model

Prototype planform:


Results: Resistance


Results: Wave incidence

Only M536 (Prototype I)

Draft of 6.6 m

Vp =1.048 m/s (15 knot)

Some results published in:

KATSUNO, E.T.; CASTRO, F.S.; DANTAS, J.L.D. Debris Containment Grid CFD validation with Towing Tank

Tests.The 30th American Towing Tank Conference. SNAME. 2017.

KATSUNO, E.T.; CASTRO, F.S.; DANTAS, J.L.D. Hydrodynamic Analysis of Debris Containment Grid in

Hydropower Plant Using Porous Media.24th International Congress of Mechanical Engineering. ABCM. 2017.

KATSUNO, E.T.; GOMES, G.G.; CASTRO, F.S.; DANTAS, J.L.D. Numerical Analysis of Debris Containment Grid

Fluid-Body Interaction.37th International Conference on Ocean, Offshore and Artic Engineering. ASME. 2018.

Simplification of a floating line

using porous approach


Objectives

Develop a simplified numerical model of a truncated version (with fewer modules)

of a debris containment grid line

• Dynamic Fluid Body Interaction - DFBI

• Several conditions: Advance velocity and side-slip angle

Hydrodynamic Investigation is conducted using CFD software


Methodology

Complete representation Simplified

representation using

porous media approach

Line with simplified

representation


Complete representation setup

Two DoF: sinkage of the module and rotation of the chassis

Two regions: domain region (include the grid) and chassis region

Boundary conditions of domain region

Boundary conditions of

chassis region

Log boom module:

Grid + chassis


Simplified representation setup

Dimensions are the same as complete representation.

Grid are simplified by a porous region

Fewer elements

Boundary Conditions of Domain (I), Grid (II), Chassis (III) and Frontal part of Chassis (IV) regions (figures

are not in the same scale)


Porous formulation

Comparative of complete and porous model in grid force magnitude (x and y directions)

(left); and in moment (right)


Log Boom line

Six simplified representation

• 13 regions with overset interfaces

Float-Grid

Grid-Grid

Edges


Next steps

Modeling porous region using Momentum source

Increase number os lof boom modules

Compare results with experimental values obtained in IPT’s Towing Tank


KATSUNO, E.T.; DANTAS, J.L.D. Investigação da metodologia para simulações de propulsores utilizando fluidodinâmica

computacional. 26º Congresso Nacional de Transporte Aquaviário, Construção Naval e Offshore. SOBENA. 2016.

KATSUNO, E.T.; DANTAS, J.L.D. Analysis of the Blockage Effect on a Cavitation Tunnel using CFD Tools. 36th

International Conference on Ocean, Offshore and Artic Engineering. ASME. 2017.

KATSUNO, E.T.; DANTAS, J.L.D.; SILVA, E.C.N. Analysis of Hydrophobic Painting in Model-Scale propeller. 37th

International Conference on Ocean, Offshore and Artic Engineering. ASME. 2018.

Propeller blockage and

hydrophobic investigation


CFD model study

Domain size study

V&V study

Mesh topology study

Turbulence model

Nu

mb

er

of e

lem

en

ts

Trimmed Polyhedral

Model KT KQ 𝜼

Experimental 0,330 0,0433 0,231

SA 0,317 0,0419 0,256

SST 0,316 0,0417 0,256

SST LowRe 0,316 0,0418 0,256

Realizable 𝒌 − 𝝐 0,317 0,0419 0,256


Open Water results

Periodic condition with cavitation model

Experimental comparatives


Cavitation and Blockage results

Results Results with blockage correction


Next steps

Analysis for lower cavitation number

Noted a high influence of blockage ratio in the cavitation area

Comparative between two blockage ratio for the same advance ratio of 0.249

Not contemplated in Glauert mode


Research at superhydrophobic painting

Perform a numerical analysis of superhydrophobic surface on propeller

Trade-off between gain in performance and suction pressure

Boundary condition not

implemented

Using Field Functions and

storing previous results in

Monitors


GOMES, G.G.; ESTEVES, F.R.; KATSUNO, E.T.; DANTAS, J.L.D. Simulations of Laminar–Turbulent Transition in foils using

CFD. 27º Congresso Internacional de Transporte Aquaviário, Construção Naval e Offshore. SOBENA. 2018.

Laminar-Turbulent transition

model


Laminar to turbulent transition simulations using Gamma-

ReTheta turbulence model

Transition for the S9000 airfoil, α = 5.21 degrees.

Intermittency field (upper figure), alongside the wall shear stress for the upper

side of the airfoil, transition occurs between Rex = 9*10⁴ and 1.1*10⁵


Bubble comparative

Comparison between the

separation bubble in the

upper side of the airfoil

obtained with the SST low-

Reynolds Turbulence model

(top) and with γ-Reθ (bottom)


Turbulence Intensity

Use of ambient turbulent source to counteract turbulence decay


Comparison with other turbulence models for simulations with low-Reynolds

number over airfoils

NACA43012A airfoil using different turbulence models with experimental data

Re = 6e4

Comparison with experimental values


Conclusions

CFD has demonstrated great potential in assisting NAVAL-IPT experiments,

allowing new types of analysis and results to be incorporated into the laboratory

portfolio.

NAVAL-IPT will continue to improve its researchers to use this tool to offer more

specialized services to their clients

João Lucas Dozzi Dantas

Head of Laboratory

Naval Architecture and Ocean Engineering Laboratory

Center for Mechanical, Electrical and Naval Technologies

[email protected]

comunicaÇÃo tÉcnica - ipt · 2018. 6. 22. · the use of cfd on the naval engineering research...

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