www.cd-adapco.com

STAR-CCM+OLGA Co-simulation of

Oil & Gas Pipeline Flows

by Abdel Fiala

Application Proving Group

Contents

• Problem description

• Geometry & mesh details

• Boundary & initial conditions

• Material properties

• Physics & solver settings

• Run controls

• Performance data

• Time history plots

• 3D liquid holdup visualisation

• Animations

• Concluding remarks

• Outstanding issues & enhancements

Application Proving Group

2

Problem Description

• Simulation of three-phase Oil-Gas-Water flows in long multiple pipelines, linked via connective devices where 3D effects are predominant

– OLGA: Simulation of flow in the long pipelines

– STAR-CCM+: Simulation of flow in the connective devices

» Examples of connective devices:

- Junctions

- Valves

- Obstacles/restrictions

- Elbows

- Jumpers

• The two simulations are coupled and run simultaneously as a “STAR-CCM+OLGA co-simulation”

Application Proving Group

3

Co-simulation

• Information transfer between the two codes via one-way coupling (OLGA to STAR-CCM+) and two-way coupling

• In this project, one-point, two-point, and three-point coupling (n-point possible)

– One-point: » OLGA Outlet ↔ STAR-CCM+ Inlet

– Two-point:» 2 x [OLGA Outlet ↔ STAR-CCM+ Inlet]

» [OLGA Outlet ↔ STAR-CCM+ Inlet]

+ [STAR-CCM+ Pressure ↔ OLGA Source]

– Three-point:» 2 x [OLGA Outlet ↔ STAR-CCM+ Inlet]

+ [STAR-CCM+ Pressure ↔ OLGA Source]

Application Proving Group

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Co-simulation … Application Proving Group

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Example Set-up

I1: Interface1; 1st coupling ptOLGA Outlet – STAR-CCM+ Inlet

I2: Interface2; 2nd coupling ptOLGA Outlet – STAR-CCM+ Inlet

I3: Interface3; 3rd coupling ptSTAR-CCM+ Pressure – OLGA Source

I1

I2

I3

OLGA

Source 1

OLGA

Source 3

OLGA

Source 2

OLGA

Outlet 1

OLGA

Outlet 3

OLGA

Outlet 2

STAR-CCM+

Pressure

STAR-CCM+

Inlet 2

STAR-CCM+

Inlet 1

Geometry (pipelines)

OLGAApplication Proving Group

6

Pipelines diameter : 10in

Geometry (connective devices)

STAR-CCM+Application Proving Group

Case Name Case Description

Elbow 90º elbow

RestrictorSingle Narrow single-restriction cylinder

RestrictorDouble Mild double-restriction cylinder

Tjunction00 Flow-merging planar T-junction

Tjunction60 Flow-merging 60º T-junction

Tjunction90 Flow-merging 90º T-junction

JumperBend Jumper with part-circular bends

JumperRec Jumper with part-circular/part-rectangular bends

Split Flow-split junction

Pig Pig launcher/receiver

7

SET-A : One and two-point coupling

OLGA upstream pipelines Outlet(s) ↔ STAR-CCM+ Inlet(s)

Geometry (connective devices)

STAR-CCM+ ...Application Proving Group

Case Name Case Description

RestrictorSingle (2) Narrow single-restriction cylinder

Tjunction90 (2) Flow-merging 90º T-junction

8

SET-B : Two and three-point coupling

OLGA upstream pipelines Outlet(s) ↔ STAR-CCM+ Inlet(s)

+

STAR-CCM+ Pressure ↔ OLGA downstream pipeline Source

Mesh Details

• Pipe diameter: D = 0.254m = 10in

• Models:

– Surface remesher

» Curvature = 72pt

» Size = 0.06D

– Poly mesher

– Prism layer mesher

» Layers = 3

» Total thickness = 0.06D

» Stretching factor = 1.5

– Generalized cylinder mesher

» Streamwise cell spacing ≈ 0.15D to 0.3D

Application Proving Group

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90º Elbow Application Proving Group

10

Flow-Restriction Cylinders Application Proving Group

Narrow single-restriction

Mild double-restriction

11

Flow-Merging T-junctions Application Proving Group

Planar

60º

90º

12

Jumpers Application Proving Group

13

JumperBend

JumperRec

Flow-Split Junction Application Proving Group

14

Pig Launcher/Receiver Application Proving Group

15

Boundary Conditions

(OLGA)

• Upstream pipeline

– Inlet: Source

» Mass flow rate = 60 kg/s

» Mass fractions:

- yo = 0.81

- yg = 0.09

- yw = 0.1

» p = 70 bar

» T = 20 C

– Outlet: Pressure

» p = 80 bar

» T = 20 C

Application Proving Group

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– Wall: Heat Transfer» 19 sections

» Ambient temperature, T∞ :- 4 x 40, 35, 30, 25,

- 5 x 20,

- 25, 30, 35, 4 x 40

» h∞ = 19 x 200 W/m2C

• Downstream pipeline– Wall: Heat Transfer

» 17 sections

» T∞ = 17 x 20 C

» h∞ = 17 x 500 W/m2C

– Outlet: Pressure» p = 60 bar

» T = 20 C

Boundary & Initial Conditions

(STAR-CCM+)

• Boundary Conditions

– Inlets: Velocity

» Coupled

» Turbulence

– Outlets: Pressure

» p = 80 bar

» T = 20 C

» Turbulence

– Wall: Convection

» T∞ = 40 C

» h∞ = 200 W/m2K

Application Proving Group

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• Initial Conditions

– p = 80 bar

– T = 20 C

– U = V = W = 0.0 m/s

– αo = αw = 0 , αg = 1

– Turbulence

Material Properties

• OLGA fluid properties PVT table file (*.tab)

– Properties = f (p,T)

» Density ρ and its derivatives ∂ρ/∂p and ∂ρ/∂T

» Viscosity, μ; Specific heat, cp; conductivity, k; Surface tension, σ

– Complex Three-phase mixture;» Mole number, N, and molecular weight, M, given

- Oil : 19 components

- Gas : 3 components

- Water

• STAR-CCM+

– ρ, ∂ρ/∂p (and ∂ρ/∂T in v5.06): interpolated from OLGA table

– μ, cp, k, M: constant values (averaged OLGA table data) set by user

– No surface tension for three-phase+ mixtures

Application Proving Group

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Physics & Solver Settings

• Multiphase treatment– Phases: [1, 2, 3] = [Oil, Gas, Water]

• OLGA EoS

• Gravity

• Spatial discretisation: 2nd order convection– Volume of Fraction (VOF)

» Sharpening factor = 0.5

– Segregated flow

– Segregated multi-phase temperature

– All y+ k-ω SST turbulence

• Temporal discretisation: 1st order– Implicit unsteady

– Maximum inner iterations = 6

Application Proving Group

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Run Controls

• Run for a few flow passes

– Total physical time = 4 to 15.9 sec

– Time step size = 0.001 sec

– Run in parallel on desktops and clusters

– More details on next slide (S21)

• Two-way coupling

– Couple From Step = 10

– i.e. for first 10 time steps, only OLGA sends information to

STAR-CCM+

stability of STAR-CCM+ solution

Application Proving Group

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SET-A: Performance Data Application Proving Group

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GEOMETRY Ncell Ncell / Np tPhy (sec) Δt (sec) Imax CPU (sec) CPU (h) Np System Lpipe (m) R1 R2 R3 R4

Elbow 28980 4830 4 0.001 6 10567 2.9 6 desktop 3.01 2642 912 5469 5264

RestrictorSingle 26520 3789 5 0.001 6 10776 3.0 7 cluster 2.54 2155 813 5689 5940

RestrictorDouble 29880 4269 5 0.001 6 10789 3.0 7 cluster 2.54 2158 722 5055 5947

Tjunction00 63188 10531 4 0.001 6 32496 9.0 6 desktop 5.21 8124 1286 7714 9361

Tjunction60 63034 31517 4 0.001 6 68800 19.1 2 desktop 5.22 17200 2729 5457 6584

Tjunction90 75739 12623 6 0.001 6 45877 12.7 6 desktop 6.31 7646 1010 6057 7267

JumperBend 171898 42975 7.4 0.001 6 179472 49.9 4 desktop 14.75 24253 1411 5644 6578

JumperRec 135893 22649 8 0.001 6 89064 24.7 6 desktop 12.39 11133 819 4915 5391

Split 170437 24348 8 0.001 6 73672 20.5 7 cluster 15.46 9209 540 3782 4170

Pig 175033 11669 15.9 0.001 6 139568 38.8 15 cluster 14.52 8778 501 7522 9068

R1 = CPU / tPhy MAX 24253 2729 7714 9361

R2 = CPU / tPhy

/ 10kCells MIN 2155 501 3782 4170

R3 = CPU / tPhy

/ 10kCells / OneProcessor AVG 9330 1074 5731 6557

R4 = CPU / tPhy

/ Meter / OneProcessor

SET-A: Time Histories

“Elbow”Application Proving Group

22

SET-A: Time Histories

“Tjunction90”Application Proving Group

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SET-A: Time Histories

“Split”Application Proving Group

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SET-A: Time Histories

“Pig”Application Proving Group

25

Time Histories: “Tjunction90”

STAR-CCM+ vs OLGAApplication Proving Group

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Coupling interface mass flow rate Coupling interface temperature

Time Histories: “Split”

STAR-CCM+ vs OLGAApplication Proving Group

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Coupling interface mass flow rate Coupling interface temperature

SET-A: 3D Liquid Holdup

“Elbow”Application Proving Group

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SET-A: 3D Liquid Holdup

“RestrictorSingle”Application Proving Group

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SET-A: 3D Liquid Holdup

“RestrictorDouble”Application Proving Group

30

SET-A: 3D Liquid Holdup

“Tjunction00”Application Proving Group

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SET-A: 3D Liquid Holdup

“Tjunction60”Application Proving Group

32

SET-A: 3D Liquid Holdup

“Tjunction90”Application Proving Group

33

SET-A: 3D Liquid Holdup

“JumperBend”Application Proving Group

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SET-A: 3D Liquid Holdup

“JumperRec”Application Proving Group

35

SET-A: 3D Liquid Holdup

“Split”Application Proving Group

36

SET-A: 3D Liquid Holdup

“Pig”Application Proving Group

37

SET-A: Animations Application Proving Group

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SET-A: Animations … Application Proving Group

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SET-B: Animations Application Proving Group

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Concluding Remarks

• Co-simulations of flow in multiple-pipeline systems with

connective devices were conducted using CD-adapco’s

STAR-CCM+ and SPT’s OLGA software

• Successful coupling between the two codes

• Flowfield in connective devices demonstrated:

– High three-dimensionality

– Flow regime alteration

» From stratified to churn, annular, and swirling

– The possibility of designing connective devices that produce

certain flow regimes/patterns as required

– The objectives behind coupling

Application Proving Group

41