1d3d.ppt - TBM/Scher 1

nChristof Schernus, Thorsten Märtens, Werner Willems, FEV Motorentechnik GmbH & Co. KGMartin Hopp,Lehrstuhl für Verbrennungskraftmaschinen, RWTH AachenHeijo Oehlschlegel, FEV engine technology, Inc.

Presentation at the

GT-Suite User Conferences

nNovember 2, 1998Wings Hotel, Raunheim, Germany

nNovember 16, 1998Hilton Northfield, Troy, MI,U.S.A.

1D/3D Computational Analysis of a V6 S.I. Variable Intake Manifold

1d3d.ppt - TBM/Scher 2

1D/3D Computational Analysis of a V6 Variable Intake Manifold

n Why use 1D-3D coupled simulation?l High computational effort

L Long CPU time ⇒ reduced number of analyzed operating points / variations.

l Increased development efficiency ☺ Deep insight in flow phenomena and easier understanding

☺ Immediate feedback about design modifications

n Cost-benefit ratio has to be analyzed at the beginning of a Simulation Task to select appropriate toolsl Complexity of flow domain

l Applicability of pure 1D simulation

l Desired kind and detail of results

Introduction

1d3d.ppt - TBM/Scher 3

1D/3D Computational Analysis of a V6 Variable Intake Manifold

n Introduction

n 1D-3D Modeling Strategy

n Base Engine and Development Goals

n Intake Manifold Concept

n Calibration of GT-Power Model with Measured Data

n Packaged Intake Manifold

n 1D/3D-Simulation and Results

n Conclusions

Contents

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

1D-3D Modeling Strategy

Calibrated 1D Base Engine model

conceptstudy

CAD CFD

Hybrid model (1D+3D) of new design

Flow Characteristics of new design

Representative 1D model of the

3D domain

1D investigationmultiple speedmultiple load

Optimized VirtualIntake System

Experimental Data

Experimental Data

Experimental Data

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

n Base Enginel V6 S.I. passenger car engine

l Fixed intake manifold & valve timing

l 42 kW/L (56 bhp/L)

l 85 Nm/L (63 ft-pds/L)

n Development Goals:l 100 Nm/L (74 ft-pds/L) @ about 2500 rpm

l 55 kW/L (74 bhp/L) @ about 6000 rpm

l Variable intake manifold

l Package

l Minimum number of valves/variabilities

Base Engine and Development Goals

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

“Ideal Switch” System (Sim.)Component Intake System (Exp.)

Torque Runners

PowerRunners

≈≈+

Realistic VariableIntake System

Switched BranchedIntake System

Intake Manifold Concept

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

Packaged Intake Manifold

Plenum Chamber

Torque Runners

Shifting DrumPower Runners

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

Calibration of GT-Power Modelwith Measured Data

-120 0 120 240 360 480 600 7200.81.01.21.41.61.82.02.2

Exhaust Cyl. 6 Measured Calculated

Crank Angle [° ATDC Cyl. 1]

0

2

4

6

8

Cylinder 6

Pres

sure

[bar

]

0.6

0.8

1.0

1.2

1.4

1.6

Intake Runner Cyl. 6

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Validation of GT-Power Model by Measurement

1D/3D Computational Analysis of a V6 Variable Intake Manifold

800 1600 2400 3200 4000 4800 5600 64000.7

0.8

0.9

1.0

1.1

Engine Speed [rpm]

Volu

met

ric E

fficie

ncy

Measured PredictedComponent Intake System

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

1D/3D Simulation and Results

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

1D/3D Simulation and Results

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Velocity in Intake Manifold at 2800 rpm

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Velocity in Intake Manifold at 2800 rpm

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Pressure in Intake Manifold Cylinder 6 at 6000 rpm

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Velocity in Intake Manifold Cylinder 6 at 6000 rpm

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

1D/3D Simulation and Results

-120 0 120 240 360 480 600 720

1.0

1.5

2.0

2.5Exhaust Cyl. 6 1D+3D

pure 1D

Crank Angle [° ATDC Cyl. 1]

0

2

4

6

8

Cylinder 6

2800 rpm

Pres

sure

[bar

]

0.8

1.0

1.2

1.4

Intake Runner Cyl. 6

-120 0 120 240 360 480 600 720

1.0

1.5

2.0

2.5

3.0Exhaust Cyl. 6 1D + 3D

pure 1D

Crank Angle [° ATDC Cyl. 1]

0

2

4

6

8

Cylinder 6

6000 rpm

Pres

sure

[bar

]

0.8

1.0

1.2

1.4

Intake Runner Cyl. 6

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

Optimization Results

1000 2000 3000 4000 5000 6000 700050

60

70

80

90

100

Base Optimized

Torq

ue [N

m/l]

Engine Speed [rpm]

1000 2000 3000 4000 5000 6000 70000

10

20

30

40

50

60

Pow

er [k

W/l]

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1D/3D Computational Analysis of a V6 Variable Intake Manifold

n The 1D-3D link of STAR-CD and GT-Power is a useful tool to investigate details of dynamic flow in a subdomain of the intake or exhaust manifoldl The pressure oscillation behavior of all gas columns outside the

3D domain is considered by the 1D model

l Impact of design modifications can be evaluated immediately regarding engine fuel economy, and/or performance

l 3D CFD can be used to calibrate a pure 1D model, that is required to investigate the engine performance in a larger number of operating points.

n 1D-3D analysis results in deeper understanding of complex flow phenomena. Therefor, the application of this method can increase the efficiency of the development process, if cost-benefit ratio is considered carefully.

Summary and Conclusions