Simulation of a Hydraulic Cam Phaser Motion with 6-DOF morphing and Overset mesh Thomas Fischer, Daimler AG Berlin Plant Kai Fellmann, Daimler AG Berlin Plant Vienna, 03/17/2014

Organization

1. Introduction − Design and Function of a Hydraulic Cam Phaser

− Tasks for the CFD Simulation with STAR-CCM+

2. CFD Simulation of the Cam Phaser − Design of the Simulation Model in STAR-CCM+

− Java Macro for Controlling the Simulation

3. Selected Results

4. Summary

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1. Introduction

Design and Function of a Hydraulic Cam Phaser Tasks for the CFD Simulation with STAR-CCM+

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Design and Function of a Hydraulic Cam Phaser

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1. Introduction

Outlet

Inlet

Cylinder head of a 4-cylinder gasoline engine with two cam phasers Cam phaser inlet

Design and Function of the Hydraulic Cam Phaser

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1. Introduction

Position valve with

piston

Camshaft

Sprocket

Electro-magnetic

valve actuator

Vane piston

Lock pin

Design and Function of the Hydraulic Cam Phaser

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1. Introduction

Position valve with

piston

Camshaft

Sprocket

Electro-magnetic

valve actuator

Vane piston

Lock pin

Tasks for the CFD Simulation with -CCM+

• How does the design of the oil chambers affect the "adjustment speed" target variable?

• How can the performance of the system be improved by optimizing the oil chambers and the valve at the digital assembly stage?

• Calibration of the 1D system simulation at the digital assembly stage

Less time and effort involved in testing

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1. Introduction

Time [s]

-50

-40

-30

-20

-10

0

10

Pha

seA

ngle

Inle

t R [[

deg]

]

0

25

50

75

100

TV N

W2

[%]

Measurement

Time01 [sec]

-50

-40

-30

-20

-10

0

10

Cal

cula

ted

Pha

seA

ngle

Inle

t R [d

eg]

-1.5

-1

-0.5

0

0.5

1

1.5

2

Spo

ol L

ift:Z

V_P

-Adv

Ch-

1 [m

m]

1D Simulation

PhasingInlet right T=90 degCn=1000 rpmp=1,8 bar(rel.)

500 750 1000 1250 1500 1750 2000 2250 2500 2750 3000Crank speed [rpm]

-10

0

10

20

30

40

50

60

70

80

90

100

110

120

Tem

pera

ture

[°C

]

Phasing speed [deg/s]

2. CFD Simulation of the Cam Phaser Design of the Simulation Model in STAR-CCM+ Java Macro for Controlling the Simulation

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Design of the Simulation Model in STAR-CCM+

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2. CFD Simulation of the Cam Phaser

Cylinder Head

Cam Phaser

Design of the Simulation Model in STAR-CCM+

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2. CFD Simulation of the Cam Phaser

Cam Shaft Bearing with Groove

Cam Phaser Chamber

Design of the Simulation Model in STAR-CCM+

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2. CFD Simulation of the Cam Phaser

Stagnation Inlet

Pressure Outlet

Design of the Simulation Model in STAR-CCM+

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2. CFD Simulation of the Cam Phaser

Fixed Regions

Motion Specification: Stationary

Region CamShaft

Motion Specification: Rotation

Design of the Simulation Model in STAR-CCM+

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2. CFD Simulation of the Cam Phaser

Region Chamber

Motion Specification: DFBI Morphing

Design of the Simulation Model in STAR-CCM+

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2. CFD Simulation of the Cam Phaser

Region LockPin

Motion Specification: DFBI Morphing

Interface: Overset Mesh

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Lock Pin

Background / Overset Mesh

Design of the Simulation Model in STAR-CCM+ Volume Mesh

2. CFD Simulation of the Cam Phaser

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Design of the Simulation Model in Star-CCM+ Volume Mesh

2. CFD Simulation of the Cam Phaser

Java Macro for Controlling the Simulation

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2. CFD Simulation of the Cam Phaser

Start

Current Time Step=

… ?

Move Piston

Mesh Pipeline

Current Time Step=

… ?

Move Piston

Mesh Pipeline

Current MinCell Quality

<= … ?

Mesh Pipeline

CurrAngle < MaxAngle?

Run

CurrentAngleReverse=CurrAngle

TimeStepForward =CurrentTimeStep

true

false

true true

true

false false

false

End of Forward

Movement

Start Reverse Movement

3. Selected Results

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Flow Speed Value at Selected Intersecting Planes

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3. Selected Results

Flow Speed Value at Selected Intersecting Planes

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3. Selected Results

Pressure Distribution During Adjustment

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3. Selected Results

Pressure Distribution During Adjustment

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3. Selected Results

Comparative Presentation of the Phasing Angle over Time for Different Design Variants

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3. Selected Results

4. Summary

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Summary

• The hydraulic cam phaser can be simulated by means of different movements in STAR-CCM+.

• A Java macro is used for controlling the required valve movements and the remeshing of the morphed region.

• The modular simulation model can be easily adapted to new designs.

• The impact of the design of the oil chambers on the "adjustment speed" target variable can be calculated and optimized at the digital assembly stage.

• Calibrating the 1D system simulation at the digital assembly stage helps to generate reliable performance maps.

The time and effort involved in testing is significantly reduced.

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4. Summary

Thank you for your attention! Special thanks to the

Nürnberg Support-Team!

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