© MAHLE

Modeling of Wastegate actuator behaviour under

steady state and transient conditions

MAHLE Powertrain Ltd., Northampton, UK

Jens Neumeister

1

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Agenda

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 2

Model details

Steady state results

Transient load step at 2000rpm

Variations

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Model details: Overview

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 3

IC

ECU

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Model details: Boost solenoid

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 4

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Model details: Wastegate actuator

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 5

Upper Actuator Volume

Spring

Lower Actuator Volume

L1 L2

Diaphragm

L1 = L2

Actuator Rod

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Model details: Wastegate

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE

6

GT-Power geometry

Flapper Valve Real geometry

Upstream pressure

measurement

Downstream pressure

measurement

Measured wastegate cd

Difference on penny force

modeled via extra spring

based on CFD results

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Model details: GT-Power model

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 7

Boost Solenoid

Actuator Rod

Upper actuator can Volume

Piston Area

Penny Cd

Penny force correction

Spring Preload

Lower actuator can Volume

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Steady state results

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 8

Good BMEP correlation

MAP & Airflow well

correlated

Run-up line well

matched

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Steady state results

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 9

Actuator rod position

generally well matched

2000 & 2500rpm

show slight deviation

from measured

Turbine in pressure

slightly higher than

measured

Turbine in Temperature

slightly lower than

measured

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Steady state results

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 10

Combustion parameters

fit the measurement well

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Transient load step at 2000rpm

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 11

Engine speed

fluctuation during load

step <10%

Combustion

parameters based on

XY tables X=MAP

Y=50%BP respectively

10-90% Burn duration

Gross IMEP

correlation very good

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Transient load step at 2000rpm

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 12

Turbo speed and MAP

well matched

Lambda well matched

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Variations

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 13

2000rpm constant

90% of IMEP reached

0.23s later

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Variations

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 14

2000rpm constant

Duty Cycle set to

100%

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Variations

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 15

25% increased Spring

Stiffness

Steady State Results

At 6000rpm BMEP is

achieved at 0% duty

cycle

Target performance

becomes min boost

operating point at

6000rpm

No Boost control at

6000rpm

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Variations

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 16

25% increased Spring

Stiffness

Transient results

No significant gain in

transient response time

MAHLE Powertrain Ltd., DVP, Jens Neumeister, 2011-10-12

Conclusions

Modeling of Wastegate Actuator Behaviour Under Steady State and Transient Conditions

© MAHLE 17

Steady state correlates well

Transient correlation good

Test bed speed fluctuations have significant influence

on transient performance

Original Boost Control System well matched to engine

© MAHLE 18

Thank you