Using 1D simulations to optimize a supercharger

for a twin charged DI gasoline engine

2015-10-26 Ragnar Burenius, Volvo car Group

2015-10-26 USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP 1

VEA architecture

2015-10-26 2USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

NI4 2.0 GTDI DV6C 1.6Sigma 1.6 GTDI DW10C 2.0

SI6 I5DI5PV8

VEA

VEA – differentiated by boosting

2015-10-26 3USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

T5

T4

T6

D4

D3

D5

T3 D2

Introduction – T6 SC-turbo schematic

42015-10-26 USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

Introduction - Operating range of the sc

52015-10-26 USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

0

5000

10000

15000

20000

25000

0

100

200

300

400

500

1000 1500 2000 2500 3000 3500 4000 4500 5000 5500 6000

Supe

rch

arge

r Sp

eed

[rpm

]

Engi

ne

Brak

e To

rque

[N

m]

Engine Speed [RPM]

N/A

Turbo

Turbo+Supercharger

Supercharger Speed

INTRODUCTION – SC Performance MAP

2015-10-26 6USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

0 0.05 0.1 0.15 0.21

1.5

2

2.5

1k 2k 3k 4k 5k 6k 8k 10k 12k 14k 16k 18k 20k 22k 24k

Corrected massflow [kg/s]

PR

t-t

1

1,25

1,5

1,75

2

2,25

2,5

0 0,02 0,04 0,06 0,08 0,1 0,12 0,14 0,16 0,18 0,2

Pres

sure

rat

io [

-]

Mass flow [kg/s]

Steady state

Transient

What looks like a complex shape is really just a helix extrusion

Geometry Identification

2015-10-26 7USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

A scheme for geometry definition of the meshing event was developed in Matlab

Geometry analysis in 2D

2015-10-26 8USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

• Areas of 2D integrated to volumes of 3D.

• Leakage lengths integrated to leakage areas.

• Discretized in ten segments to account for meshing and axial resolution.

Helix extrusion

2015-10-26 9USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

Se

gm

en

t 1

0

Seg

me

nt

9

Seg

me

nt

8

Seg

me

nt

7

Seg

me

nt

6

Seg

me

nt

5

Seg

me

nt

4

Seg

me

nt

3

Seg

me

nt

2

Seg

me

nt

1

The system of volumes and orifices is implemented as a model in GT-Power

Implementation in 1D CFD

2015-10-26 10USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

InletRotor 1

Rotor 2Segm

ent

1

Segm

ent

2

Segm

ent

3

Segm

ent

4

Segm

ent

5

Segm

ent

6

Segm

ent

7

Segm

ent

8

Segm

ent

9

Segm

ent

10

Outlet

Results – performance prediction

2015-10-26 11USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

Measurement 1D CFD Simulation

0 0.05 0.1 0.15 0.21

1.5

2

2.5

0.5

0.5

0.5

4

0.5

4

0.5

8

0.5

8

0.6

2

0.6

2

0.6

6

0.6

6

0.7

1k 2k 3k 4k 5k 6k 8k 10k 12k 14k 16k 18k 20k 22k 24k

Corrected massflow [kg/s]

PR

t-t

0 0.05 0.1 0.15 0.21

1.5

2

2.5

0.5

0.5

0.5

4

0.5

4

0.5

8

0.5

8

0.6

2

0.6

2

0.6

6

0.6

6

0.7

0.7

4

0.7

4

1k 2k 3k 4k 5k 6k 8k 10k 12k 14k 16k 18k 20k 22k 24k

Corrected massflow [kg/s]

PR

t-t

Mass flow [kg/s] Mass flow [kg/s]Pr

essu

re R

atio

Pres

sure

Rat

io

0 0.05 0.1 0.15 0.21

1.5

2

2.5

0.5

0.5

0.5

4

0.5

4

0.5

8

0.5

8

0.6

2

0.6

2

0.6

6

0.6

6

0.7

1k 2k 3k 4k 5k 6k 8k 10k 12k 14k 16k 18k 20k 22k 24k

Corrected massflow [kg/s]

PR

t-t

0 0.05 0.1 0.15 0.21

1.5

2

2.5

0.5

0.5

0.5

4

0.5

4

0.5

8

0.5

8

0.6

2

0.6

2

0.6

6

0.66

0.7

0.7

0.7

4 0.7

8

0.5

8

1k 2k 3k 4k 5k 6k 8k 10k 12k 14k 16k 18k 20k 22k 24k

Corrected massflow [kg/s]

PR

t-t

0.5

0.54

0.58

0.62

0.66

0.7

0.74

0.78

In-cycle analysis – slow speed, PR=1.50

2015-10-26 12USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

In-cycle analysis – High speed, PR=1.05

2015-10-26 13USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

-0,01

0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,1

0,11

0

0,25

0,5

0,75

1

1,25

1,5

0 100 200 300 400

Mas

s Fl

ow

[kg

/s]

Pre

ssu

re

Rotational angle [degrees]

Pressure

Volume

Inlet flow

Outlet flow

Back flow

The addition of Outlet slots

2015-10-26 14USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

In-Cycle analysis – Effect of outlet slots

2015-10-26 15USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

-0,01

0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,1

0,11

0

0,25

0,5

0,75

1

1,25

1,5

0 100 200 300 400

Mas

s Fl

ow

[kg

/s]

Pre

ssu

re

Rotational angle [degrees]

Pressure

Volume

Inlet flow

Outlet flow

Back flow

-0,01

0

0,01

0,02

0,03

0,04

0,05

0,06

0,07

0,08

0,09

0,1

0,11

0

0,25

0,5

0,75

1

1,25

1,5

0 100 200 300 400

Mas

s Fl

ow

[kg

/s]

Pre

ssu

re

Rotational angle [degrees]

Pressure

Volume

Inlet flow

Outlet flow

Back flow

Without silencer slots With silencer slotsWithout outlet slots With outlet slots

Outlet slots – Performance impact

2015-10-26 16USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]P

Rt-

t

Simulation Test

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

-30

-20

-10

0

10

20

30

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

-30

-20

-10

0

10

20

30

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]P

Rt-

t

0 0.05 0.1 0.15 0.21

1.5

2

Corrected massflow [kg/s]

PR

t-t

-30

-20

-10

0

10

20

30%

• Methodology presented for simulating a helix roots type blower using 1D CFD.

• Calculated performance compared to test data.

• Improvements in geometry implemented based on analysis of gas exchange model.

• Improvements verified in testing, and later put in production.

Conclusions

2015-10-26 17USING 1D SIMULATIONS TO OPTIMIZE A SUPERCHARGER FOR A TWIN CHARGED DI GASOLINE ENGINE, RAGNAR BURENIUS, VOLVO CAR GROUP