Advanced Physics-based CAE solutions for Optimizing Fuels ...€¦ · K2 – Fast response...

confidential. © cmcl innovations, 2013

Advanced Physics-based CAE solutions for Optimizing Fuels, Combustion Modes and Emissions in modern ICEs

Dr. Amit Bhave cmcl innovations

UKTI’s Clean Technology Seminar 12 January 2013 Pune, India


contents

• CAE at cmcl innovations

• kinetics & srm engine suite : predictive simulation

• practical application#1: Diesel engine optimisation

• practical application#2: Advanced SI engine

• practical application#3: fuel-engine correlations

• Q&A


CAE at cmcl innovations


target markets

- automotive, heavy duty and non-road powertrain

- fuels, feedstocks and clean energy

- chemical process industry

cmcl innovations

software | consulting | training


CAE products for virtual engineering

srm engine suite – multi-award winning advanced IC engine fuels, combustion and emissions simulator

mod suite – model development suite, data

standardisation, uncertainty propagation,

parameter estimation, optimisation

kinetics – chemical kinetics mechanism builder, fuel models and emissions pathways analysis, reactor models for chemical industry,

CFD plugins – multi dimensional reactive flow dynamics


CAE partner in collaborative R&D projects

LiLa – Library of Labs for remote experiments and virtual

laboratory in science and engineering

Role: Industrial partner

Technical: virtual laboratory for IC engine applications

Model Surrogates – High dimensional model reduction (HDMR)

Role: Project sponsor/coordinator

Technical: Surrogate model development, benchmarking and applications

TESBiC – Techno-Economic Study of Biomass to power with CO2 capture

Role: Project Lead/Coordinator

Technical: Model development, parameter estimation, optimisation

K2 – Fast response algorithms and real-world data coupling for non-road engines/machines

Role: Technical industrial partner

Technical: Surrogate model development, data mining, virtual engineering

C-FAST project: Carbon-negative fuels

Role: Project coordinator

Technical: Techno-economic engineering analysis and design


our customers’ main challenges

Combustion

knock, misfire, ignition, low temperature combustion

Modern techniques

boosting exhaust gas residuals

multiple direct injection

Emissions

CO, uHCs, NOx, soot particles

(including number density

and composition)

Fuels

alternative fuels fuel development fuel reformation

kinetics & srm engine suite “Efficient Physics-based Predictive Insight into Fuels, Combustion and Emissions in modern ICE context”


CAE application – an example

TRL: Technology Readiness Level

SRM: Stochastic Reactor Model


kinetics & srm engine suite


3D CFD software tools

In-cylinder optimisation

• CPU time days/cycle

• predictive combustion

• predictive emissions in

some cases

• limited by CPU time

modelling fuels, combustion and emissions

Stochastic Reactor Models

• CPU time seconds to minutes • predictive combustion and emissions • turbulence, heat transfer, MDI, EGR, fuel volatility

1D multi-cycle software tools

breathing, valve train and

engine optimisation

• CPU time seconds/cycle

• poor predictive combustion

• poor predictive emissions

• integration into 1D cycle tools • more efficient solution for combustion optimisation

• properly account for chemical kinetics i.e. ignition, extinction, misfire, flame propagation and emissions


Combustion: Compression Ignition Direct Injection Port & Direct Injection Spark Ignition Low temperature combustion (HCCI, PCCI etc.)

Fuels: Gasoline, Diesel, bio-fuels, CNG etc., fuel blends Emissions: All regulated (PM, NOx, UHCs, CO) and unregulated Easy-to-use: Graphical interface Batch running, parallelised

Short CPU times Coupling with 3rd party tools

fuels, combustion and emissions

11

kinetics & srm engine suite


different modes of combustion

Mode DISI advanced CIDI

SOI [aTDC] -100 -100 -2

EOI [aTDC] -90 -90 25

C.R. 11 15.0 15.0

PIVC [bar] 0.75 1.2 1.2

TIVC [K] 450 450 550

Fuel gasoline diesel diesel

Fuel [mg] 10.0 10.0 10.0

1500 RPM ~2.62BMEP 30% EGR

PCCI/LTC/HCCI CIDI DISI


options for running the srm engine suite

1. either in a stand-alone mode that models engine breathing and closed volume portion of the engine cycle

OR

2. coupled with 1D engine cycle toolkits to account for engine environment: piping, turbochargers, EGR coolers etc.

OR

3. tabulated srm suite for real-time simulation with option 2.


practical application#1: diesel engine optimisation


CAT Diesel engine

1500 rpm

Same fuel concentration – 63mg

Single Injection

0 0.1 0.2 0.3 0.4 0.5 0.6 -10

-50

510

0

50

100

150

Ignition Timing [CAD aTDC]

EGR Mass [Fraction]

Manifold

Pre

ssure

[kP

a]

Injection Timing [CAD aTDC]

practical application#1: diesel engine optimisation

15

SAE 2011-01-1388

confidential. © cmcl innovations, 2013 16

in-cylinder pressure profile - I


in-cylinder pressure profile - II


in-cylinder pressure profile - III


model-experiment

inconsistency

19

in-cylinder pressure profile - IV


NOx emissions


CO emissions


• srm suite – a physics based simulation tool for optimisation

• at 0.3 EGR mass fraction

• parametric sweep of – Manifold pressure

– Injection timing

• Isolate their impact on heat release and emissions

0 0.1 0.2 0.3 0.4 0.5 0.6 -10

-50

510

0

50

100

150


EGR Mass [Fraction]

Manifold

Pre

ssure

[kP

a]

Injection Timing [CAD

22

optimisation domain


-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110


Manifold

Pre

ssure

[kP

a]

45s per computation

Matrix of 88 – total computational time 66 minutes

23

interpolation / extrapolation


Peak pressure [bar] CA50 [CAD]

2

22 44

4

66

6

88

8

10

10

12

12

15

15

18

18

20

20

22

22

25

25


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110

70

70

7070

80

80

8080

90

90

90

90

100

100

100

100

120

120

120

140

140

160

160

180


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110

2020

30

30

30

40

4040

50

50

50

60

60

70

70

80

80

90

90

100

100

110

110

120

120

130

140

140


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110

dp/dCAD [bar/ms]

0.40.4

0.4

0.425

0.425

0.45

0.450.45

0.475

0.4750.475

0.5

0.50.5

0.5250.525

0.525

0.55

0.550.55

0.575

0.5750.575

0.60.6

0.6


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110

Total equivalence ratio [-]

Injection Timing [CAD aTDC] Injection Timing [CAD aTDC]


24

impact due to constraints


NOx [ppm] CO [ppm]

10

1010

25

2525

50

50

75

75

100

100

125

125

150

150

175

175

200

200

225

250

300

350


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110

100100

100

300

300

300300 600600

600

600

900900

900

900

20002000

2000

4000

4000

8000

12000

2000


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110

5

5

5

55 10

10

10

20

20

20

50

50

100

100

10

200

400

200

5


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110

UHCs [ppm]


Injection Timing [CAD aTDC] 25

Interpolation / extrapolation - emissions


10

1010

25

2525

50

50

75

75

100

100

125

125

150

150

175

175

200

200

225

250

300

350


Manifold

Pre

ssure

[kP

a]

-10 -8 -6 -4 -2 0 2 4 6 8 1020

30

40

50

60

70

80

90

100

110


NOx [ppm]

26

where to operate?


impact of EGR

00.1

0.20.3

0.40.5 -10

-5

0

5

10

0

25

50

75

100


EGR [fr.]

Manifold

Pre

ssure

[kP

a]

EGR Injection timing [CAD aTDC]

Man

ifo

ld p

ress

ure

[kP

a]

• From 4 experimental data points – an educated estimate of the optimal operating point

• Using conventional CFD- months of CPU time


practical application#2: DISI engines


DISI engine mode

simulating cyclic variations turbulent flame speed varied significant impact on emissions


SI combustion: “downspeeding”

intake pressure 2.2 bar, 1000rpm retarded ignition some cycles pre-ignited

oil-ignition was simulated


GDI SI: soot size distribution

• Stratified operation improves fuel economy but increases in-cylinder fuel-rich pockets

• Fuel impingement and lack of mixing result in soot/particulate matter emissions

• Particle number emissions from

gasoline engines – pending regulations


12.6 CAD ATDC 32.6 CAD ATDC 2.6 CAD ATDC

GDI SI: soot aggregates


experiment simulation

SI-HCCI transients: mode switching


practical application#3: fuel-engine correlations


practical fuel modelling

Conventional fuels

(a) Research Octane Number (RON)

(b) Octane "Sensitivity" (RON – MON)

Tri-component surrogate fuels increase the robustness of practical fuel modelling as fuel sensitivity can also be simulated

fuel blends practical gasoline ethanol/gasoline blending biofuels & future fuels


gasoline – fuel for advanced diesel engine ?

A 0.537 litre single cylinder diesel engine with a compression ratio of 15.8:1 operated using an 84 RON gasoline fuel. Bosch injectors were adopted with seven holes of 0.13mm diameter. Single injection SOI =-11.2 CAD aTDC, Triple injections a) 25% SOI @ -180 CAD aTDC, b) 15% @ - 76 CAD aTDC and main @ -7 CAD aTDC.


multiple injection strategies

dp/dt [bar/CAD] burn duration [CAD]

NOx emissions [-] CO emissions [-] uHCs emissions [-]

~12 bar IMEP


Experiments carried out by Shell

engine specification

38

Compression ratio (CR) 15.9:1 Displacement 0.537 l

Bore 88 mm Stroke 88.3 mm

Connection rod length 149 mm Inlet valve open (IVO) 362 CAD Inlet valve close (IVC) 595 CAD

Exhaust valve open (EVO) 143 CAD Exhaust valve close (EVC) 385 CAD

Speed 1200 RPM Manifold pressure 1.0 bar (a)

Manifold temperature 65 deg C Exhaust pressure 1.0 bar (a)

IMEP 4.0 bar Injection pressure 650 bar Equivalence ratio 0.370 Air mass flow rate 6.03 g/s

84 PRF n-heptane RON 84 0 MON 84 0

vol. % of iso-octane 84 0 vol. % of n-heptane 16 100

Density (g/cc) 0.682 0.632 C 7.83 7.0 H 17.67 16.0

LHV (MJ/kg) 44.4 44.6

Table 1 – Engine specification.

Table 2 – Engine operating point.

Table 3 – Fuel properties.


example impact of fuel

Fuel Gasoline Diesel

SOI [aTDC] -8 -8

EOI [aTDC] -4 -4

1200 RPM

4bar iMEP

5% EGR

84PRF gasoline fuel – low PM

diesel fuel (n-heptane)


summary

• kineticsTM & srm engine suite is a practical tool for assessing combustion efficiency, fuel consumption, and emissions in the development of improved ICEs fuelled with conventional and alternative fuels

• for multiple engine cycles-based analysis, 1D engine cycle tools are practical and can further add value if inhomogeneities and chemical kinetics is accounted

• it is always beneficial to minimise the number of model parameters thus, in turn, reducing the effort associated with parameter estimation (also termed as model calibration or model validation)

• optimisation and extrapolation based on physics-based models rather than purely statistical ones offers model robustness and hence more predictive capability.


kinetics & srm engine suite applications

• emissions in 1D context • any fuel can be analysed • explore operating strategies • minimise emissions • meet engineering constraints • inform experiments • understand the key processes • steady state & transient

Advanced Physics-based CAE solutions for Optimizing Fuels ...€¦ · K2 – Fast response...

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