[PPT] - Comple plex x chemis mistr try y with h DARS Ka Karin Frjd PowerPoint Presentation

SLIDE 1

Comple plex x chemis mistr try y with h DARS

Ka Karin Fröjd

SLIDE 2

Enabli bling ng det etai ailed led chem emistr try in your r CAE simul ulations ations

Take

e the righ ght desi sign gn choi

ices

ces, incl cluding ng chem emical al effec ects ts

Fast

ster er and cheaper eaper desi sign cycles cles

Evaluat

valuation

n of enti

tirel rely new desi signs gns

Why DARS? S?

SLIDE 3

To capture ure chemica emical l effects ects Em Emissi sions

ns

Ignit ition ion delay y times es Lamin minar r flame me speeds eds New w fue uels s & f fue uel l blends ends

Why comple lex chemis istr try? y?

Igniti tion dela lay y times s for diff ffere rent natu tural ral gas s quali liti ties Soot t surface face growth wth as funct ctio ion of mixtu ture re fract ction ion for r n- heptan tane comb mbust stio ion at variou ious s strain in rate tes

SLIDE 4

What is DARS? S?

4 Standalone ndalone softw tware are for r 0D and 1D analys yses es of chemical emical reacti ctions

ns

Chem emist stry y analys yses Mecha hanism nism reduct ction ion Idealized ealized react ctor

rs

– Ignition delay time – Emission production – Flame speed calculations

Libr brar ary y generati neration

n

1D & 0D PDF mode dels s for in-cyl cylinde inder r combus mbusti tion

n and

after ertr treatm tmen ent DARS ARS v2.10 0 releas ased! ed!

Focus

s on libr brar ary gene neration tion fo for r STAR AR-CC CCM+ M+ an and STAR-CD CD

SLIDE 5

DARS

5

SLIDE 6

Impor mport t any mechani chanism sm in DAR ARS S Basic An Analys yse e the e chemist emistry y in react ctor

rs

s and flames mes Un Under derst stand and reacti ction

n pathways

ys throu

ugh

gh species cies flow w analys ysis

Chemistr mistry analysi lysis

Igniti tion dela lay y times s as functi ction of tempe perat ature for n-he hepta tane n-hepta tane deco composit sitio ion CO producti ction in fuel rich ch combusti stion of n-hepta tane

SLIDE 7

n-he hepta tane ne comb mbusti tion,

n, p=20

0 bar

Ignit ition n delay y times mes

SLIDE 8

Lamin minar ar flame me speeds eds

8

Laminar flame me speed as function tion of equival alenc nce rati tio and u unburned temperatu ture

Lamina nar flame e speeds eds with detail ailed ed chem emistr istry (291 species, ecies, 3081 1 reactio tions) ns) for a mixtur ure e of 95% iso-oc

ctane,

ane, 5% n-hept eptane ane in air

Laminar flame me speed as function tion of unburned temperatu ture and p pressure

The laminar flame speeds generated by DARS can be used by the PCFM model in STAR-CCM+

Minor r speci cies

C2H2 CH2O HO2

Fuel l & main n species cies

CO2 CH4 CO OH

SLIDE 9

Soo

ot

t for n-hep hepta tane ne combust mbustion, ion, p=50 bar

Emission ission mapping ing

SLIDE 10

NO for n-he hepta tane ne comb mbust stion, ion, p=50 bar

Emission ission mapping ing

SLIDE 11

CO for n-hept heptane ane combust mbustion ion, , p=50 0 bar

Emission ission mapping ing

SLIDE 12

To avoi

id

d large e CPU times es the e mechani chanism sm can be reduc duced Mecha hanism nism reduct ction ion throu

ugh

gh necess cessity ty analys ysis Visu sual al analys ysis is of the e reacti ction

n sc

schem heme e throu

ugh

gh flow w analys ysis Stea eady dy state e reduc ducti tion

n through
ugh life-ti

time me analys ysis s

Mechanism nism reducti ction

n

Flow analysis for n-heptane decomposition

SLIDE 13

Mechanism nism Reducti ction

n through
ugh necess

ssity ty analysi ysis

Flow w + sensi nsiti tivi vity ty analys ysis s us used ed to det etect ect the e most t un unnecess necessary y sp species ies in the e mechani echanism sm Workflo kflow: – Read detailed reaction scheme – Run relevant reactor conditions, with necessity analysis turned on. – Let DARS remove species with necessity lower than your defined threshold value – Check mechanism validity through rerun of relevant reactor conditions 13 13

Mechanism reduction panel – choose reduction limit here DARS workbench – read mechanism, constant pressure and reduce mechanism modules

SLIDE 14

DAR ARS S standa ndard d chemis emistr try y mechanis chanisms ms

– n-heptane – TRF (n-heptane/toluene) – PRF (n-heptane/iso-octane) – Natural gas

Collab labora rati tion

n with

h prof.

f. Lu,

u, Un Univ. . of Conn nnecticut cticut

– n-dodecane – PRF (n-heptane/iso-octane) – Biodiesel – DME – Ethanol – Natural gas

An Any CHEM EMKIN KINTM

TM forma

rmatt tted ed mechanis chanism m from m litera rature re can be us used

Chemistr mistry mecha hanis nisms ms

Flow analysis for n-heptane decomposition

SLIDE 15

With h DAR ARS v2.10 0 you can expor port

– ECFM-3Z single/dual fuel libraries (STAR-CD) – ECFM-CleH single/dual fuel libraries (STAR-CD) – PVM-MF single/dual fuel libraries (STAR-CD) – FGM libraries (STAR-CCM+) – Soot libraries (STAR-CD and STAR-CCM+)

Straigh ightf tfor

rward

d parame meter r sp speci cification, ication, designe gned d for each h librar ary y type

– Set up a full library calculation in less than 10 minutes.

Librar rary generat eration ion

SLIDE 16

Par Parallelliza ellizati tion

n

Comma mmand nd line e execut cution ion of calcula ulati tions

ns for

aut utomat mated ed workflo kflows ws

– Use the GUI to set up the calculation – Export case folders and files – Execute calculations from command line

Run on clusters
Automate workflow through scripting

Librar rary generat eration ion

Selection of number of processors to use in GUI ECFM-TKI library generation from command line

SLIDE 17

ECFM FM-3Z 3Z single/du gle/dual al fuel l librari raries es

DARS RS v2.10 0 can n export t ECFM-3Z 3Z TKI auto- igniti ition

n librarie

aries for STAR AR-CD CD

– Constant pressure calculations using complex chemistry

Dual al fuel / single le fuel Specify fy rang nges es and nd grid in T, P, phi, EGR R and nd fuel fract ctio ion Librar ary y set et up ~ 10 min Librar ary y calcu cula lati tion

n: ~ 3 h on 16 cores for singl

gle e fuel librar rary

17 17

Igniti tion dela lay y times s for straig ight t chain in hyd ydroca rocarbo rbon fuel l The gas s comp mposi siti tion panel, l, use sed for r speci cifi fica cati tion of para rame meter ter range and grid id

SLIDE 18

ECFM FM-CleH leH single/dua gle/dual l fuel l librari raries es

DARS RS v2.10 0 can n export t ECFM-CleH eH TKI aut uto- igniti ition

n + Equi

uilibrium librium librar rarie ies for STAR AR-CD CD

– Constant pressure calculations + minimization

f Gibbs free energy using complex chemistry

Dual al fuel / single le fuel Specify fy rang nges es and nd grid in T, P, phi, EGR R and nd fuel fract ctio ion Librar ary y set et up ~ 10 + 5 min Librar ary y calcu cula lati tion

n: ~ 9 + 3 h on 16 cores

es for single le fuel librar ary

18 18

The e gas as compo positi sition

n pan

anel, l, used sed for specif cifica icati tion of para ramete ter range and grid id CO equil ilibriu rium mass ss fracti ction as functi ction of equiva ivale lence ce rati tio and temperatu rature re

SLIDE 19

PVM-MF F singl gle/d e/dual ual fuel librari braries es

DARS RS v2.10 can expor

rt

t PVM-MF MF librari braries es for r STAR AR-CD CD

– Constant pressure calculations using complex chemistry

Dual al fuel el / single ngle fuel el Speci ecify fy ranges nges and grid in T, P, phi, EGR and fuel el frac action tion Librar brary y set et up ~ 10 min Librar brary y calc lculat ulation:

n: ~ 50 h on 16 cores

res for single ngle fuel el librar brary

19 19

The gas s composit sitio ion panel, l, use sed for r specif cifica icati tion

f para

ramete ter range and grid id Igniti tion proce cess ss for n-hepta tane combusti stion at diff fferen rent t equiva ivale lence ce rati tios

SLIDE 20

FGM librari braries es

DARS RS v2.10 0 can n export t FGM librari aries es for STAR AR-CCM+ CCM+

– For non-premixed and partially premixed combustion – Constant pressure calculations using complex chemistry

Explore

re combus

busti tion

n of any

y fuel/o /oxidan dant t mixtu ture re

– Any CHEMKIN™ format chemistry can be used

Specify fy param ramet eter ers and nd grid in mixture ture fract ction

n and

d heat t loss ratio tio Choose species for postproces

cessing

ing in STAR AR-CCM+ Librar ary y set et up: ~ 10 min Librar ary y calcu cula lati tion

n:

: ~ 15 min on 16 cores

20 20

The gas compo posi sition ion panel el, used d for

r speci

cificat ication ion of param amet eters ers and grid id CO mass ss fract action ion during ing n-hep eptan ane e combu bust stion

n at

variou ious s equival ivalen ence ce ratios

s

SLIDE 21

Soot t source ce term rm librari braries es

DARS RS v2.10 0 can n export t Soot

t section
nal

al met ethod

d librari

aries es for STAR AR-CD and d STAR AR- CC CCM+

– Flamelets are used to capture turbulence- chemistry interaction

Specify fy rang nges es and nd grid in T, P, EGR and d scalar lar dissipat ation ion rate Librar ary y set et up ~ 10 min Librar ary y calcu cula lati tion

n: ~ 40 h on 16 cores

es for single le fuel librar ary

21 21

The gas s comp mposi siti tion panel, l, use sed for r speci cifi fication cation of paramete rameter r range and grid id Soot t surfa face ce growth wth as functi ction of mixtu ture re fracti ction for r n-hepta tane combusti stion at vario rious s strain rate tes

SLIDE 22

Readi dily ly available able libraries raries - diesel sel

Fuel Reference mixture Type Where to find Diesel 100% n- heptane EFCM-3Z TKI Contact support ECFM-CleH TKI + Equilibrium Contact support PVM STAR-CD v4.22 Soot Contact support 100% n- decane Soot STAR-CD v4.22 Diesel / natural gas dual fuel N-heptane / NG11 EFCM-3Z TKI Contact support ECFM-CleH TKI + Equilibrium Contact support n- heptane/meth ane PVM STAR-CD v4.22 Gasoline / diesel dual fuel PRF12 / n- heptane PVM Contact support

1 1 NG1:

meth thane 94.4 .40 % CO2 0.77 % N2 N2 1.37 % C2H6 3.46 46 %

2 2 PRF1

F1: Iso-octa ctane 95% n-hepta tane 5% 5%

SLIDE 23

Readi dily ly available able libraries raries – gasoli

line

ne + o

ther

er fuels ls

Fuel Reference mixture Type Where to find Gasoline PRF12 EFCM-3Z TKI STAR-CD v4.22 ECFM-CleH TKI STAR-CD v4.22 PVM STAR-CD v4.22 Flame speed STAR-CD v4.22 Soot STAR-CD v4.22 100% iso-

ctane

Soot STAR-CD v4.22 TRF13 Soot STAR-CD v4.22 Gasoline / ethanol dual fuel TRF24 / Ethanol ECFM-3Z TKI STAR-CD v4.22 Laminar flame speed STAR-CD v4.22 PRF12/ E15 PVM Contact support Ethanol E15 PVM Contact support Natural gas methane PVM STAR-CD v4.22

2 2 PRF1:

F1: Iso-octa ctane 95% n-hepta tane 5% 5%

3 3 TRF1:

tolu luene 26 % iso so-octa ctane 60 % n-he hepta tane ne 14 4 %

4 4 TRF2:

tolu luene 45.4 .48 % iso-octa ctane 39.7 .75 % n-hepta tane 14.7 .77 %

5 E1:

1: Ethanol 99% Wate ter 1% 1%

SLIDE 24

DARS S – in in-cyli ylinder nder combustion ustion

SI: two-zone stochastic model
Knock
Combustion
Emissions
DI: stochastic model with fuel

injection

Combustion
Emissions
10
5

5 10 15 20 25 30 0,0 20,0 40,0 60,0 80,0 100,0 0,0 0,2 0,4 0,6 0,8 1,0

Polynomials (4

th order)

Heat Release Exp Sim A,  const. Sim B,  f(CAD)

Crank Angle [deg ATDC] Rate of Heat Release [J/deg]

Mixing Time Sim A,  const. (0.62ms) Sim B,  f(CAD)

Mixing Time [ms]

DI SRM application – heat release rate. [Pasternak et al, SAE 2009-01-0676] SI SRM application – knock prediction. Lines are experiments, markers are calculations

SLIDE 25

Com

mpar

aris ison

n betw

etwee een n fue uels ls

– Effects of blending n-heptane with toluene (Fuel 2) vs. n- heptane (Fuel 1) – Effects of changes the initial pressure and temperature

Constant AFR Chemical effects due to varied EGR

Emission ission mapping ing

SLIDE 26

1D channel nnel mode del in DAR ARS Basic

– Thin film layer approach - transport to washcoat calculated – Surface chemistry in washcoat layer – Gas phase chemistry in gas – Detailed or global chemistry can be used. – Any CHEMKIN format chemistry can be used.

DARS S - cataly alyst st

washcoat Monolith wall

SLIDE 27

DARS S - cataly alyst st

SLIDE 28

DARS S - cataly alyst st

Save time by ana nalysing ysing chemica ical l reac acti tion

ns in

1D before employin ying g full CFD

– Is detailed chemistry needed for the CFD calculation? – Can a reduced scheme be used? – Optimization of chemistry parameters for reduced schemes.

Study dy emission

n conver

ersion

n as func

ncti tion

n of

– Catalyst length – Exhaust gas temperature – Exhaust species composition

For

– TWC – SCR – DOC – LNT – ...

28 28

200 400 600 800 1,000 1,200

30

20 70 120 170 220 Temperature [K] / Concentration (ppm) Time [min]

InletT[K] NO_GasOut NO2_GasOut N2O_GasOut NH3_GasOut

Ammo monia ia SCR R for a temper erature ramp C3H6 H6 inhibi bitio ion of NO oxidati idation

n under

er lean an con

ndit

ditio ions in Nox-stor

rage

e catalyst talyst

SLIDE 29

NH NH3 SCR as fun uncti ction

n of

inlet t ammonia monia conc ncen entrati tration

n

Am Ammoni monia SCR for an ammonia monia ramp.

mp. Inle

let t gas s compos posit ition: ion: 250 ppm NO, , 250 0 ppm NO NO2, , 8% O2, 5% H2O. Temperatu perature: re: 175⁰C Up Upper r panel: el: exper perim iment ent and si simul ulat ation ion by Chalme lmers. s. Lower r panel: el: DAR ARS simula ulati tion

n

Applicat ication ion exam ample le – SCR SCR

29 29

0.00E+00 1.00E-04 2.00E-04 3.00E-04 4.00E-04 5.00E-04 6.00E-04 100 200 300 400 500 600 50 100 150 200 250 300 350 400

InletT[K] NO_GasOut N2O_GasOut NH3_GasOut NO2_GasOut

Time [min] Temperature [K] Molefraction

SLIDE 30

Application example –

Full powertrain (including aftertreatment) emission

control

In-cylinder combustion

Three-way-catalyst (TWC)

Piping

Pressure trace for Φ= 0.98, 1.00, 1.02

Φ oscillation influence on mass fraction

f CO in & out the pipe

TWC in inle let & outlet et CO and NO mass ss fract action ions, s, at Φ oscillat illation ion of 1 and 2 Hz

Fröjd jd K., Bjerkbo rkborn rn, , S., Perlma lman, C., Mauss, ss, F., DEER R 2011

SLIDE 31

Global bal chem emist stry y optimization imization Cataly lysis sis Libr brar aries ies for CFD D – new in D n DARS S v2.10! 0! Mecha hanism nism reduct ction ion Chem emist stry y analys ysis is

Summa mmary

... . to help p you u un under ersta tand nd and efficie icientl ntly y us use com

mple

lex x chem emistr try

SLIDE 32

Thank k you for your r attention ention

Down wnload load DARS S v2.10 10 from

m the Steve