Comple plex x chemis mistr try y with h DARS Ka Karin Fröjd
Why DARS? S? 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 oices ces, incl cluding ng chem emical al effec ects ts • Fast ster er and cheaper eaper desi sign cycles cles • Evaluat valuation on of enti tirel rely new desi signs gns
Why comple lex chemis istr try? y? To capture ure chemica emical l effects ects Emissi Em sions ons 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 Soot t surface face growth wth as funct ctio ion of mixtu ture re fract ction ion for r n- Igniti tion dela lay y times s for diff ffere rent natu tural ral gas s quali liti ties heptan tane comb mbust stio ion at variou ious s strain in rate tes
What is DARS? S? Standalone ndalone softw tware are for r 0D and 1D analys yses es of chemical emical reacti ctions ons Chem emist stry y analys yses Mecha hanism nism reduct ction ion Idealized ealized react ctor ors – Ignition delay time – Emission production – Flame speed calculations Libr brar ary y generati neration on 1D & 0D PDF mode dels s for in-cyl cylinde inder r combus mbusti tion on 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+ and STAR-CD an CD 4
DARS 5
Chemistr mistry analysi lysis Impor mport t any mechani chanism sm in DAR ARS S Basic An Analys yse e the e chemist emistry y in react ctor ors s and flames mes Un Under derst stand and reacti ction on pathways ys throu ough gh species cies flow w analys ysis Igniti tion dela lay y times s as functi ction of tempe perat ature for n-he hepta tane CO producti ction in fuel rich ch combusti stion of n-hepta tane n-hepta tane deco composit sitio ion
Ignit ition n delay y times mes n-he hepta tane ne comb mbusti tion, on, p=20 0 bar
Lamin minar ar flame me speeds eds Lamina nar flame e speeds eds with detail ailed ed chem emistr istry CH2O Minor r (291 species, ecies, 3081 1 reactio tions) ns) for a mixtur ure e of speci cies 95% iso-oc octane, ane, 5% n-hept eptane ane in air HO2 C2H2 Fuel l & main n Laminar flame me speed as function tion of species cies unburned temperatu ture and p pressure CO2 CH4 CO OH Laminar flame me speed as function tion of equival alenc nce rati tio and u unburned temperatu ture The laminar flame speeds generated by DARS can be used by 8 the PCFM model in STAR-CCM+
Emission ission mapping ing Soo oot t for n-hep hepta tane ne combust mbustion, ion, p=50 bar
Emission ission mapping ing NO for n-he hepta tane ne comb mbust stion, ion, p=50 bar
Emission ission mapping ing CO for n-hept heptane ane combust mbustion ion, , p=50 0 bar
Mechanism nism reducti ction on To avoi oid d large e CPU times es the e mechani chanism sm can be reduc duced Mecha hanism nism reduct ction ion throu ough gh necess cessity ty analys ysis Visu sual al analys ysis is of the e reacti ction on sc schem heme e throu ough gh flow w analys ysis Stea eady dy state e reduc ducti tion on through ough life-ti time me analys ysis s Flow analysis for n-heptane decomposition
Mechanism nism Reducti ction on through ough 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: DARS workbench – read mechanism, constant pressure and reduce mechanism modules – 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 Mechanism reduction panel – choose 13 13 reduction limit here
Chemistr mistry mecha hanis nisms ms 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 on 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 KIN TM TM forma rmatt tted ed mechanis chanism m from m litera rature re can be us used Flow analysis for n-heptane decomposition
Librar rary generat eration ion 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 orward 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 Parallelliza Par ellizati tion on Comma mmand nd line e execut cution ion of calcula ulati tions ons for aut utomat mated ed workflo kflows ws – Use the GUI to set up the calculation – Export case folders and files Selection of number of – Execute calculations from command line processors to use in GUI • Run on clusters • Automate workflow through scripting ECFM-TKI library generation from command line
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 on 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 on: ~ 3 h on 16 cores for singl gle e fuel librar rary 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 17 17 Igniti tion dela lay y times s for straig ight t chain in hyd ydroca rocarbo rbon fuel l
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 on + Equi uilibrium librium librar rarie ies for STAR AR-CD CD – Constant pressure calculations + minimization of 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 on: ~ 9 + 3 h on 16 cores es for single le fuel librar ary The e gas as compo positi sition on pan anel, l, used sed for specif cifica icati tion of para ramete ter range and grid id 18 18 CO equil ilibriu rium mass ss fracti ction as functi ction of equiva ivale lence ce rati tio and temperatu rature re
PVM-MF F singl gle/d e/dual ual fuel librari braries es DARS RS v2.10 can expor ort 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: on: ~ 50 h on 16 cores res for single ngle fuel el librar brary The gas s composit sitio ion panel, l, use sed for r specif cifica icati tion of para ramete ter range and grid id 19 19 Igniti tion proce cess ss for n-hepta tane combusti stion at diff fferen rent t equiva ivale lence ce rati tios
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 ore combus busti tion on of any y fuel/o /oxidan dant t mixtu ture re – Any CHEMKIN ™ format chemistry can be used The gas compo posi sition ion panel el, used d for or speci cificat ication ion of Specify fy param ramet eter ers and nd grid in mixture ture param amet eters ers and grid id fract ction on and d heat t loss ratio tio Choose species for postproces ocessing ing in STAR AR-CCM+ Librar ary y set et up: ~ 10 min Librar ary y calcu cula lati tion on: : ~ 15 min on 16 cores 20 20 CO mass ss fract action ion during ing n-hep eptan ane e combu bust stion on at variou ious s equival ivalen ence ce ratios os
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