The use of COMSOL for Building Constructions Engineering regarding Heat and Moisture transport Schellen, H.L.; van Schijndel, A.W.M.; Briggen, P.M.

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1 Th us of OMSOL for Buldng onstructons Engnrng rgardng Hat and Mostur transport Schlln, H.L.; van Schjndl, A.W.M.; Brggn, P.M. Publshd n: Europan OMSOL onfrnc, Hannovr, 008 Publshd: 01/01/008 Documnt Vrson Publshr s PDF, also known as Vrson of Rcord (ncluds fnal pag, ssu and volum numbrs) Plas chck th documnt vrson of ths publcaton: A submttd manuscrpt s th author's vrson of th artcl upon submsson and bfor pr-rvw. Thr can b mportant dffrncs btwn th submttd vrson and th offcal publshd vrson of rcord. Popl ntrstd n th rsarch ar advsd to contact th author for th fnal vrson of th publcaton, or vst th DOI to th publshr's wbst. Th fnal author vrson and th gally proof ar vrsons of th publcaton aftr pr rvw. Th fnal publshd vrson faturs th fnal layout of th papr ncludng th volum, ssu and pag numbrs. Lnk to publcaton taton for publshd vrson (APA): Schlln, H. L., Schjndl, van, A. W. M., & Brggn, P. M. (008). Th us of OMSOL for Buldng onstructons Engnrng rgardng Hat and Mostur transport. In Europan OMSOL onfrnc, Hannovr, 008 (pp. 1-8) Gnral rghts opyrght and moral rghts for th publcatons mad accssbl n th publc portal ar rtand by th authors and/or othr copyrght ownrs and t s a condton of accssng publcatons that usrs rcogns and abd by th lgal rqurmnts assocatd wth ths rghts. Usrs may download and prnt on copy of any publcaton from th publc portal for th purpos of prvat study or rsarch. You may not furthr dstrbut th matral or us t for any proft-makng actvty or commrcal gan You may frly dstrbut th URL dntfyng th publcaton n th publc portal? Tak down polcy If you blv that ths documnt brachs copyrght plas contact us provdng dtals, and w wll rmov accss to th work mmdatly and nvstgat your clam. Download dat: 05. Jan. 019

2 Excrpt from th Procdngs of th OMSOL onfrnc 008 Hannovr Th us of OMSOL for Buldng onstructons Engnrng rgardng Hat and Mostur Transport H.L. (Hnk) Schlln, A. W. M. (Jos) van Schjndl * & P. M. (Ptra) Brggn Endhovn Unvrsty of Tchnology *orrspondng author: P.O. Box 513; 5600 MB Endhovn; Nthrlands, A.W.M.v.Schjndl@tu.nl Abstract: Huntng Lodg St. Hubrtus s on of th most promnnt Dutch buldngs from th arly twntth cntury. It s a prsrvd natonal monumnt of xcptonal cultural and hstorcal ntrst. Ths s why th Dutch Govrnmnt Buldng Agncy has xprssd ts concrn about th obsrvd mostur damag n th towr of th buldng. Th man objctv of ths study was to map th causs of th mostur problms n th towr and to rcommnd possbl solutons to rpar th damag whlst prvntng furthr dtroraton. An xtnsv study of wnd and wnd-drvn ran (WDR) was conductd to provd nsght nto th mostur load of th buldng facad, usng masurmnts and FD (omputatonal Flud Dynamcs) smulatons. Th followng damag catgors ar dstngushd: fflorscnc, crackng, solng, most spots, mchancal damag and bologcal growth. It s concludd from ths study that a conncton xsts btwn th ran load of th facads and th damag on th nsd, snc most damag s obsrvd on th ntror surfac of th facad that s most subjctd to WDR. It s concludd that th mostur problms ar ndrctly dpndnt on th WDR load. Th ran pntrats to th ntror at placs of nadquat dtalng and thrfor causs damag manly nar opnngs n th facad and on th nsd of th facad blow balcons. It s of grat mportanc to mprov th dtalng of th jonts of th dffrnt buldng lmnts. Bcaus of th dffculty to solv th problms concrnng ran pntraton narby opnngs n th sold outr walls by mprovng th dtalng of th frams whlst mantanng th authntc charactr of th facad, t s furthrmor rcommndd to us a mostur-rsstant rstoraton plastr n th towr that can wthstand th crystallzaton of salts wthout causng damag. Th OMSOL softwar was usd for modlng th mostur transport through th walls of th towr. ywords: Drvng ran, mostur problms, hat and mostur transport, masurmnt, smulatons 1. Introducton Huntng Lodg St. Hubrtus s stuatd n th mdst of th xtnsv natural rsrvs of th Dutch Natonal Park D Hog Vluw (Fgur 1). Th Huntng Lodg was bult btwn 1916 and 19 by Holland s most wll-known archtct from that tm: H.P. Brlag. It s on of th most promnnt buldngs from th bgnnng of th twntth cntury and s notd n th top 100 lst of Dutch monumnts. Th floor plan of th brck structur s charactrzd by th towr n th mddl of th buldng wth a hght of ovr 30 mtrs and by th wngs that strtch out dagonally. Huntng Lodg St. Hubrtus s part of th Dutch cultural hrtag and s stat proprty. Th hstory of mostur rlatd problms n th Huntng Lodg s qut long. Snc th dtals of th buldng ar vry old and rathr complcatd for th tm n whch thy wr dsgnd, th walls of th towr ar sold brck and th fact that thr s lmtd hatng n th towr, on can xpct that thr wll b som mostur problms n ths hstorc buldng. Th frst svr mostur problms n th Huntng Lodg occurrd only twnty yars aftr th complton of th buldng, n th prod Fgur 1. Huntng Lodg St. Hubrtus. A layr of concrt that would slow down th mostur transfr through th constructon has bn appld on th nsd of th walls n ths

yars, bcaus of problms wth ran pntraton and condnsaton on th nnr surfac. Th ran load of th southwst facad of th buldng has bn masurd and smulatd by Brggn (007) (Fgur 5).

3 yars, bcaus of problms wth ran pntraton and condnsaton on th nnr surfac. Th ran load of th southwst facad of th buldng has bn masurd and smulatd by Brggn (007) (Fgur 5). Ths papr comprhnds th hat and mostur transport nsd th walls of th towr. Fgur 3 shows a cross-scton of ths walls, consstng of two matrals: brck and concrt.. Inspcton of th mostur damag Th damag on th nsd of th towr, and whr possbl also on th outsd, s systmatcally nspctd. Th locaton and typ of ach mostur problm ar documntd n a tabl, llustratd wth a pctur of th damag. Th mostur problms that manfst thmslvs n th towr of th Huntng Lodg can b dvdd n th followng catgors: fflorscnc, crackng, solng, most spots, mchancal damag and bologcal growth. A pctur of th typcal mostur damag that occurs n th towr s shown n Fgur. damag on th mddl and on th sds of th facad. Most damag occurs nar opnngs n th facad and on th ntror surfac of th facad blow balcons. Th nspcton of th damag nabls a thorough assssmnt of th possbl causs of th mostur problms. Ths assssmnt wll b vry usful for rcommndng solutons that rpar th damag whlst furthr dtroraton s prvntd. Although an ndcaton of th causs of th damag s alrady gvn by th nspcton, t s vry mportant to support ths xpctatons by HAM smulatons basd on accurat WDR boundary condtons. An xtnsv wnd, ran and wnd-drvn ran study was carrd out to dtrmn th WDR boundary condtons. Ths study conssts of masurmnts and numrcal smulatons of WDR and s outlnd n Brggn (007). 4. Masurmnts Th data st s part of th masurmnt program at th Huntng Lodg St. Hubrtus st, prformd durng by Brggn (007). Dtals of ths projct can b found thr. On of problms smd to b hgh mostur contnts at th nsd surfac of th façad of th towr. Th constructon of ths façad s shown n fgur 3. Fgur. Mostur damag at th nsd of th towr Rgardng th locaton of th damag t can b concludd from th nspcton that most damag occurs on th ntror surfac of th south-wst facad of th towr. Snc th prvalng wnd drcton n th Nthrlands s south-wst, whch mans that th south-wst facad of th towr s subjctd to wnd-drvn ran th most, thr appars to b a conncton btwn th ran load of th facad and th damag on th nsd. Thr ar no clar dffrncs btwn th damag on lowr or hghr floors or btwn th Fgur 3. Horzontal scton of th buldng façad Th outsd clmat condtons wr masurd by a wathr staton wthn 50m from th buldng. S fgur 4. Th nsd ar tmpratur and rlatv humdty wr masurd usng standard qupmnt (s fgur 6). A rprsntaton of nsd surfac condtons was obtand by placng a small box (5cm x 5cm x 1cm) aganst th wall and masur th ar tmpratur and rlatv humdty nsd. Th stmaton of th masurmnt rror of ths mthod s lft ovr for futur rsarch.

surfac, supposd to b n qulbrum wth th wall.

4 Fgur 4. Poston of th mtorologcal mast (masurmnt of rfrnc wnd spd and rfrnc wnd drcton) and th horzontal ran gaug, poston 1. Fgur 6. Masurmnt of th surfac tmpratur and rlatv humdty at th nsd surfac of th towr, usng a closd box, connctd to th nsd surfac, supposd to b n qulbrum wth th wall. Th nput data consst of th masurd tm srs of th ndoor and outdoor clmat as prsntd n fgurs 7 and 8. Fgur 5. Spatal dstrbuton of th catch rato for th ran vnt of Sptmbr 17 th, 007. Th xprmntal rsults at th locatons of th wnd-drvn ran gaugs ar shown on th lft; th numrcal rsults ar shown on th rght. Fgur 7. Th masurd ar tmpraturs (top) and calculatd vapour prssurs (bottom, from masurd T/RH)

5 Wth Fgur 8. Th masurd solar rradanc (top) and ran ntnsty (bottom) 5. Modlng As mntond n Scton 1, a comprhnsv modl capabl of smulatng th rqustd data s rqurd. Amongst othr possblts, th multphyscs modlng approach of van Schjndl (007) s slctd. A gudln on how to mplmnt up to 3D hat ar and mostur (HAM) transport modls usng OMSOL (008) s alrady provdd (van Schjndl 006). Thr ar two major xtnsons to ths work, dscrbd n th followng sctons: Frst, th mplmntaton of LPc as mostur potntal for ncludng both vapour and lqud transport and scond, th mplmntaton of matral and boundary functons for calculatng th PDE coffcnts from th matral proprts. Th mplmntaton of th two nw xtnsons was vrfd usng th HAMStad bnmark 1 (Hagntoft t al 00). 5.1 Implmntaton of LPc potntal Th hat and mostur transport n a sold can b dscrbd by th followng govrnng PDEs: T LPc LPc= T = ( 11 T + 1 LPc) t = ( 1 T + LPc) t 10 log( Pc) T 11 1 LPc 1 = ρ c = λ M w = llv δ p φ Psat, ρ a RT w = Psat = δ p φ T M w = δ p φ Psat, ρ RT Whr t s tm [s]; T s tmpratur [ o ]; P c s capllary prssur [Pa]; ρ s matral dnsty [kg/m 3 ]; c s spcfc hat capacty [J/kg]; λ s thrmal conductvty [W/m]; l lv s spcfc latnt hat of vaporaton [J/kg]; δ p vapour prmablty [s]; φ s rlatv humdty [-]; Psat s saturaton prssur [Pa]; M w = [kg/mol]; R = [J/mol]; ρ a s ar dnsty [kg/m 3 ]; w s mostur contnt [kg/m 3 ]; s lqud watr prmablty [s]. Th ()ntrnal boundary condtons ar: q = α ( T ( t) T ) g = β ( p ( t) p) Th ()xtrnal boundary condtons ar: q = α ( T ( t) T) + q g = β ( p ( t) p) + g solar ran ( t) ( t) [ W / m a [ kg / sm ], ] [ W / m ], [ kg / sm ] 5. Implmntaton of advancd matral and boundary functons Th scond xtnson s th mplmntaton of advancd matral and boundary functons usng Matlab. Ths functons ar usd to convrt masurabl matral proprts such as, φ, δp and λ whch ar dpnt on th mostur contnt nto PDE coffcnts whch ar dpndnt on

6 th LPc and T. Ths s schmatcally shown n fgur 9. Fgur 9. Th convrson from masurabl matral proprts nto PDE coffcnts For ach matral and at ach pont th vapour prssur can b calculatd usng a smlar corrspondng functon. 6. Rsults Th matral databas of DELPHIN (008) s usd to provd matral proprts. For brck, th Brck matral proprts of DELPHIN ar usd wth constant ρ= 1700; c = 840; λ = 0.85 and varabl mostur proprts usng th tabls. For concrt, th Lm plastr proprts of DELPHIN (ρ= 1800; c = 840; λ = 1.05) ar usd n th sam way. From ths data, th PDE coffcnts wr dtrmnd smlar to fgur 9 and togthr wth th boundary condtons mplmntd usng th OMSOL modl of Scton 5. Fgur 10 and 11 show th rsults. Fgur 10. Th masurd and smulatd nsd surfac tmpratur. Fgur 10 shows that th smulatd nsd surfac tmpratur s alrady qut clos to th masurd on. Fgur 11. Th masurd and smulatd rlatv humdty at th surfac. Th smulatd rlatv humdty at th nsd surfac of fgur 11 sms to b lss clos to th masurd on compard to th prvous fgur. 7. onclusons Th provdd OMSOL PDE modl for smulatng hat and mostur transport n constructons s valdatd wth masurmnts. Ths modl wll b usd to valuat th long trm durablty of th currnt constructon and altrnatv dsgns. 8. Rfrncs Brggn P.M. (007). Ondrzok naar d oorzakn van d vochtschad aan d torn van Jachthus St. Hubrtus. Mastr Thss, Unt Buldng Physcs and Systms, Endhovn Unvrsty of Tchnology, th Nthrlands, [n Dutch]. Hagntoft, -E. t al, 00a, HAMSTAD WP Modllng,Vrson 4. Rport R-0:9. Gothnburg: halmrs Unvrsty of Tchnology Hagntoft, -E t al, 00b, Fnal rport: Mthodology of HAM-Modllng. Rport R- 0:8. Gothnburg: halmrs Unvrsty of Tchnology Schjndl A.W.M. van (006), Hat, Ar and Mostur onstructon modlng usng OMSOL wth MatLab, Modlng gud vrson 1.0, Procdngs of th OMSOL Usrs onfrnc 006 Endhovn Schjndl A.W.M. van (007), Intgratd Hat Ar and Mostur Modlng and Smulaton,

7 Bouwstnn 116, ISBN: , Endhovn Unvrsty of Tchnology DELPHIN_008, r) HAMLab 008, OMSOL_008, Wkpda 008, 9. Acknowldgmnts Ths rsarch s fundd by th Dutch Govrnmnt Buldng Agncy. Thr fnancal contrbuton s gratfully acknowldgd. Th authors wsh to xprss thr grattud for th knd assstanc and hosptalty of th managrs of th Huntng Lodg and th staff of th Natonal Park D Hog Vluw. Apprcaton s also xprssd to th staff of th Laboratory of th Unt Buldng Physcs and Systms of Endhovn Unvrsty of Tchnology for thr valuabl assstanc wth th dsgn and nstallaton of th masurmnt st-up.

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