Nghign cufu & Trao doi ANH HU''''O''''NG CUA Dp CAO NGUON THAI DEN LAN TRUYEN CHAT 6 NHIEM TRONG LOP BIEN KHJ QUYEN ThS Nguyin Minh Tru''''ang\ ^Phbng Thi nghiem Dy bao Thai ti lt va Khi hau ThS Vu Thanh Hang^[.]
Nghign cufu & Trao doi ANH HU'O'NG CUA Dp CAO NGUON THAI DEN LAN TRUYEN CHAT NHIEM TRONG LOP BIEN KHJ QUYEN ThS Nguyin Minh Tru'ang\ - ^Phbng Thi nghiem Dy bao Thai tilt va Khi hau ThS Vu Thanh Hang^-^Bp mbn Khi tupng Khoa Khi tugng-Thuy van-Hai duang hpc Dai Hpc Khoa Hoc Ty Nhien T K)ng bai bao trwdc day cua cimg tac gia, phwang trinh lan truyin chit d nhiim dwac dwa vao thir nghiem giai ciing vdi md hinh HOTMAC sir dung sa dd sai phan in luan hwdng Trong nghien ciru hai phwang an cao ngudn thai dwac ap dung di tinh sw anh hwdng ciia cao ngudn thai din tan truyin nhiim lap bien quyin Cac kit qua md phdng cho thiy dang phan bd ndng chit nhiim d cao 102 m la giing d mat dit vi th diim cd ndng cue dai la khac Ngoai ra, kit qua md phdng sd cung cho thiy la tai cac khu cong nghiep niu ngudn phat thai mot luang lan chit d nhiim thi nhit thiit phai xay dng khdi cd cao dii lan di giim ndng phia xudi ddng Ma dau Trong nhQ'ng nam gin day eae hoat dbng kinh t l , nhit la cbng nghiep, phat triln manh me, van de b nhilm mbi truong va cac he luy ciia nb da dupe cac nha khoa hpc va quan ly dat cip thiet Dy bao nong dp chit b nhiem quyIn la bai toan phu'c tap vi nb phu thubc vao cac dilu kien tupng (gib, nhiet db, roi ) cung nhu nhQ'ng phan LPng hoa hpc eb thi xay giCra eae chit b nhilm Sy tuong tae giQ'a cac chat b nhilm va eae biln quyIn lam eho bai toan tra nen rit phu'c tap Vi du, cuong dp cac phan u'ng hoa hpc giCra cac chit b nhilm cb the phu thubc vao cuong dp rbi, ngupc lai cae chat b nhilm, nhu C02, eb the hip thu bu'c xa mat trbi va lam thay doi nhiet dp be mat [2, 4] Tuy nhien, vol cae bai toan han ngin, d l dan gian vin d l cb the xem cae chit gay b nhilm la tra va thu dbng vai mbi trub'ng De danh gia tae dbng mbi trubng khbng eiia mot dy an phat trien cbng nghiep, cbng trinh giao thbng van tai, hay danh gia miPc dp b nhiim mbi truong qua khip hay tuang lai diu can phai dy bao dupe mu'c db lan truyen chat b nhilm va tinh toan nong dp cOng nhu biln thien theo thai gian cua chung Viec SLP dung mb hinh toan d l giai bai toan lan truyin chit b nhilm mbi truong khbng dupe phat triln manh tu" nhQ-ng nam 1970 Cac mb hinh thuang gap eb the la mb hinh thong ke kinh nghiem dya tren eo so ly thuylt Gauss hoac cac mb hinh so cb nhilu uu diem han [3] Vbi mot dy an phat triln khu cbng nghiep cu thi, dya tren ca so cac tai lieu ky thuat cb thi danh gia dupe toe dp phat thai mot chit eu the nao db Nhu vay, eb t h i xay dyng cae kjeh ban dat ngubn thai (hay vi tri va dp cao ong khbi) dilu kien gib thinh hanh tai dia phuong d l xem xet mu'c dp anh hubng eua khu cbng nghiep din eae khu vyc dan cu lan can Day la viec lam cin thilt vi nb giiip tranh dupe viec phai chi tra rit lan eho cbng tac khic phuc cac sy c6 mbi truong Vol nhan dinh nhu vay, nghien CU'U cac tae gia da dua vao mb hinh HOTMAC phuang trinh bao toan nong dp chit b nhiem va phat triln ma nguon de giai dong thai bai toan cung vol mb hinh Ib'p bien quyIn, su' dung so sai phan an luan hubng tuong ty nhu each giai ap dung cho mb hinh lop bien Chi tilt hon ve HOTMAC cb thi xem cac tai lieu tham khao trich dan [1, 5, 8], Cae phuong Ngubi phan bien: TS Du'ang Hong San 28 Tap chi Khi tiTg'ng Thuy van * Thang 12/2008 Nghien cufu & Trao doi trinh, cau hinh mien tinh, cac dilu kien ban diu va dilu kien bien se dupe trinh bay ngin gpn cac muc dubi day gib trung binh va cac phuong trinh bao toan dbi vbi nhiet dp thi vj L va ti sb xao trpn eua lupng nubc tong cbng QW cb thi dupe vilt dubi dang sau [1], He phu-ang trinh f"*^' ^^^ cac phuong trinh chuyen dbng vilt cho tie dp dt ^ (i: dx ^ = -.f{U-U^) + dt ^ (2; o: v^ (4: Trong db (x, y, z) la tpa dp Oe cae; t la thai gian; U va V la eae phin gib ngang theo huong x va y tuang u'ng; f la thbng so Coriolis; va toan tu' b v l trai cua cac phuang trinh tren dupe djnh nghTa nhu theo Yamada [4], [5], [6], [7] van tic thing dipng W nh$n dupe bing each tich phan phuang trinh lien tuc cho chit Ibng khbng n6n duac sau dU dy dW ^ — -f- — + =0 dl dt dy dx (5) dz cac phin gib dja ehuyin Ug va Vg; va eae he so khuleh tan ngang Kx Ky va Kxy dupe xac dinh i.{'>''i)-i dl dx dx ( ,_ d[q'-li)\ K dy dx vk ' dx K, m dx Trong db ; I la qui mb dp dai xoay rbi; B1, El, E2, Sq va SI cac hing so thyc nghiem dupe xac djnh tu' cac nghien CU'U phbng thi nghiem Cae phuang trinh tr§n cung bao gom cae thbng lupng roi khac nhu mf.vM',^/„it' va 0,"^^ Cac dai (7) q_ dy J dV vw -^^ -H Pgw 9^ cz -dU cz V d_ K dy (6) dz Mb hinh dbi hbi cae nghiem dy bao doi vbi cac phuang trinh nang lupng roi va qui mb dp dai xoay roi, gom — dV dz dt^^ dy o \ i s' I , ^cz- dz \ l+£ n + IE, — dU tw — dz 2\ (8) ^Icz lupng eb thi dupe bieu diln qua cac so hang eua U, V, Qw va L; vbi cac phuong trinh khac va cac mb ta ehi tilt hon dupe trinh bay [4], [5], [6], Phuang trinh bao toan nong db chat b nhilm Tap chi Khi ti/^ng Thuy van * Ihang 12/2008 29 Nghien cufu & Trao doi gia tri nbng dp tren bien xung quanh dupe re oai suy dC ^dC ^^dC „dC d I - , ^ — + {] — + V — + W — = — I - M'c) -h dt dx dy dz dz (9) theo cbng thu'c CQ = 20,., - C_2, t^ong db chi -n chi d i l m bien, ehi sb -1 va -2 chi diem each bien va nut luai Tai dinh mb hinh nbng dp dwac eho bing Trong db p h i n rbi ngang dup'c bb qua, C la nong dp chat b nhilm; S la ngubn phat thai Thanh p h i n thbng lupng dupe xip ly tuang ty nhu thbng lupng nhiet rbi [4], [8] Mien tinh, dieu kien bien va dieu kien ban dau Tai mat d i t , c h i t b n h i l m khbng t h I m nen ^ = o[4] cz Trong nghien CU'U nay, so sai phan hQ'u han la so db an luan hubng (Alternative Direction Implicit ADI), vol sai phan t i l n theo thai gian va sai phan Nhu da nbi a tren, v i n d l lan truyin c h i t b trung tam theo khbng gian Mb hinh b i t d i u tich nhiem lop bien quyIn anh huang rat Ion phan luc 7h theo gio dia phuang, 20/8, va kit d i n d i l u kien song eiia nguoi Ngoai ra, c h i t b luc sau 24 h tich phan Nhu vay, thb'i gian tich phan nhilm cb the lam ton hai nghiem trpng he sinh thai la mot ngay, vol mue dich chu y l u la n i m b i t cac cQng nhu cac khu bao t i n sinh quyIn nhay cam Vi bien doi cb chu ky dem Cac k i t qua thu dupe vay, viec dy bao/mb phbng lan truyin chat b nhilm nghien ciru d u a c thyc hien tren eo so cae lap dual cung ciia b i u quyIn gay p h i n m i m s i n eb dual dang ma ngubn bing ngbn bbi cae khu cbng nghiep la r i t quan trpng nhung a ngQ' FORTRAN, tinh hubng mb phbng va bai toan Viet Nam chua'cb nhilu eae nghien CU'U v l v i n d l lan truyin c h i t b n h i i m cac tac gia xay dyng Do vay nghien CU'U ly tuang hoa tac Ket qua va nhan xet gia SLP dung mot m i l n tinh toan bao gom 30 x 21 x a Trw&ng gio 21 d i l m lubi theo hubng x, y va z tuong ipng Tam mien tinh dupe gia thilt dat tai 21°5N-105°7E Buoc luoi ngang la 0,020 kinh vT (2,22 km) C i u hinh luoi thing du'ng eb dang logarith t u y i n tinh va mye tren ciing eb dp cao khoang km so vbi mat dit Lubi thing du'ng huong xuong duoi doi vol d i t bao gom 11 myc, dp sSu eye dai la 1m, bao dam mb phbng tot cae qua trinh b l mat Nhu da de cap a tren, tai thbi diem ban dau, luc 7h sang gib dia phuang, trubng gib dupe cho la taytay nam vbi van tbc 10 m/s tai dinh mb hinh Sau 4, 8, 12, 16, 20 va 24 gia tich phan, truong gib tai cac dp cao 0,2 m, 38,5 m, va 102 m (tuong u-ng vbi cac mye mb hinh thip 2, 10 va 11) dupe dua hinh 1-3 D i l u kien ban d i u dupe gia t h i l t la dbng n h i t theo phuang ngang doi voi t i t ca cac trubng, db truong gib eb dang loga va cac truong khac dupe thilt lap tuong ty nhu cac nghien CU'U < {< < ^^ i ' * I i \ i * \\ [1] va [6] Trubng gib tai muc tren cung dupe eho la »< ^ cb t i c db lOm/s vol hubng tay-tay nam va dupe gan i i b i n g khbng tai mat dat Nhiet dp b l mat d i t ban d i u la 250c va tang xubng phia dubi tbi 26°C tai mye (a) ii < < sau nhit va dupe giCp khbng doi theo thai gian Cae d i l u kien bien xung quanh thyc hien mb hinh la d i l u kien bien phat xa, giup tranh dupe sy phan xa cua cac nhieu tinh toan tu' cae khu vyc bien ben vao tam cua mien tinh [4] Nong dp c h i t b n h i i m liic d i u dupe cho b i n g Ngubn d i l m ly tuong hoa dupe gia thilt dat tai diem cb tpa dp tren lubi ngang tai d i l m (9, 5), dp cao 38,5 va 12 m Cae 30 Tap chi Khi tu'(/ng Thuy van * Thang 12/2008 (b) Nghien cufu & Trao doi 1t H i ( 1I M 1t (c) H H i < H M H M H I H n H H t)!M H I t< i H t i « * H t i < I H i I M H H !H H n !***< i i < (H ' • I I 11 tM * U* f Hinh Gidng Hinh 1, ngoai trie tai cao 38,5 m Tuy nhien, nlu so sanh ky han cb t h i thiy tu" mat dit len din dp cao 38,5 m hubng gic thay dbi khbng nhilu so vai lap tu' 38,5 m din 102 m Dilu cho thay tinh phan lap kha rb lap bien quyln MiPC dp quay hubng gib theo dp cao eho thiy su phu thubc vao thai gian va chu ky dem rb rang Trong tai dp cao 0,2 m, gib dupe tri eb huang nam hiu nhu on dinh suit thbi gian tich phan (hinh 1) thi tai dp cao 38,5 m, sau gia tich phan (11 h gia dia phuong) truong gib lech vol gib mat d i t nhilu nhlt (hinh A) Bit diu tu' 15 din 23 h gia dia phuang gib dan quay sang trai va trb lai gin nhu trung vai gib nam tren mat dat (hinh B, C, D) Sang hbm sau, gib bit diu quay sang phai mot lin nQ'a va eb dang nhu tren hinh E, F Kit qua tuong tu cQng se thiy cho dp cao 102m (hinh 3) y/r/W/r/WvWm/7vvvv7V7r/7 7//////////7JJ,//J/.7JJ/,/.////^^/^ 7777/77777777777777777777777/7 7/7/////////////////////////// 7/////////7/////////////////// i i ////////////////////////////// 7//////////77///////////////77 ii I 7/7/////////////////////////// 7//////////////7/7//7/7/////// 7/7/////////////////////////// 7 77 7/77 7/7 7 7 7//V 77 77 7 7 /'/7'/'/v'rr/'/7/////77//////////// ^z:^xzzzz:^z:^/xz:^zzzmz^z^zz^^z r/r/'7r;77r/7r/r/7r/77r7r/r7777 77777777^/7777777777777777777 0'/'/'/'/7/7/7/7/7/////'M/''/7/'/'/'/'/O'/'/'/'/^/'/'/'/'/ W/'^/'/'7'7VVY7^/VVT//V/ //////////// Hinh Gidng Hinh 1, ngoai trie tai cao 102 m 32 Tap chi Khi tu'c.yng Thuy van * Thang 12/2008 Nghien ciJu & Trao 46i Ve eubng db gib, gib cb t i e db y l u n h i t vao bull nen manh me (hay nbi each khac la lam tang tinh trua (hinh IA, 2A, 3A) sau db tang d i n cho den h b i t on dinh dbt nbng b l mat) Dieu chinh la sang hbm sau Nhu vay, theo thai gian bu'c xa mat nguyen nhan d i n d i n viec gib quay manh sang phai trai t i l p tuc dot nbng b l mat d i t d i n den nhiet db theo dp cao vao b u l l trua va eb cuong db y l u nhit mat d i t tang len nhanh ehbng va lam eho cuong db nhu da thiy tren cae hinh 1, hinh va hinh trao doi roi cac lap khbng g i n b l mat tro Hinh Ndng chat d nhiem tai cao 0,2 m sau 4, 12, va 20 h tich phan: ngudn cao 38,5 m (a, c, e) va12m(b, d, f) t h i dbng nghTa vol gia thilt t i e db phat thai tang lien b Trw&ng ndng tuc theo thai gian, thyc te nguon thuang la Trong nghien CU'U nguon phat thai S phuong trinh (8) dupe cho b i n g dan vi nong dp thai gian mot giay, tuong ty nhy [8], cho trubng hpp dp cao ngubn la 38,5 va 12 m Luu y ring S khbng phai la toe dp phat thai ma la toe dp phat thai eho nong db c h i t b n h i i m tai nguon ham cua thai gian, luc tang, luc giam Tuy nhien, vi gay b nhiim la nhe, hoan toan thu dbng vbi mbi trubng khi, vay nghien CU'U ly tuong hoa cac tae gia eho S = , tuong ty [4], v&\ mue tieu chinh la nghien CLPU anh huang ciia db cao nguon thai d i n lan truyen c h i t b nhiim diem tang mot don vi thoi gian s D i l u cb Tap chi Khi tiTc^ng Thuy van * Thang 12/2008 33 /.? Nghien cufu & Trao doi Hinh Gidng Hinh 4, ngoai trir tai cao 102 m Trube hit hay xem xet phan bb theo phuong ngang eua nong db chit b nhiem tai dp cao ngubn thai 0,2 m Hinh mb ta phan bo nong dp theo phuang ngang tren mye sat mat d i t Sy phu hop vai huang gib din tai hien tupng true cua eae khu vyc cb nong dp eye dai nim gin nhu theo huang bic-nam vol ca hai trub'ng hp'p dp cao nguon thai Sau gib tich phan phat hien thiy mot eye tri nong dp tai dilm each xa ngubn khoang 13 km v l phia bic va lech khoang km v l phia dbng eua ngubn thai Hien tupng lech dbng cho thiy van chuyin thing du'ng giu' vai trb thing tri qua trinh lan truyin chit b nhiem xubng mat dit vi nhu da nbi gib Ibp sat mat dat cb huang thjnh hanh nam-bie Cung voi thai gian, truang hop ngubn cao 38,5 m eho dilm ey tn nbng dp din di chuyen len phia bic 34 va on djnh vj tri a lan can bien phia bic cua miln tinh Trong db truong hop ngubn cao 12 m cho diim eye trj nong dp vin nim miin tinh Len din dp cao 102 m, nong dp chat b nhiim giam di rit nhiiu (hinh 5) Tuy nhien, trai vol trubng hpp sat mat dit, phan bo nong dp chit b nhiem tai dp cao la giong ea hai truang hpp cao nguon thai Nhu vay, a eae mye tren dp cao nguon thai, true cua cac khu vue eb nong dp cue dai nim gin nhu trung vai huang gib tai cung thbi dilm, thi hien tinh chu ky dem rb ret Dilu phan anh vai trb eiia binh luu tren cac dp cao Ibn hon dp cao ngubn thai Ket luan Theo cac kit qua mb phbng sb HOTMAC dua Tap chi Khi tu'ong Thuy van * Thang 12/2008 Nghien cufu & Trao doi p h i n 4, mac du ehi la eae mb phbng ly the hien tac dbng eua nb vao khoang tren 100m, tuong hoa nhung eb the k i t luan ring dp cao nguon tuong duong vol db cao ma eae nha tupng hpc phat thai cb anh huang Ion toi phan bo nong dp c h i t tren t h i gibi gpi la "lop b l mat" Cy eae myc tren dp b nhilm g i n mat dit Cu t h i la vol nguon thai cb dp cao ngubn thai, true eua cae khu vyc eb nbng dp eye cao t h i p , d i i m eye dai nong dp cb t h i x u i t hien dai n i m g i n nhu trung vol hubng gib tai cung thoi khbng xa nguon phat thai Truang hop ngubn thai diem va cho thiy chu ky dem rb ret Dieu cb dp cao nhb lubn eho nbng dp c h i t b nhiim nhb phan anh vai trb cua binh luu tren cae dp cao Ibn hon trub'ng hop eb dp cao lan bai vi vol cung S hon db cao ngubn thai = nhung a dp cao t h i p , toe dp gib nhb hon vay Cubi cung, cae k i t qua eiia mb hinh da t h i hien chi can toe dp phat thai nhb cQng du d i thoa man S = Hay nbi each khac, vai ngubn thai c h i t b nhiim Ibn thi nhit thilt phai xay bng khbi cb dp cao Ion d i y nghTa thyc t i l n dang k i va hoan toan cb t h i ap dung cho cac ngubn phat thai d i l m tai cac khu cbng nghiep Khi db p h i n nguon S phuang giam nong dp xubi theo gib thjnh hanh trinh (8), vi du dbi vol mot bng khbi, se phu thubc v l mat tryc giac vat ly cho t h i y mb hinh dupe phat triln bai bao cb t h i mb phbng tbt qua trinh ba chilu van chuyin c h i t b nhilm nhe gay bai mot nguon d i i m lap bien q u y l n Cu the, dp cao Ib'n nhit ma nguon thai ly tuong hoa v i n vao duong kinh ong khbi, t i e dp phut va nhiet dp phat thai Nghien CU'U dupe ho trp bai de tai nghien CU'U CO ban NCCB-705906 Tai lieu tham khao Nguyin Minh Trudng va Vu Thanh Hing, Dwa bai todn lan truyin chit d nhiim vdo md hinh HOTMAC cho lap bien quyin Tap chi Khi twang Thuy van, 568 (2008) 9- 18 Pieike Roger A., Mesoscale Meteorological Modeling (2001) Academic Press Stull Roland B., Boundary Layer Meteorology Yamada T, A Numerical Experiment on Pollutant Dispersion in a (1988) Kluwer Academic Publishers Horizontally-Homogeneous Atmospheric Boundary Layer Atmos Environ., 11 (1977) 1015-1024 Yamada T, A Numerical Model Study of Turbulent Airflow in and Above a Forest Canopy J Meteo Soc of Japan, 60 (1982) 439-454 Yamada T, Simulations of Nocturnal Drainage Flows by a q2i Turbulent Closure Model J Atmos Sci 40(1983)91-106 Yamada T, and S Bunker, A Numerical Model Study of Nocturnal Drainage Flow with Strong Wind and Temperature Gradient J Appl Meteor, 28 (1989) 545- 554 Yamada T, Chih-Yue J Kao and S Bunker, Airflow and Air Quality Simulation over The Western Mountainous Region with a Four-Dimensional Data Assimilation Technique Atmos Environ., 23 (1989) 539- 554 Ta p chi Khi t Uc/ng Thuy va n = Ihang 12/2008 35 ... o[4] cz Trong nghien CU''U nay, so sai phan hQ''u han la so db an luan hubng (Alternative Direction Implicit ADI), vol sai phan t i l n theo thai gian va sai phan Nhu da nbi a tren, v i n d l lan truyin... 38,5 m eho dilm ey tn nbng dp din di chuyen len phia bic 34 va on djnh vj tri a lan can bien phia bic cua miln tinh Trong db truong hop ngubn cao 12 m cho diim eye trj nong dp vin nim miin tinh... todn lan truyin chit d nhiim vdo md hinh HOTMAC cho lap bien quyin Tap chi Khi twang Thuy van, 568 (2008) 9- 18 Pieike Roger A., Mesoscale Meteorological Modeling (2001) Academic Press Stull Roland