Luận văn thạc sĩ toán Giải Tích-Chuyên đề :Phương trình Parabolic phi tuyến trong miền hình cầu
Trang 1KhilO sat phuong trinh parabolic phi tuyin
trang mi~n hinh cdu
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CHUONG4
sV TON T~I, DUYNHA.TvA ON DJNH NGHl~M T-TUANHoAN
Trong chuang nay, chung t6i nghien Clm nghi~m T-tu~n hoan cua
bai toan gia tri bien phi tuySn sau day
(4.1)
(4.2)
(4.3)
(4.4)
Ut-(Urr+~Ur)+F(U)=f(r,t),O<r<l, O<t<T,
lim rur (r,t)
!
< +00, ur (l,t) + h(t){u(l,t) - uo) = 0,
r~O+
u(r,O) = u(r,T),
IIP-z
F(u) =u u,
trong d6 2~ p < 3, Uo lel cac h&ngs6 cho truac, h(t), f(r,t) lelcac ham s6
cho truac T-tu~n hoan theo t, thoa cac giii thiSt sau
(Hz)
(H;)
(H~)
UoE JR,
hE wi"" (O,T), h(O)= her), h(t) ~ ho > 0,
f E CO([0,T}H), f(r,O) = f(r,T).
Nghi~m ySu cua bai toan (4.1)-(4.4) duQ'cthanh l~p nhu sau tu bai toan biSn phan sau:
Tim u E LZ(O,T;V)n L'"(O,T;H) sao cho u' E LZ(o,T;H) va u(t) thoa phuang
trinh biSnphan sau:
(4.5)
f(u'(t), vet))dt + J[(ur(t), vr(t)) + h(t)u(l, t)v(l,t)}it
T + f(F(u(t)), v(t))dt
°
= f(f(t), v(t))dt + uo fh(t)v(l,t)dt, '\IvE LZ(O,T;V),
va di@uki~n T-tu~n ho~m
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Trang 2Khao sat phuong trinh parabolic phi tuyin
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(4.6) U(O)=u(T).
Trong ph~n mlY, chung toi se chung minh bai tmln (4.1 )-(4.4) co
duy nhat mQtnghi~m y~u T-tu~n hoan va nghi~m nay cling emdinh d6i vai
I, h, uo.
4.1 S1}'tAn t~i va duy nhAt cua nghi~m y~u T-tuftn hoan
Lien quail d~n s\l't6n t~i va duy nhat nghi~m y~u T-tu~n hoan cua
bai tmln (4.1)-(4.4) ta co dinh ly sau.
Dinh If 4.1 Cho T > 0 va (H), (H~), (H~) dung Khi do, hai loan (4.1)-(4.4) co duy nhdt mr}t nghi?m yiu T-tudn hoan U E L2(0,T;V)nL"'(0,T;H), saD cho
u'EL2(0,T;H), rI/PUELP(Qr).
Chung minh Chung minh g6m nhiSu buac
Bmyc 1 PhU'O'ng phap Galerkin Ky hi~u bai {Wj},j = 1,2, la mQt cO' sa tr\l'c chu~n trong khong gian Hilbert tach duQ'CV Ta tim Urn (t) theo d~ng
(4.7)
rn
urn(t) = LCmj(t)Wj'
j=l
trong do Crnj (t), 1::;j ::;m thoa h~ phuO'ng trinh vi phan phi tuy~n
(u~ (t), Wj) + (urnr, Wjr) + h(t)urn (1,t)w/1) + (F(urn (t)), Wj)
= (/(t), Wj) + uoh(t)wj(l), 1::;j::; m,
(4.8)
va diSu ki~n T-tu~n hoan
(4.9) Urn (0) = Urn(T).
f)~u tien, ta xet h~ phuO'ng trinh (4.8) va diSu ki~n d~u
( 4.9' ) Urn(0) = UOrn'
Wj' j = 1,2, Khi do, ta thu duQ'c mQt h~ m phuO'ng trinh vi phan thuemg
H9C vien Nguyln Vii Dziing
Trang 3Khao sat phuong trinh parabolic phi tuyin
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phi tuySn v6i cac ~n ham Cmj(t),1<5,j <5,m, va cac diSu ki~n d~u (4.9') DS
th~y r~ng t6n t~i um(t) co d~ng (4.7) thoa (4.8) va ( 4.9') v6i h~u khAp nO'i
tren 0<5,t <5,Tm' v6i mQtTm' 0 < Tm<5,T Cac danh gia tien nghi~m sau day cho
phep ta l~y Tm= T v6i mQi m.
Bmyc 2 Danh gia tH~nnghi~m.
Nhan phuO'ng trinh thu j cua h~ (4.8) b6i Cmj (t), va sau do l~y tfmg theo j,
ta duQ'c
1
~llum(t)112 +21IUmr(t)112+2h(t)u;(l,t)+2 Jr2Ium(r,t)IP dr
= 2(f(t),um (t)) + 2uoh(t)um(l,t).
Tir giii thiSt (H~ ) va b~t d~ng thuc (2.9), ta suy ra r~ng
(4.11) 211umr (t)112+ 2h(t)u~ (l,t) ~ CiliUm(t)II~,
v6i CI = mill {I,ho}.
Do do, ta suy tir (4.10), (4.11) r~ng
:tllum(t)112 +CIIIUm(t)II~ +2fr2Ium(r,t)IP0 dr
<5,2(f(t),um (t)) + 2uoh(t)um(l,t)
<5, ~llf(t)112 +51IUm(t)112+ ;Iuonh[ +51IUm(t)II~
= ~llf(t)112+ ;Iuonhll: +251IUm(t)II~,'15>0
(4.12)
ChQn 5 > 0 sao cho
(4.13) CI-25=C2>0
Do do, tir (4.12), (4.13) ta thu duQ'c
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Trang 4Khao sat phuong trinh parabolic phi tuyin
trang miJn hinh cdu
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~llum dt (t)112 + C211um(t)112
I
~ ~llum(t)112+C21Ium(t)II~+2 fr2Jum(r,tW dr0
~ ;luol21lhll: + ~Ilf(t)112 = ~(t).
Nhan b~t d~ng thuc (4.14) b6i eCz! va sau do l~y tich phan theo t ta thu
(4.14)
duQ'c
!
(4.15) Ilum(t)112 ~lIuomI12e-Cz! +e-Cz! f~(s)eczsds.
0
Cho T > 0, ta xet ham s6 sau
~
{
(eel! -It f~(s)eczSds,O<t~T,
hi (0) / C2, t = O.
Khi do RE Co[O,T].Ta d~t R = max~R(t) Ta thu duQ'c tir (4.15), (4.16) r~ng o,;,!,;,r
nSu lIuomll ~ R, khi do
(4.17) Ilum(t)11~ R, i.e., Tm = T v6i mQi m.
GQi Bm(O,R)la qua c~u dong tam 0, ban kinh R trong khong gian m chiSu sinh b6i cac ham Wj' j = 1,2, ,d6i v6i chu~n 11.11.
Xet anh XI;!Fm : BJO,R) ~ BJO,R) cho b6i cong thuc
(4.18) Fm (Uom) = Um (T).
Ta se chung minh dng Fm lamQt anh XI;!co.
Giasu UOm' VOmEBJO,R) vad~t <1>m(t)=um(t)-vm(t),trongdo um(t) va vm(t)
la cac nghi~m cua h~ (4.8) tren [O,T]thoa cac diSu ki~n d~u um(O)=UOmva Vm(0) = VOm'l~n luQ't Khi do, <1> m(t) thoa h~ phuang trinh vi phan sau day
H9C vien Nguyln Vii Dziing
Trang 5Khao sat phuong trinh parabolic phi tuyin
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«D~ (t), Wj ) + «D mr(t), Wjr) + h(t)<D m (1, t)Wj (1)
=-\lum(t)1 um(t)-lvm(t)1 vm(t),Wj/' l~J~m,
va diSu ki~n d~u
(4.20) <Dm(O)= Uam-v am'
B~ng cach tinh toan gi6ng nhu 6 chuang 3, ta thu duQ'c
~II<Dm(t)llz + 211<Dmr (t)llz + 2h(t)l<D m(l,t)lz
(4.21) dt
= -2(lum (t)IP-z Um(t) -Iv m(t)IP-z Vm(t),um (t) - v m(t)) ~ 0
Nha vao (4.11), ta sur tir (4.21) r~ng
(4.22) ~11<Dm(t)llzdt +C111<Dmr(t)II~ ~ O
Tich phan b~t d~ng thuc (4.22), ta thu duQ'c
-.!.TC[
(4.23) IIUm(T)-vm(T)II~eZ IIUam-vamll,
i.e., Fm : Bm(O,R)~ BJO,R) la anh x'ilco Do do tan t'iliduy nh~t Uam E Bm(O,R)
sao cho Uam = Fm (uam) = Um (T).
Do do, v6i mQi m, tan t'ili m9t ham UamE Bm(O,R) sao cho nghi~m cua bai
toan gia trj ban d~u (4.8), (4.9') la m9t nghi~m T-tu~n hoan cua h~ (4.8) Nghi~m nay cling thoa b~t d~ng thuc (4.17) v6i h~u hSt tE [o,T] va nha
(4.14), ta sur ra
(4.24) IIUm(t)llz +Cz filum(s)lI~ds + 2 fds frzlum (r,s)IP dr ~ C3,
trong do C3 la m9t h~ng s6 d9C l~p v6i m.
M~t khac, b~ng cach nhan phuang trinh thu j cua h~ (4.8) b6i c~, l~y tlmg
theo j va sau do l~y tich phan d6i v6i biSn thai gian tir 0 dSn T, ta thu
duQ'c
H(Jc vien Nguyin Vfl Dzflng
Trang 6KhilO sat phlfO'ng trinh parabolic phi tuyin
trong miJn hinh cdu
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fllu~(t)112dt+- f-llumr(t)112dt+- fh(t)-u~(l,t)dt
T
(4.25) +0f(lum (t)IP-2 Um(t),u~ (t) }dt
= f(J(t),u~ (t))dt + Uofh(t)u~ (l,t)dt.
Tir (4.9') ta th~y r~ng
Td
f-Ilumr (t)112dt = 0,
0 dt
f(
)
= ~ fr2 ~um(r,T)IP -Ium (r,O)IP ~r = O.
Po
Do do, d~ng thuc (4.25), nha itch phan tUng ph~n, ta thu duQ'c
(4.26) fllu~(t)112dt= f(J(t),u~(t))dt+- fh'(t)-u~(l,t)dt-uofh'(t)um(I,t)dt.
Sail cling, nha VelO(4.24), (4.26), ta suy ra b~t d~ng thuc sail
2 fllu~ (t)112dt ~ fIIJ(t)112 dt +fllu~ (t)112dt +IIh'll", fu~ (I,t)dt
T
(4.27) + 21uolllh't]um(l,t)~t
0
~ fllu~ (t)1I2dt +]IJ(t)1I2dt+411h't filum (t)II~ dt
T
+41UolIlh'IL filum (t)lIvdt
0
~ fllu~ (t)1I2dt +fIlJ(t)112dt +411h't filum (t)II~ dt
+4v'Tlil, Illh'll.(~~m (')II~dtr
T
~ fllu~ (t)112 dt + C4 ,
0
Trang 7KhilO sat phuong trinh parabolic phi tuyin
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trong do C4 la ill9t h~ng s6 d9C l~p v6'i m.
V~y
T
(4.28) ~Iu~ (t)112dt ~ C4, v6'i illQi m.
0
M~t khac, tir (4.24) ta co danh gia
(4.29) Ids flr2! p'IUrn (r,s)IP-2 Urn(r,sf' dr = Ids fr21urn(r,s)IP dr ~ !C3'
BU'o-c3 Qua gio-i h~n.
Do (4.24), (4.28), (4.29) ta sur ra r~ng, tfm t<;liill9t day con cua day {uJ, v~n ky hi~u la {urn}sao cho
(4.30) Urn~ U trong LOfO(O,T;H)ySu *,
(4.31) Urn~u trong L2(0,T;V) ySu,
(4.32) u~ ~u' trong L2(0,T;H) ySu,
(4.33) r2!Purn~r2!pu trong Y(QT) ySu.
Tru6'c hSt, ta nghi~ill l<;lir~ng
(4.34) u(O) = u(T).
V 6'i illQi v E H, ta co tir (4.9) r~ng
T
(4.35) f(u~ (t), v)dt = (urn(T)- Urn (0), v) = o.
0
Ta sur tir (4.32) va (4.35) r~ng
(4.36) f(u~ (t), v)dt ~ f(u'(t), v)dt = 0, khi m~ +00,
Tinh toan tuong t\1'nhu (4.35), ta cling co d~ng thuc
T
(4.37) (u(T)-u(O),v) = f(u'(t),v)dt=O, VvEH,
0
va do do (4.34) dung.
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Trang 8KhilO sat phuong trinh parabolic phi tuyin
trang mi~n hinh c6u
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Dung b6 dS 2.11 vS tinh compact cua Lions [3], ap d\1ng vao (4.31), (4.32)
ta co thS trich ra tir day {urn} mQtday con v§,nky hi~u la {urn} sao cho
(4.38) Urn -) U m~nh trong L2(O,T;H).
Theo dinh ly Riesz-Fischer, tir (4.38) ta co thS trich ra mQt day con cua day
{urn} v§,nky hi~ula {uJ sao cho
(4.39) Urn (r,t) -) u(r,t) a.e (r,f) trong QT = (0,1)x (O,T).
Do Uf-7IUIP-2 u lien t\1C,ta co
(4 40) 21'I I
I I
P-2
r P Urn(r,f) Urn(r,f) -) r P u(r,f) u(r,f) a.e (r,f) trong QT'
Ap d\1ngb6 dS 2.12 vS S\l hQit\1ySu trong Lq(QT) v6i
II
P-2
Tir (4.29), (4.40) r~ng
(4.41) r2IP'lurnIP-2urn -)r2IP'luIP-2utrong y'(QT) ySu.
Ky hi~u g;(f) = ~ sinC:). i= 1,2, la mQt ccysa tf\lC chu~n trong khong
gian Hilbert th\lc L2(0,T) Khi do t~p {g;Wj:i, i=1,2, } cfing thanh l~p mQt ccysa tr\lc chu~n trong khong gian L2(0,T;V).
Nhan phucyng trinh thil i cua (4.8) cho g; (f), va sail do l~y tich phan d6i v6i biSn thai gian f, 0 ~ f ~ T, ta thu duQ'c
f( u~ (f), Wj ;g; (f)<if + f( urnr(f), Wjr ;g; (f)df
(4.42)
+ fh(t)urn (1, f)w/1)g; (f)df + f(lurn (f)IP-2 Urn(f), Wj )g; (f)df
= f(f(f), Wj ;g;(f)df + fuoh(f)W/1)g;(f)df, Vi = 1,2, ,m, Vi E N.
DS nghien cUu vS vi~c qua gi6i h~n cua s6 h~ng phi tuySn lurn (f)IP-2 Urn(f)
trong (4.42), ta su d\1ng b6 dS sail
H9C vien Nguyin Vfi Dzfing
Trang 9Khao sat phuong trinh parabolic phi tuyin
trong miJn hinh cdu
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BBd~4.1.
J~~oof([urn (t)IP-2 Urn(t), wi )gi(t)dt = f\lu(t)IP-2 U(t), Wi )gi(t)dt, Vi, j = 1,2,
ChungminhbBd~4.1.
Chuy r~ng (4.41)tuO'ng duO'llg v6i
fdt fr2/P'[urn(t)IP-2urn(t)<l>(r,t)dr~ f fr2/P'lu(t)la-lu(t)<l>(r,t)dt
V<l>E (U' (QT))= LP(QT).
M?t khac, ta co
f(lurn (t)IP-2 Urn(t), Wi )gi(t)dt = f fr21urn (t)IP-2Urn (t)w/r)gi(t)drdt
(
= ffr2/p'IUrn (t)IP-2Urn (t)Xr2/PWi(r)g;Ct)}irdt.
0 0
Do (4.44), b6 dS4.1 seduQ'cchUngminh nSu ta khAngdinh duQ'cr~ng
<l>(r,t)= r21 PWj (r)q:>(t) E U (QT)'Th~t v~y, do bfit dAng thuc (2.7), ta co
f f[<l>(r,t)IP drdt = f ~r2w/r)q:>(tf drdt
= fr2-P Irw/rf dr flq:>(t)IP dt
(4.45)
~ (FsIIWillvr fr2-Pdr ]q:>(tWdt
T
~ ~(Fsllwill 3 r nq:>(t)la+J dt<+00.
Cho m~ +00 trong (4.42), ta suy ra tll (4.30), (4.31), (4.32) va b6 dS 4.1,
r~ng u th6a phuO'ng trinh biSn phan
Trang 10Khao sat phuong trinh parabolic phi tuyin
trong mi~n hinh cdu
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(4.46)
f(U'(t), wi )g;Ct)dt + f(u,(t), Wi' )g;Ct)dt
+ fh(t)u(l,t)Wia (l)gj(t)dt + f(lu(t)IP-2 u(t), Wi )gj(t)dta
= f(/(t), Wi )gj(t)dt + Uafh(t)w/l)g;Ct)dt, Vi, j E N.
V~y, ta suy tu (4.46) r&ngphuang trinh sail day dung
f(u'(t), v)dt + f(u, (t), v, )dt + fh(t)u(l,t)v(l)dt
T
+ f\lu(t)IP-2 u(t), v)dta
(4.47)
= f(/(t), v(t))dt+ua fh(t)v(l,t)dt, Vv E L2 (O,T;V}
V~ys\l' t6n t~i nghi~m duQ'c chUng minh xong
Bmyc 4 Tinh duy nh~t nghi~m.
Gia su u va v la hai nghi~m ySu cua bai tmin (4.1)-(4.4) Khi do w=u-v
thoa bai toan biSn phan sail day
f(w'(t), lp(t) )dt + f[( W, (t), lp, (t)) + h(t)w(l, t)lp(1,t)}it
T
(4.48) + f(lu(t)IP-2u(t) -lv(t)IP-2vet), lp(t))dt =0,
a
Vlp E L2(0,T; V),
(4.49) w(O)= weT),
v6i u, VE L2(0, T; V)nD'(O,T;H), u', V'E L2(0, T; H), r2lpu, r21pvE H(QT}
T
L~y lp=w trong (4.48) va chu y r&ng f(w'(t),w(t))dt= o Khi do su d\lng
a (4.11) va (4.49), ta thu duQ'c
Trang 11Khao sat ph Lfang trinh parabolic phi tuyin
trong mi~n hinh cdu
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(4.50)
2C11Iw(t)II~2(o,r;v)~ fllwr ° (t)112dt +0fh(t)w2 (1, t)dt
r
= - f(lu(t)1 p-2 u(t) -lv(t)IP-2 vet), u(t) - vet) )dt ~ O.
0
DiSunay dfin dSn w= 0, i.e.,u = v Dinh ly 4.1 dugc chUngminh hoan t&t.
4.2 S1}'An dinb cua ngbi~m y~u T-tuftn boan
Trong phan ll<lYchung t6i se kh~lOsat tinh 6n dinh d6i v6i f, h, Uo cua nghi~m ySu T-tuan hoan cua bai tmin (4.1 )-(4.4).
Tuang ung v6i f, h, uo, Ian lugt thoa cac gia thiSt (H2), (H~), (H~), bai
loan (4.1)-(4.4) co duy nh&t mQt nghi~m ySu T-tuan hoan
ph\! thuQc vao u=u(f, h,uo) Ta se chung minh nghi~mnay 6n dinh d6i v6i
f, h, Uotheo illQt nghla ma ta se qui dinh sau.
Tru6c hSt ta d~t
H = {h E wi"" (O,T), h(O) = her), h(t)? ho > a},
y = {JE CO([O,T];H), f(r,O) = f(r,T)}.
Khi do, ta co dinh ly sau day lien quail dSn tinh 6n dinh cua nghi~m ySu
Binb Iy 4.2.
Nghi<?mu = u(f, h, uo) 6n dtnh dr5ivai f, h, uo, theo ngh'ia
Niu (fk,hk,uOk)' (f,h,uo)EYxHxJR, saocho
fk ~ f trong CO([O,T];H),
(4.51) hk ~h trong w1""(0,T),
UOk~ u trong JR,
thi
(4.52) Uk~u trong L2(0,T;V) va r21puk~r2lpu trong LP(Qr),
trongdo Uk =U(fk,hk,uOk)' u =u(f,h,uo).
Trang 12Khao sat phuong trinh parabolic phi tuyin
trong miJn hinh cdu
trang 39
Chung minh.
Truac hSt ta d~t them cac ky hi~u
Vk =Uk -u, Jk =fk - f, hk =hk -h, UOk=UOk-uo.
Cho v E L2(O,T;v) tllYy, tru hai d~ng thuc sau:
(4.53)
f(u~ (t), vet) )dt + f[(Ukr(t), Vr (t)) + hk (t)Uk (1, t)v(1, t)]dt + f(F(Uk (t)), vet) )dt
= f(fk (t), v(t))dt + UOkfhk (t)v(l,t)dt,
Uk(0) = Uk(T),
(4.54)
f(U'(t), vet) )dt + f[(ur (t), Vr(t)) + h(t)u(l,t)v(l, t)]dt + f(F(u(t)), vet) )dt
= f(f(t), v(t))dt+UOk fh(t)v(l,t)dt,
U(O) = u(T),
ta thu duQ'c
(4.55)
f(v~ (t), vet) )dt + f[( Vkr(t), Vr (t)) + (hk (t)Uk (l,t) - h(t)u(l, t) )v(1, t)]dt
T + f(F(Uk(t))-F(u(t)),v(t))dt
0
=f((Jk(t)}v(t))dt+ f(UOkhk(t)-uoh(t))v(1,t)dt.
Ch<;>nv = Vk' trong (4.55) va sau khi chu y r~ng
(4.56) f((v~(t)), Vk(t))dt = - f-lIvk (t)lldt= -llvk (T)II llvk (0)11= 0,
ta thu duQ'c
Trang 13Khao sat phuang trinh parabolic phi tuyin
trong mi~n hinh cdu
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(4.57)
fllvkr (t)112dt + f(hk (t)Uk (l,t) - h(t)U(l,t))vk (l,t)dt
T + f(F(Uk (t))- F(u(t)), Vk(t))dt
0
= f(Jk (t), Vk(t) }dt + f(UOkhk(t) - uOh(t))vk (l,t)dt,
hay
flhr (t)112dt + f hk (t)vi (l,t)dt + fhk (t)u(l,t)vk (l,t)dt
T
+ f(F(Uk (t))-F(u(t)),Vk (t))dt
0
= f(Vk (t)) Vk (t) }dt + UOkfhk (t)Vk (l,t)dt
T +uo fhk(t)vk(l,t))dt.
0
Chu y r&ng
(4.59) ]IVkr(t)112dt + fhk (t)vi (l,t)dt ~ C) ]h(t)II~dt = c)llvkll~2(O,T;V)'
trong d6 C) = mill{1,ho} Dung bfit d~ng thuc
(4.60) '\Ip~2, 3Cp >O:~XIP-2X-lxIP-2XXX-y)~cplx-yIP '\Ix, yeIR,
ta suy ra
(4.61) f(F(Uk (t))- F(u(t)), Vk(t))dt ~ Cp fdt fr21uk (t) - u(t)IP dr =Cp IIr2/ PVk II;p(Qr)'
B&ng each sir d\lng bfit d~ng thuc (4.60), ta suy ra tll (4.58)-(4.61) r&ng
c)llvkll~2(O,T;V) +Cpllr2/Pvkll;p(Qr)
(4.62)
~ - fhk (t)u(l, t)v k (1, t)dt + f\Jk (t), Vk (t) }dt
+UOkfhk (t)Vk (l,t)dt + Uo fhk(t)Vk (l,t)dt
H9C vien Nguyln Vii Dzilng
Trang 14Khao sat phuong trinh parabolic phi tuyin
trong miJn hinh cdu
trang 41
S 411hkt fllu(t)llv Ilvk(t)llv dt + Illkllco([O,T];H) fllvk (t)llv dt
+ 21uOk Illhk t ~h (t)llv dt + 211hk t Iuol fllvk (t)IIv dt
S 411hk IIJuIIL2(O,T;V) Ilvk IIL2(O,T;V)+ Illk Ilco([o,T];H)Frllvk t2(O,T;V) + 21uOk Illhk t Frllvk t2(O,T;V) + 211hk t IUDIFrllvk IIL2(O,T;V)
=[2(21Iut2(O'T;V)+ Frluolllhkt + Frlllkllco([O,T];H)+2FrllhkIUuOkl]lvkt2(O,T;V)
== 8k IIVkt2(O,T;V)'
tfong do
(4.63) 8k =2(21IuIIL2(O'T;V) + Frluol)llhkt + Frlllkllco([O,T];H)+2FrllhktluOkl.
Ta Suy fa tu (4.62) dng
1 (4.64) Ilvk(t)112( .
) S-8k'
L O,T,V C)
II
21
li
(4.65) c)llvkIIL2(O,T;V)+Cpr PVkLP(QT)SC) k'
11
21p
21pV
II
(4.67) Ih L2(O,T;V) + r k LP(QT)- C) ~C)Cp
Tu gia thiSt (4.51), ta co
Il hkII ~ 0,
00 CO([O,T];H)
va day s6 ~Ihk t } bi ch~n, nen 8k ~ O.
V~y
I II II
21pV
IVk L2(O,T;V) + r k LP(QT) - c) ~C)Cp
Dinh ly 4.2 duQ'c chung minh hoan t~t