, - . - . : 2/2=(1/c)×/t +q (1)
c=k×K/(mm)
:
=/L; =P/P; q=c×t/L2; (2)
x= ×L;= ×P; t=q×L2/c; (3)
(3) (1):
2/2= (( ×P)/x)=(P/L2)* 2 / 2 (4)
/t=(c×P/L2)× /q (5)
(/L2)×2 / 2=(c×/c×L2) /q+ ×f/L2; f=q×L2/P; q=P×f/L2. (6)
2 / 2= /q+f (7).
, , .
2/2=/q+f (7')
:
()=()+'()(-)+''()(-)2/2!+(8)
i, i. i+1 i-1
i+1=Pi+Pi'Dx+Pi''(Dx)2/2!+Pi'''(Dx)3/3!+ (9)
i-1=Pi-Pi'Dx+Pi''(Dx)2/2!-Pi'''(Dx)3/3!+ (10). (9) :
i'=(i+1-i)/Dx-Pi''×Dx/2!+Pi'''×(Dx)2/3!- (11)
i'=(i+1-i)/Dx-0(Dx) (12)
0(Dx) Dx. (10)-:
i'=(i-i-1)/Dx+0(Dx) (13)
(12) (13):
i'=(i+1-i-1)/(2×Dx)+0(Dx)2 (14)
0(Dx)2 - Dx.
(9) (10):
i+1+ i-1=2i+2 Pi''(Dx)2/2!+4 PiIV(Dx)4/4!+ (15)
i''=(i-1-2×i+i+1)/(Dx)2+0(Dx)2 (16)
Dt= τ. k .
P/q k'= (Pk-Pk-1)/t+0(t); Dq=t (17) - .
(-1)- (-1).
(n-1) 2 0 n. (16) (-1) :
(i-1,k-1-2×Pi,k-1+Pi+1,k-1)/(Dx)2=(Pi,k-Pi,k-1) / t + fi,k (18) - .
: i-1,k-1; i,k-1; i+1,k-1. fi,k () .
(18) - , Pi,k. (18) k- :
(i-1,k-2×Pi,k+Pi+1,k)/(Dx)2=(Pi,k-Pi,k-1)/t+fi,k (19) - - , - (n-1)+2=n+1 n+1 . (19) 3 .
- (19) n+1 - n+1 . .
t£(D)2/2 - . .
7 (35) - (
(Pi-1,k-1- 2Pi,k-1+ Pi+1,k-1)/(∆x)2=(Pi,k- Pi,k-1)/τ+fi,k, (1), (Pi-1,k-1, Pi,k-1, Pi+1,k-1-) - - .
|
|
(Pi-1,k- 2Pi,k+ Pi+1,k)/(∆x)2= (Pi,k- Pi,k-1)/ τ+fi,k, (2)- , i=1,n-1.
- , (n+1) - (n+1) - . (i=0,i=n) . , :
) (i=0): / (3)
(1,-0,)/∆=0 (4)- (3);
) (i=n): / (5)
n,-(n-1),)/∆=0(6)-- (5).
(4) 0,= 1, (4). (6) (n-1),= n, (6). , . - . -.
i=1:(P2,k- 2P1,k+ P0,k)/(∆x)2= (P1,k- P1,k-1)/τ+f1,k (7). (4) : (P2,k- P1,k)/(∆x)2= (P1,k- P1,k-1)/τ+f1,k (8)
1,=[2,+(∆x)2(P1,k-1- τ f1,k)/τ ] / [1 + (∆x)2/τ] (9)
:1,=1/(1+(∆x)2/τ); 1,=((∆x)2/τ)/(1+(∆x)2/τ))*(1,-1-τ*f1,) (10).
1,=1,2,+1, (11).
:
i=2: 2,=2,3,+2, (12).
2,=1/(2-1,+(∆x)2/τ),,.(29)
2,={1,+(∆x)2 *(2,-1-τ*f2,) /τ }/(2- 1,+(∆x)2/τ) (13).
i: i,=i,(i+1),+i, (14).
i,=1/(2-i-1,+(∆x)2/τ),,.(31)
i,={i-1,+(∆x)2 *(i,-1-τ*fi,) /τ }/(2- i-1,+(∆x)2/τ) (15).
i=n-1: n-1,=n-1,n,+n-1, (16).
(6) : n-1,= n-1, /(1-n-1,) (17).
- . -. . - i ( ). - i, .. . . f1,k=0. f1,k> <0 , .
8. - - . - - - - . - - - .
-:
1. .
2. - - .
3. - .
4. - .
5. -.
- , - - , .. - . - - - .
- . - - , - :
|
|
q1/(αW1)=q2/(αW2)==qn/(αWn) (1)
qi - i- -; αWi- i- -. (1) - - - -.
- - - . - -. - - , . , - - - - ( ).
- - - -. : ; - ; -; ; ; . : - ; . .
- , - . - - - .
- - - .
- P, -, - - -. .
-, , . - . -, .
- - (, ). - - ( -, 50-70 ), / 1,5 .
-. -. - - .
, - - - .