Уравнения математической физики. Мицик М.Ф. - 20 стр.

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 (77)  (78):
( ) ( )
( )
dt
rtrrr
rr
tfru
2
0
2
0
22
0
cos22
1
;
+
=
ϕπ
ϕ
π
π
(79)
. , 
( )
ϕf
, 
( ) ( )
ϕϕ fru ;
, 
0
rr
.
( )
ϕ;ru
.

, .
, 
:
HzzRrRr ==== ,0,,
21
:
( ) ( )
( ) ( )
,0
;;
,0
0;;
;;,;;
2211
=
=
==
z
Hru
z
ru
uzRuuzRu
ϕϕ
ϕϕ
(80)

21
,uu
.
 5.
.
.
0
2
2
2
2
2
2
=
+
+
z
u
y
u
x
u
O
H
1
R
2
R
X
Y
D
                                                                      (77)                     (78):
                              π
                                                    r02 − r 2
            u (r; ϕ ) =       ∫−π f (t ) r02 − 2r0 r cos(t − ϕ ) + r 2 dt
                         1
                                                                                                       (79)
                        2π
                                                             .                             ,
f (ϕ ) −                                  ,       u (r ; ϕ ) → f (ϕ ) ,              r → r0    . u (r ; ϕ )
                                                                                           .

                                                                             –
                                      ,                                                .

                                                                         ,
                                                                  :
            r = R1 , r = R2 , z = 0, z = H
                                                                                 :
            u (R1 ; ϕ ; z ) = u1 , u (R2 ; ϕ ; z ) = u 2
             ∂u (r ; ϕ ;0)      ∂u (r ; ϕ ; H )                                                        (80)
                           = 0,                 = 0,
                 ∂z                  ∂z
      u1 ,u 2 −                   .
                                                    Z

                                              H




                                              O                  R1
                          D
                                                                                           Y
                               R2
                      X
                                                        5.

                                                             .
                                                                  .
                    ∂ 2u ∂ 2u ∂ 2u
                        +    +     =0
                    ∂ x2 ∂ y2 ∂ z2