NDSolve WärmeDGL und Randwerte

[klamser <klamser@XXXXXXX.de>]

Hallo

bei (Aufheizen eines Zylinders aus Sand von unten)


Needs["VectorAnalysis`"]
SetCoordinates[Cylindrical[r,\[Alpha],z]]
CoordinateRanges[]
c\[Rho]Sand=1.3 J/(cm^3 K) ((100 cm)/(1 m))^3 1/(J/(K m^3));
\[Lambda]Sand=0.33 W/(m K) 1/(W/(K m));
R=1;H=2;RI=R/3;
Randbedingungen={(T^(0,0,0,1))[r,\[Alpha],z,t]==0,(T^(0,2,0,0))[r,\[Alpha],z,t]==0,(T^(1,0,0,0))[r,\[Alpha],z,t]==0,(T^(0,0,2,0))[r,\[Alpha],z,t]==0,(T^(2,0,0,0))[r,\[Alpha],z,t]==0}/.t->0;
(PDEWäermeleitung=D[T[r,\[Alpha],z,t],{t,1}] c\[Rho]Sand==\[Lambda]Sand 
Div[Grad[T[r,\[Alpha],z,t]]]//FullSimplify);
PDGL=Join[{PDEWäermeleitung,T[0,0,0,0]==T[r,0,0,0]==T[0,\[Alpha],0,0]==T[r,\[Alpha],0,0]==273+175,T[r,\[Alpha],H,0]==273+65,T[R,\[Alpha],z,0]==273+60,T[r,\[Alpha],z,0]==273+20},Randbedingungen];
R=1;H=2;RI=R/3;
NDSolve[PDGL,T,{r,0,R},{\[Alpha],-\[Pi],\[Pi]},{z,0,H},{t,0,100}]
1.3`*^6 (T^(0,0,0,1))[r,\[Alpha],z,t]==(0.33` (r 
(T^(0,0,2,0))[r,\[Alpha],z,t]+(T^(0,2,0,0))[r,\[Alpha],z,t]/r+(T^(1,0,0,0))[r,\[Alpha],z,t]+r 
(T^(2,0,0,0))[r,\[Alpha],z,t]))/r

erhalte ich immer die Fehlermeldung, dass

NDSolve::bcedge: ... is not specified on a single edge of the boundary 
of the computational domain.

Habe versucht Randwerte für alle Ecken zu definieren.

Danke,

Peter