I am trying to find heat transferred from outer cylinder to inner cylinder.
Cylinders are concentric.

For this I need view factor for two concentric cylinders with following dimensions:


For outer cylinder:

L1=length,H1=height,R1=radius

and, for inner cylinder

L2=length,H2=height,R2=radius

and

L1>L2,H1>H2,R1>R2


All these 6 numbers are FINITE. Particularly, lengths are NOT infinite; i.e. cylinders are NOT very long.

Since I am not from engineering background, I would appreciate if someone write general expression for view factor in terms of above 6 numbers.