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:


and, for inner cylinder




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.