Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
Is the curved curtain wall you're describing something like the one at Sea-Tac? 
In which case, couldn't you model a planar window with the window U-value adjusted by the ratio of the curved area to the planar area? Assuming the opening for solar radiation is the same, and neglecting any complex convective or solar transmission effects.
