Question-and-Answer Resource for the Building Energy Modeling Community
 | 1 | initial version |
One thing you could do is use therm to model the curvature in small segements (to get the area close to right) and then do runs using standard vertical wall convection coefficients for the whole surface and the other using a convection coefficient appropriate for the largest angle. You can find convection coefficients for angled planes in the ASHRAE handbook of fundamentals in the heat transfer section.
Then you can get a bound on the U value you would have if you used software that computes true convection. If they end up being close, you might want to use the average of the two as your estimate. if they differ wildly (meaning that convection effects dominated heat transfer) then you know you probably need to go to a more complete heat transfer program like Fluent or Comsol Multiphysics. You might still use the average as a guess.
