https://forums.autodesk.com/t5/cfd-forum/cfd-convection-simulation-for-building-with-open-sides/m-p/13765388#M26836 <P>Hi,</P><P>I am an absolute novice at CFD, but I have set myself a task for an engineering project to determine the convection within a building with open sides. I have set radiation on and set the location for the sun and an initial midday time for summer solstice 21/12/25 (southern hemisphere). I wondering how I set the exterior walls as open to the environment. Effectively the building is a hybrid agricultural structure with the lower level an animal shelter as a composting barn, topped with a greenhouse for hydroponics. I just want to establish a baseline of the effects on the building before adding complicating factors such as compost generating heat , 660 cows.</P><P>I have also been looking at this in Ansys Fluent, which has a setting of ambient for the external surfaces but Autodesk CFD doesn't, what should I do for these walls. I used Autodesk CFD some 10 years ago just playing with heat in room generated by a log burner, so have a little more familiarity with its interface than I do with Fluent.</P><P>I did get one solve which didn't make sense temperature wise, generated a report (attached), CFD file also attached and snip of temp ortho image.</P><P>&nbsp;</P><P>any help gratefully recieved</P><P>Malcolm (ps didn't like my cfz file so not attached)</P> Wed, 13 Aug 2025 08:30:19 GMT mjs0757 2025-08-13T08:30:19Z https://forums.autodesk.com/t5/cfd-forum/cfd-convection-simulation-for-building-with-open-sides/m-p/13765388#M26836 <P>Hi,</P><P>I am an absolute novice at CFD, but I have set myself a task for an engineering project to determine the convection within a building with open sides. I have set radiation on and set the location for the sun and an initial midday time for summer solstice 21/12/25 (southern hemisphere). I wondering how I set the exterior walls as open to the environment. Effectively the building is a hybrid agricultural structure with the lower level an animal shelter as a composting barn, topped with a greenhouse for hydroponics. I just want to establish a baseline of the effects on the building before adding complicating factors such as compost generating heat , 660 cows.</P><P>I have also been looking at this in Ansys Fluent, which has a setting of ambient for the external surfaces but Autodesk CFD doesn't, what should I do for these walls. I used Autodesk CFD some 10 years ago just playing with heat in room generated by a log burner, so have a little more familiarity with its interface than I do with Fluent.</P><P>I did get one solve which didn't make sense temperature wise, generated a report (attached), CFD file also attached and snip of temp ortho image.</P><P>&nbsp;</P><P>any help gratefully recieved</P><P>Malcolm (ps didn't like my cfz file so not attached)</P> Wed, 13 Aug 2025 08:30:19 GMT https://forums.autodesk.com/t5/cfd-forum/cfd-convection-simulation-for-building-with-open-sides/m-p/13765388#M26836 mjs0757 2025-08-13T08:30:19Z