Thermal Conductance Value (Approriate Modeling?)
Thermal Conductance Value (Approriate Modeling?)
(OP)
Hi all,
I am modeling two aluminum plates (.125 in thick, 1.048 in tall,2.25 in long) connected at a right angle to each other along the short side. There are three fasteners spaced evenly (NAS 662 Flat Head Screws (100°)). I take the thermal resistance to be L/kA with its inverse being the thermal conductance. For L I use the thickness of the plate (.125"). However, the units of this formulation are (m)/((W/m/K)(m^2)) giving W/K. ANSYS requires thermal conductance in W/m^2/K. So if I leave out the Area, the units are correct but then it seems that ANSYS is always using a Wet Interface (i.e. all the area around the bolts) but I want to represent a lesser area (a circle around each bolt whose diameter is 2*bolt diameter). Any advice is appreciated.
I am modeling two aluminum plates (.125 in thick, 1.048 in tall,2.25 in long) connected at a right angle to each other along the short side. There are three fasteners spaced evenly (NAS 662 Flat Head Screws (100°)). I take the thermal resistance to be L/kA with its inverse being the thermal conductance. For L I use the thickness of the plate (.125"). However, the units of this formulation are (m)/((W/m/K)(m^2)) giving W/K. ANSYS requires thermal conductance in W/m^2/K. So if I leave out the Area, the units are correct but then it seems that ANSYS is always using a Wet Interface (i.e. all the area around the bolts) but I want to represent a lesser area (a circle around each bolt whose diameter is 2*bolt diameter). Any advice is appreciated.





RE: Thermal Conductance Value (Approriate Modeling?)
a) Scale your thermal conductance values to give you the desired result at the respective interfaces (ie. you may have to define more than one real constant set to apply to your contact elements). Or if you're using Ansys WB this is super easy.
b) Create custom contact or custom contact components so you have complete control over where conduction can and cannot occur.
-Brian
RE: Thermal Conductance Value (Approriate Modeling?)