Hello,

Can any one tell me what does AREA WEIGHTED AVERAGE mean? And how does Fluent calculate the values under Surface integrals -> total surace heat flux and surface heat tranfer coefficient.

Thank You in advance.

Area weighted average (AVA):

------------------------------
| _______ |
| \ V1 / ----- |
| \ / / \ | <--- Region of Interest
| \ / / V2 \ |
| --------- |
------------------------------

AVA = [(V1 * Area of inverted triangle) + (V2 * Area of Trapezium)] / [Area of inverted triangle + Area of Trapezium]

Where 'V' can be any value such as velocity, volume fraction etc. Point in the above figure being that V1 is chosen to represent the triangle completely just as V2 is chosen to entirely represent the trapezium!

Your Arithmatic mean for the Area averaged value [ (V1 + V2) /2 ] is a special case of the above (when the areas of the triangle and trapezium are equal.

Fluent calculates the AVA using [ (area of the face times the value at the face center) / (total face area) ]. This is done for whatever boundary/iso-surface you have selected.