[SJSW]

Hi~

I found F_AREA in ANSYS Help.
It's F_AREA(A,f,t) with A[ND_ND], face_t f, and Thread *t.
A is a vector.

However, I didn't find F_AREA_CACHE in ANSYS Help.
I found it on the internet, but I don't know the differences between F_AREA and F_AREA_CACHE.

The example use for F_AREA is as follows:
real A[ND_ND], area;
real area;
F_AREA(A, f, t);
area = NV_MAG(A);

The example use for F_AREA_CACHE is as follows:
area = NV_MAG (F_AREA_CACHE (f, t));

It seems that they are the same?
What are the differences?
Thank you!

[pakk]

In Fluent 17.1, metric.h contains the following line:

#define F_AREA(A,f,t)NV_V(A, =, F_AREA_CACHE(f,t))

This means that every time that your write

F_AREA(A,f,t);
area=NV_MAG(A);

this is fully identical to

NV_V(A, =, F_AREA_CACHE(f,t));
area=NV_MAG(A);

which is functionally identical to (assuming you don't use A later on)

area=NV_MAG(F_AREA_CACHE(f,t));

But the Fluent manual only talks about F_AREA. So it is best to use F_AREA, as it is possible that in later version they change the code in the background, and then F_AREA_CACHE might no longer work (or even worse: it works but gives a different result).