[behnamEll]

Hello every one,
I need to make a "unit phi" to get the div(phi,U)/mag(phi).
but in this case, the 1/mag(phi) may lead to a core dumped (floating point exception) error.

in fact, i try to make a surfaceScalar/volScalar/volVector such that:
-------------------------------------------------------

if ( mag(surfaceScalar) == 0 )
surfaceScalar = 0;
else
surfaceScalar/mag(surfaceScalar);
-------------------------------------------------------



can anyone help me?

[SHUBHAM9595]

I'm not sure what you want to achieve with "unit phi".

But to avoid FPE you can just simply add the machine epsilon in the denominator. Something like

surfaceScalarField your_Desired_var = 1/(mag(phi) + VSMALL);

where VSMALL is float having magnitude 1.93e-34

[behnamEll]

in fact i am looking for a property on the cell face using *upwind* schemes, but without the phi magnitude.

for example .(mdot U) without the mdot magnitude.

by adding an small values, again, there is a possibility that the values ​​will be zero. because there are negative and positive values ​​of it.

[olesen]

Originally Posted by behnamEll

Hello every one,
I need to make a "unit phi" to get the div(phi,U)/mag(phi).
but in this case, the 1/mag(phi) may lead to a core dumped (floating point exception) error.

in fact, i try to make a surfaceScalar/volScalar/volVector such that:
-------------------------------------------------------

if ( mag(surfaceScalar) == 0 )
surfaceScalar = 0;
else
surfaceScalar/mag(surfaceScalar);
-------------------------------------------------------

can anyone help me?

stabilise() ? Eg, x / stabilise(y, SMALL)