surface integrated mass flux at inlet and outlet

Hi all,

I was evaluating the surface integrated mass flux at the inlet and outlet of my model. 

In the inlet section, the values of surface integrated mass flux is negative:-

But, in the outlet section, its value is positive:-

From the thermodynamics point of view, mass transfer to the system is positive while mass transfer from the system to the surrounding is negative.

The same goes to the surface integrated heat flux.

Can someone explain why is this different in acusolve?

Thanks and regards,