How inject gas in air medium???
 

I want to analysis the super critical airfoil,I created the 2D mesh for that, & want to inject the inert gas on the particular point in the upper surface of airfoil during air airflow over the airfoil,& I want to know what are the changes accruing in air medium;I don't know how i can inject & found the changes accruing on airfoil;can anyone suggest how can I proceed to succeed that:confused::confused::confused: