US 2010068068 A1 abstract a cooling system for a turbine airfoil of a turbine engine having at least one diffusion film cooling hole positioned in an outer wall defining the turbine airfoil is disclosed the diffusion film cooling hole includes first and second sections the first section may function as a metering section and the second section may function as a diffusion section the second section may include flow restriction ribs that direct the flow of cooling fluids in disproportionately larger amounts proximate to the downstream side of the diffusion film cooling hole application_number US 33833108 A description as shown in fig3 8 this invention is directed to a turbine airfoil cooling system 10 for a turbine airfoil 12 used in turbine engines in particular the turbine airfoil cooling system 10 is directed to a cooling system 10 having an internal cavity 14 as shown in fig4 positioned between outer walls 16 forming a housing 18 of the turbine airfoil 12 the cooling system 10 may include a diffusion film cooling hole 20 in the outer wall 16 that may be adapted to receive cooling fluids from the internal cavity 14 meter the flow of cooling fluids through the diffusion film cooling hole 20 and release the cooling fluids into a film cooling layer proximate.