Airfoil cooling holes

A gas turbine engine comprising:

• a compressor section;
• and
• a turbine section;
• wherein at least one of the compressor section and the turbine section comprise an airfoil having an airfoil wall having an inner wall surface and an outer wall surface;
• and
• a cooling hole formed within the airfoil wall having an inlet formed in the inner wall surface and an outlet formed in the outer wall surface, wherein the cooling hole defines a fluid path through the airfoil wall from the inlet to the outlet, wherein the cooling hole has a metering section extending from the inlet to a transition point and a diffusing section extending from the transition point to the outlet,
• wherein the metering section is defined by a uniform geometry,
• wherein the diffusing section is defined by a lobed portion that extends from the transition point toward the outlet, the lobed portion having a first lobe and a second lobe divided by a ridge surface,
• wherein each lobe defines continuous curved surfaces along the length of the ridge surface.