A grommet assembly and method of design to enhance the flow coefficient, thereof, includes a shell having a first side and an opposite second side, and a chamfered grommet projecting through the shell along a centerline and including an annular first end surface spaced outward from the first side and a conical face spanning axially and radially inward from the annular first end surface and axially beyond the second side. The assembly may further include a panel spaced from the shell and defining a cooling cavity therebetween with the conical surface defining at least in-part a hole in fluid communication through the shell and panel and isolated from the cooling cavity. A plurality of cooling channels in the grommet are in fluid communication with the cooling cavity and communicate through the panel. The combination of the conical face and the cooling channels improve the discharge coefficient of the grommet while enhancing grommet cooling.