Combined structure air film hole for cooling front edge of turbine blade

The invention discloses a combined structure air film hole for cooling the front edge of a turbine blade. The air film hole comprises a first through hole and a conical hole which are communicated in sequence from the inlet direction to the outlet direction, the first through hole and the conical hole are arranged in a non-coaxial manner, and the cross section area of an outlet of the conical hole is larger than the area of the cross section of the first through hole; the axis of the first through hole is a straight line; and the inner wall surface of the first through hole and the inner wall surface of the conical hole have no corner angles. According to the combined structure air film hole, a well cooling air film can be formed at the front edge of the blade, the first through hole controls the flow of cooling air, the conical hole increases the outlet area of the air film hole, the speed of cooling air at the outlet of the air film hole is reduced, the covering effect of cooling air flow is improved, the c