Turbine blade and gas turbine

1. A turbine blade comprising:

an airfoil;

a supply channel extending through the interior of the airfoil in the span direction, through which cooling fluid flows;

a pin fin channel extending from the supply channel along the center line of the airfoil toward the trailing edge of the airfoil and opening at the trailing edge to the exterior of the airfoil;

a plurality of gap pin fins projecting from a pair of opposing inner walls that constitute the pin fin channel at a region at the supply channel side of, the pin fin channel and forming a gap between ends of the gap pin fins such that the ends are not in contact with each other, said gap extending in the span direction;

pin fins connecting the pair of opposing inner walls at a region at the trailing edge side of the pin fin channel; and

an insertion portion disposed in the gap to decrease the area of the channel of the cooling fluid at the region at the supply channel side of the pin fin channel.

2. The turbine blade according to claim 1 , wherein the cross-sectional area of the insertion portion decreases from the supply channel toward the trailing edge.

3. The turbine blade according to claim 1 , wherein the ends of the gap pin fins and the insertion portion are in contact.

4. A gas turbine comprising the turbine blade according to claim 1 .