COMBUSTOR AND GAS TURBINE

A combustor equipped with a combustion cylinder and an acoustic liner that is provided on the outside of the combustion cylinder, with a space formed between the outer circumferential surface of the combustion cylinder and the liner. A group of through-holes is formed in the combustion cylinder, and the group of through-holes is formed by arranging in the axial direction, with intervals therebetween, multiple rows of through-holes which are arranged in the circumferential direction with intervals therebetween. The through-holes in each row of through-holes are arranged so as to overlap, in the circumferential direction, the through-holes in the adjacent rows, with the central axes of the through-holes offset in the circumferential direction with respect to the central axes of the through-holes in the adjacent rows. Cooling grooves are formed, so as to avoid the aforementioned through-holes, in the interior which is between the outer circumferential surface and the inner circumferential surface of the combustion cylinder and which corresponds to the location where the acoustic liner is attached. The cooling grooves include horizontal cooling grooves that extend in the circumferential direction between the rows of through-holes and vertical cooling grooves that extend in the axial direction between the through-holes and connect the adjacent horizontal cooling grooves.