摘要 |
Provided is a rotating fluid machine capable of holding down a decrease rate of a circumferential velocity of a leakage fluid in an interspatial flow passage and thereby controlling an unstable fluid force. A steam turbine includes: an interspatial flow passage 15 formed between an outer circumferential surface of a rotor blade cover 6 and an inner circumferential surface of a grooved section 14 in a casing 1; annular sealing fins 17A to 17D spatially arranged in a direction of a rotor axis, at a side of the rotor blade cover 6 in the interspatial flow passage 15; and a friction enhancement portion (more specifically, rough surfaces 19A to 19E) disposed over the whole circumference on the side of the rotor blade cover 6 in the interspatial flow passage 15. |