Abstract: A centrifugal fluid machine includes an impeller (4) that has a front shroud (41) arranged on one side in an axial direction, a rear shroud (42) arranged on the other side in the axial direction, and a plurality of blades (43) provided side by side in a circumferential direction between the front shroud and the rear shroud and is rotatably supported within a casing (2); a suction passage (2A) that allows a fluid to be sucked therethrough in the axial direction toward the impeller with the rotation of the impeller; a discharge passage (2B) that allows a fluid delivered under pressure by the impeller with the rotation of the impeller to be discharged in a direction intersecting the axial direction of the impeller; and a first flow path (5A) that communicates with the discharge passage, leads to the suction passage through a gap between the casing and the rear shroud, and an opening (5Aa) that opens toward the downstream side of the suction passage in a suction direction of a fluid.

Abstract: A centrifugal fluid machine includes an impeller (4) that has a front shroud (41) arranged on one side in an axial direction, a rear shroud (42) arranged on the other side in the axial direction, and a plurality of blades (43) provided side by side in a circumferential direction between the front shroud and the rear shroud and is rotatably supported within a casing (2); a suction passage (2A) that allows a fluid to be sucked therethrough in the axial direction toward the impeller with the rotation of the impeller; a discharge passage (2B) that allows a fluid delivered under pressure by the impeller with the rotation of the impeller to be discharged in a direction intersecting the axial direction of the impeller; and a first flow path (5A) that communicates with the discharge passage, leads to the suction passage through a gap between the casing and the rear shroud, and an opening (5Aa) that opens toward the downstream side of the suction passage in a suction direction of a fluid.

Abstract: A rocket nozzle includes a dual-bell nozzle and a gas introducing section configured to introduce gas into space surrounded by the dual-bell nozzle. Combustion gas flows in the space. The dual-bell nozzle includes a first stage nozzle bell-shaped and surrounding an upstream portion of the space, and a second stage nozzle bell-shaped and surrounding a downstream portion of the space. The dual-bell nozzle has an inflection point between the first stage nozzle and the second stage nozzle. The gas introducing section includes a gas inlet provided to an inner wall surface of the first stage nozzle. The gas is introduced into the space from the gas inlet.

Abstract: A rocket nozzle includes a dual-bell nozzle and a gas introducing section configured to introduce gas into space surrounded by the dual-bell nozzle. Combustion gas flows in the space. The dual-bell nozzle includes a first stage nozzle bell-shaped and surrounding an upstream portion of the space, and a second stage nozzle bell-shaped and surrounding a downstream portion of the space. The dual-bell nozzle has an inflection point between the first stage nozzle and the second stage nozzle. The gas introducing section includes a gas inlet provided to an inner wall surface of the first stage nozzle. The gas is introduced into the space from the gas inlet.