Abstract: An ejector device includes a nozzle having an inner wall surface defining a circular cross-sectional fluid passage extending from an inlet to a jet port. Furthermore, the fluid passage has a throat portion at a position between the inlet and the jet port, and a passage expanding portion in which the cross-sectional area of the fluid passage is enlarged from the throat portion as toward downstream. The passage expanding portion includes a middle portion in which the inner wall surface is expanded in a fluid flow direction by a first expanding angle, and an outlet portion from a downstream end of the middle portion to the jet port, in which the inner wall surface is expanded in the fluid flow direction by a second expanding angle that is larger than the first expanding angle. The ejector device can be suitably used for a refrigeration cycle apparatus.

Abstract: An ejector includes a nozzle for decompressing a fluid in any one state of a gas-liquid state, a liquid state and a super-critical state, and a body portion having a fluid suction port and a mixing and pressurizing portion. The ejector is provided with a suction passage through which a fluid drawn from the fluid suction port flows into the mixing and pressurizing portion. The suction passage is changed such that the fluid drawn from the fluid suction port is decompressed in the suction passage in iso-entropy. Alternatively, the suction passage is changed such that a flow velocity of the fluid flowing into the mixing and pressurizing portion from the suction passage is substantially equal to a flow velocity of the fluid flowing from a jet port of the nozzle into the mixing and pressurizing portion, or is equal to or larger than the sound velocity.

Abstract: An ejector device includes a nozzle having an inner wall surface defining a circular cross-sectional fluid passage extending from an inlet to a jet port. Furthermore, the fluid passage has a throat portion at a position between the inlet and the jet port, and a passage expanding portion in which the cross-sectional area of the fluid passage is enlarged from the throat portion as toward downstream. The passage expanding portion includes a middle portion in which the inner wall surface is expanded in a fluid flow direction by a first expanding angle, and an outlet portion from a downstream end of the middle portion to the jet port, in which the inner wall surface is expanded in the fluid flow direction by a second expanding angle that is larger than the first expanding angle. The ejector device can be suitably used for a refrigeration cycle apparatus.