Abstract: A NOF-based read control method, apparatus, and system belong to the field of networked storage. The method includes: receiving, by a NOF engine by using a communication link, a read request sent by a host; sending at least one read command to an NVMe hard disk based on the read request; and when congestion occurs on the communication link, generating a congestion flag corresponding to the communication link, and sending the congestion flag to the NVMe hard disk, where the congestion flag is used to instruct the NVMe hard disk to suspend processing of the read command corresponding to the communication link.

Abstract: A NOF-based read control method, apparatus, and system belong to the field of networked storage. The method includes: receiving, by a NOF engine by using a communication link, a read request sent by a host; sending at least one read command to an NVMe hard disk based on the read request; and when congestion occurs on the communication link, generating a congestion flag corresponding to the communication link, and sending the congestion flag to the NVMe hard disk, where the congestion flag is used to instruct the NVMe hard disk to suspend processing of the read command corresponding to the communication link.

Abstract: A centrifugal compressor includes an asymmetric self-recirculating casing treatment that includes, on an inner face of a casing 10, a suction ring groove 1, a ring guide channel 2 and a back-flow ring groove 3 to form a self-recirculating channel. An axial distance Sr from an upstream end face of the suction ring groove 1 to an impeller full blade leading edge 4 or a width br of the suction ring groove 1 is represented as A·sin(?+?0)+A0 and is distributed in a sinusoidal shape in a circumferential direction, an initial phase angle ?0 is in a range of 0°??0?360°, and a circumferential angle ? of the casing 10 has a definition range of ?0????0+360°. In the expression, A denotes amplitude of distribution of the axial distance Sr or the width br, and A0 denotes an average of the axial distance Sr or the width br.

Abstract: A centrifugal compressor has a casing 7. In the casing 7 is formed a back-flow channel 9 to return fluid from a downstream position of an impeller full blade leading edge 6a to an upstream position of the impeller full blade leading edge 6a. The back-flow channel 9 includes a suction ring groove 9a and a back-flow ring groove 9b. The suction ring groove opens at the downstream position on the inner face 7a of the casing 7, and extends in the circumferential direction. The back-flow ring groove opens at the upstream position on the inner face 7a, and extends in the circumferential direction. Distribution in the circumferential direction of the axial-direction position of the suction ring groove 9a or a width of the suction ring groove 9a is asymmetric with reference to the rotation axis.

Abstract: A centrifugal compressor includes: a volute casing including a first casing and a second casing that are mutually coupled, the first casing including a volute chamber therein and the second casing including an impeller installation space therein; an impeller provided in the impeller installation space so as to be rotatable around a rotation axis; and a vaneless diffuser that has an inlet that communicates with an inside of the second casing and has an outlet that communicates with an inside of the first casing. The vaneless diffuser has a width having a non-axisymmetric distribution in the circumferential direction.

Abstract: A centrifugal compressor includes an asymmetric self-recirculating casing treatment that includes, on an inner face of a casing 10, a suction ring groove 1, a ring guide channel 2 and a back-flow ring groove 3 to form a self-recirculating channel. An axial-direction position Sr from an upstream end face of the suction ring groove to an impeller full blade leading edge 4 or a width br of the suction ring groove 1 is represented as A(?·D??·D)2+A0 and is distributed in a parabolic shape in a circumferential direction. An initial phase angle ?0 is in a range of 0??0?2?. A circumferential angle ? of the casing has a definition range of ?0????0+2?. In the expression, A denotes a parameter of the parabola in the axial-direction position Sr or the width br, and A0 denotes an extreme of the axial-direction position Sr or the width br when corresponding circumferential angle ? and the ? are equal at an extreme point of distribution of the parabola.

Abstract: A centrifugal compressor includes an asymmetric self-recirculating casing treatment that includes, on an inner face of a casing 10, a suction ring groove 1, a ring guide channel 2 and a back-flow ring groove 3 to form a self-recirculating channel. A position or a width of the suction ring groove 1 is distributed in an arc shape in a circumferential direction, and the arc has a center angle ? in a range of 0<??30°.

Abstract: A centrifugal compressor includes: a volute casing including a first casing and a second casing that are mutually coupled, the first casing including a volute chamber therein and the second casing including an impeller installation space therein; an impeller provided in the impeller installation space so as to be rotatable around a rotation axis; and a vaneless diffuser that has an inlet that communicates with an inside of the second casing and has an outlet that communicates with an inside of the first casing. The vaneless diffuser has a width having a non-axisymmetric distribution in the circumferential direction.

Abstract: A centrifugal compressor includes an asymmetric self-recirculating casing treatment that includes, on an inner face of a casing 10, a suction ring groove 1, a ring guide channel 2 and a back-flow ring groove 3 to form a self-recirculating channel. An axial distance Sr from an upstream end face of the suction ring groove 1 to an impeller full blade leading edge 4 or a width br of the suction ring groove 1 is represented as A·sin(?+?0)+A0 and is distributed in a sinusoidal shape in a circumferential direction, an initial phase angle ?0 is in a range of 0°??0?360°, and a circumferential angle ? of the casing 10 has a definition range of ?0????0+360°. In the expression, A denotes amplitude of distribution of the axial distance Sr or the width br, and A0 denotes an average of the axial distance Sr or the width br.

Abstract: A centrifugal compressor has a casing 7. In the casing 7 is formed a back-flow channel 9 to return fluid from a downstream position of an impeller full blade leading edge 6a to an upstream position of the impeller full blade leading edge 6a. The back-flow channel 9 includes a suction ring groove 9a and a back-flow ring groove 9b. The suction ring groove opens at the downstream position on the inner face 7a of the casing 7, and extends in the circumferential direction. The back-flow ring groove opens at the upstream position on the inner face 7a, and extends in the circumferential direction. Distribution in the circumferential direction of the axial-direction position of the suction ring groove 9a or a width of the suction ring groove 9a is asymmetric with reference to the rotation axis.

Abstract: A centrifugal compressor includes an asymmetric self-recirculating casing treatment that includes, on an inner face of a casing 10, a suction ring groove 1, a ring guide channel 2 and a back-flow ring groove 3 to form a self-recirculating channel. A position or a width of the suction ring groove 1 is distributed in an arc shape in a circumferential direction, and the arc has a center angle a in a range of 0<?30°.

Abstract: A centrifugal compressor includes an asymmetric self-recirculating casing treatment that includes, on an inner face of a casing 10, a suction ring groove 1, a ring guide channel 2 and a back-flow ring groove 3 to form a self-recirculating channel. An axial-direction position Sr from an upstream end face of the suction ring groove to an impeller full blade leading edge 4 or a width br of the suction ring groove 1 is represented as A(?·D??·D)2+A0 and is distributed in a parabolic shape in a circumferential direction. An initial phase angle ?0 is in a range of 0??0?2?. A circumferential angle ? of the casing has a definition range of ?0????0+2?. In the expression, A denotes a parameter of the parabola in the axial-direction position Sr or the width br, and A0 denotes an extreme of the axial-direction position Sr or the width br when corresponding circumferential angle ? and the ? are equal at an extreme point of distribution of the parabola.