Centrifugal compressor and turbocharger

A centrifugal compressor comprising:

• an impeller;
• a compressor inlet flow path that guides a fluid to the impeller;
• and
• a fluid introduction flow path that is connected to the compressor inlet flow path in a direction intersecting an axis of the compressor inlet flow path and that introduces the fluid into the compressor inlet flow path, wherein
• with respect to an end edge on an outlet side of the fluid introduction flow path in a flow path wall surface of the fluid introduction flow path, when a distance between a most upstream position in an axial direction of the impeller in the end edge and the axis of the compressor inlet flow path is denoted as A1, a distance between a most downstream position in the axial direction in the end edge and the axis is denoted as A2, a distance between a most upstream position in a rotation direction of the impeller in the end edge and the axis is denoted as A3, and a distance between a most downstream position in the rotation direction in the end edge and the axis is denoted as A4, A1 and A2 are different from each other, and A3 and A4 are different from each other.

A centrifugal compressor comprising:

• an impeller;
• a compressor inlet flow path that guides a fluid to the impeller;
• and
• a fluid introduction flow path that is connected to the compressor inlet flow path in a direction intersecting an axis of the compressor inlet flow path and that introduces the fluid into the compressor inlet flow path, wherein
• Condition (A) below or Condition (B) below is satisfied:
• Condition (A):
• in a cross section along an axial direction of the impeller, an angle formed between a flow path wall surface of the compressor inlet flow path and a flow path wall surface of the fluid introduction flow path on an upstream side of an axis of the fluid introduction flow path in the axial direction is less than 90 degrees, and in a cross section orthogonal to the axial direction of the impeller, an angle formed between the flow path wall surface of the compressor inlet flow path and the flow path wall surface of the fluid introduction flow path on an upstream side of the axis of the fluid introduction flow path in a rotation direction of the impeller is less than 90 degrees;
• and
• Condition (B):
• in a cross section along the axial direction of the impeller, the flow path wall surface of the compressor inlet flow path includes a first convex portion at a position on an upstream side in the axial direction with respect to an outlet of the fluid introduction flow path, and in a cross section orthogonal to the axial direction of the impeller, the flow path wall surface of the compressor inlet flow path includes a second convex portion at a position on an upstream side in the rotation direction of the impeller with respect to the outlet of the fluid introduction flow path.