Compressor housing, compressor including the compressor housing, and turbocharger including the compressor

A compressor comprising:

• an impeller including a hub and a plurality of blades on an outer surface of the hub;
• and
• a compressor housing configured to rotatably house the impeller,
• wherein the compressor housing comprises:
• an intake flow path-forming section configured to form an intake flow path through which gas is introduced to the impeller from outside of the compressor housing;
• a shroud portion including a shroud surface curved in a protruding manner to face the plurality of blades such that a gap is between the shroud portion and a tip side edge of each of the plurality of blades;
• and
• a scroll flow path-forming section configured to form a scroll flow path through which the gas that has passed through the impeller is guided to the outside of the compressor housing,
• wherein at least one groove portion extending in a circumferential direction is defined in the shroud surface,
• wherein, in a cross-sectional view taken along an axis of the impeller, the at least one groove portion includes:
• a downstream side wall surface, wherein a distance from the axis of the impeller to the downstream side wall surface increases toward an upstream side from a downstream side end portion of the at least one groove portion;
• and
• an upstream side curved surface that is recessed between an upstream end of the downstream side wall surface and an upstream side end portion of the at least one groove portion, and configured to have a furthest upstream position which is further upstream than the upstream side end portion of the at least one groove portion,
• wherein the plurality of blades includes a plurality of full blades and a plurality of splitter blades, each of the plurality of splitter blades having a shorter extending length than each of the plurality of full blades,
• wherein, in the cross-sectional view taken along the axis of the impeller, the at least one groove portion is configured to satisfy a condition of 0.2≤Z/L≤1.2, where L represents a distance from a hub end of a trailing edge of each of the plurality of full blades to a tip end of a leading edge of each of the plurality of full blades in an extending direction of the axis of the impeller, and Z represents a distance from the hub end of the trailing edge of each of the plurality of full blades to the upstream side end portion of the at least one groove portion in the extending direction of the axis of the impeller, and
• wherein a leading edge of each of the plurality of splitter blades is downstream of the at least one groove portion.