Abstract: An airfoil diffuser for a centrifugal compressor formed by a diffuser passage area and a plurality of diffuser blades located within the diffuser passage area. The diffuser passage area is defined between a hub plate and a shroud of the centrifugal compressor. Each of the diffuser blades has a twisted configuration in a stacking direction as taken between the hub plate and an outer portion of the shroud located opposite to the hub plate. As a result of the twisted configuration, the diffuser blade inlet blade angle decreases from the hub plate to the outer portion of the shroud and solidity measurements at leading edges of the diffuser plates vary between a lower solidity value measured at the hub plate of less than 1.0 and a high solidity value measured at the outer portion of the shroud of no less than 1.0.

Abstract: A compressor having a defined large diameter impeller having an integral shroud and having a three dimensional gas flow path defined by the impeller hub surface, blades and the shroud and having a large axially oriented inlet or inducer section with aggressive inducer blades, a defined outlet section geometry, and continuous blade geometries between the inlet and outlet sections.

Abstract: A low solidity vaned airfoil diffuser for a centrifugal compressor wherein each blade has a lean angle greater than zero and wherein the hub stagger angle may be the same as or may be different from the shroud stagger angle for each blade.