TURBOCHARGER ASSEMBLY

1 . A turbocharger assembly, comprising:

a turbine housing defining an exhaust inlet opening and an exhaust outlet opening;

a turbine wheel housed in the turbine housing;

a compressor housing defining an air inlet opening and an air outlet opening;

a compressor wheel housed in the compressor housing; and

a shaft coupling the turbine wheel to the compressor wheel,

wherein at least one of the turbine housing, the turbine wheel, the compressor housing, and the compressor wheel includes a surface comprising a plurality of protrusions or depressions.

2 . The turbocharger assembly of claim 1 , wherein a shape of the protrusions or depressions is selected from the group of shapes consisting of semi-spheres, prisms, pyramids, and cones.

3 . The turbocharger assembly of claim 1 , wherein a width of the protrusions or depressions is from approximately 1.5 mm to approximately 9.5 mm.

4 . The turbocharger assembly of claim 1 , wherein a height or depth of the protrusions or depressions is from approximately 0.5 mm to approximately 6.5 mm.

5 . The turbocharger assembly of claim 1 , wherein the compressor wheel comprises:

a plurality of blades each having a leading edge and a trailing edge; and

a plurality of protrusions or depressions proximate the leading edges of the blades.

6 . The turbocharger assembly of claim 1 , further comprising a thermal barrier coating on at least one of the turbine housing, the turbine wheel, the compressor housing, and the compressor wheel.

7 . The turbocharger assembly of claim 6 , wherein the thermal barrier coating comprises an aluminum-filled ceramic.

8 . The turbocharger assembly of claim 1 , further comprising a plurality of axial grooves circumferentially disposed around an inner surface of at least one of the air inlet opening, the air outlet opening, the exhaust inlet opening, and the exhaust outlet opening.

9 . The turbocharger assembly of claim 1 , further comprising a plurality of helical grooves disposed around an inner surface of at least one of the air inlet opening, the air outlet opening, the exhaust inlet opening, and the exhaust outlet opening.

10 . The turbocharger assembly of claim 9 , wherein the helical grooves are spaced apart by approximately 2.5 mm to approximately 12 mm.

11 . The turbocharger assembly of claim 9 , wherein the helical grooves are angled from approximately 15 degrees to approximately 60 degrees relative to an axis of the inner surface.

12 . The turbocharger assembly of claim 9 , wherein the plurality of protrusions or depressions are provided within the helical grooves.

13 . The turbocharger assembly of claim 9 , wherein the plurality of protrusions or depressions are not provided within the helical grooves.

14 . The turbocharger assembly of claim 1 , wherein the air inlet opening of the compressor housing tapers between a wider outer end and a narrower inner end.

15 . The turbocharger assembly of claim 1 , wherein the exhaust inlet opening of the turbine housing tapers between a wider outer end and a narrower inner end.

16 . The turbocharger assembly of claim 1 , wherein the turbine wheel comprises a plurality of blades having rounded edges.

17 . A compressor assembly, comprising:

a compressor housing defining an air inlet opening and an air outlet opening;

a compressor wheel housed in the turbine; and

a shaft coupled to the compressor wheel,

wherein at least one of the compressor housing and the compressor wheel includes a surface comprising a plurality of protrusions or depressions.

18 . The compressor assembly of claim 17 , wherein a shape of the protrusions or depressions is selected from the group of shapes consisting of semi-spheres, prisms, pyramids, and cones.

19 . The compressor assembly of claim 17 , further comprising a plurality of grooves disposed around an inner surface of at least one of the air inlet opening and the air outlet opening.

20 . A turbocharger assembly, comprising:

a turbine housing defining an exhaust inlet opening and an exhaust outlet opening, the exhaust openings each including a surface comprising a plurality of protrusions or depressions and a plurality of grooves;

a turbine wheel housed in the turbine housing including a surface comprising a plurality of protrusions or depressions;

a compressor housing defining an air inlet opening and an air outlet opening, the openings each including a surface comprising a plurality of protrusions or depressions and a plurality of grooves;

a compressor wheel housed in the compressor housing including a surface comprising a plurality of protrusions or depressions; and

a shaft coupling the turbine wheel to the compressor wheel.

21 . The turbocharger assembly of claim 20 , wherein a shape of the protrusions or depressions is selected from the group of shapes consisting of semi-spheres, prisms, pyramids, and cones.

22 . The turbocharger assembly of claim 20 , wherein at least one of the exhaust inlet opening, the exhaust outlet opening, the air inlet opening, and the air outlet opening tapers between a wider outer end and a narrower inner end.