We’re always trying to eke out more power from less. All the talk about green design and sustainability is really a way in which we can live our lives and power our machines using fewer resources: not just because it’s environmentally friendly but because it’s cheap as well.
Compressors play a large role in making our machines more efficient and more powerful. Thermodynamically a compressor is the same thing as a pump only a compressor works on gas or vapor and a pump operates on liquid but both typically increase the pressure of the working fluid. The pump may be increasing the pressure to increase flow but the compressor might be making a vapor more dense for its next stage in the process.
The most common compressors are axial flow and centrifugal types. In an engine, a compressor is usually housed in a turbocharger where the purpose is to increase density in the inlet manifold. For automotive applications the compressor wheel is on the same shaft as a turbine rotor which spins on exhaust gas while the compressor turns atmospheric air into compressed air.
I talked before about bearings are and how important material selection is there. The same goes for your compressor wheel and your turbine blade. Tiny imperfections can lead to wear of other materials (like your bearings) and continual loss of efficiency. Real problems can occur when the wheel cracks or chips. It’s a fine line to walk, but a necessary one if we continue to be demanding to our hardware and try to scrape out that last tenth of a percentage of efficiency.