Prewhirl an Added Degree of Freedom to the Designer of Small Single-Shaft Gas Turbines

The possibility of the advantageous use of adjustable guidevanes in the compressor inlet for the control of single-shaft gas turbines is discussed. Considering certain design specifications that are impossible to be met by a fixed-geometry, single-shaft machine, it is pointed out how the design specifications can be met utilizing an inlet guidevane system. This is merely used as an example to point out the possible merits of such a system and that it may allow the designer to meet some extraordinary design requirements.