The decision was made to use a heavy-duty, 12-stage transonic compressor for the new Type 8 Brown Boveri gas turbine.
With this advanced concept, it became possible both to increase the pressure ratio to 16:1 and to reduce the number of stages by half. The wide-chord, low aspect-ratio blade design brought about a further decrease in the total number of components and a reduction of the mechanical stresses. A variable inlet guide vane was added to provide flexibility in combined cycle operation.
Appropriate computer-assisted design systems were developed for evaluation of design and off-design aerodynamics.
As a back-up for the design work, tests were run on several model compressors to explore and study aerodynamic and mechanical behavior. Detailed field measurements were also taken on the prototype units of the Type 8 as a final check to confirm the expected values.
