The purpose of this study is to establish a matching method between compressor and turbine.
General sizes of compressor and turbine are calculated by Howell's method and Ainley & Mathieson's method. Then, off-design performance of each component is calculated through numerical simulation. From the resulting characteristic curves, an equilibrium running line of the whole system is obtained and it is used to check whether this system is operating in a safe region or not.
Appropriate design parameters have been surveyed from literature and experimental loss-equations of Soderberg, Ainley, and Howell were applied in order to determine the general sizes of the compressor and the turbine.
From the results of the numerical simulation it was found that Howell's method was poor in predicting the surge line and the effect of stalling, but that Ainley & Mathieson's method could be used as a good prediction method for off-design performance.
The equilibrium running line of a sample calculation is not so satisfactory. However, if annular wall boundary layer thickness and the stalling effect would be taken into account, a better result could be expected.