Abstract: A set of equations has been derived for through-flow fields in multi-stage axial-flow compressors, and all the spanwise mixing effects in a unified form are presented, including both turbulence and secondary flows. The relations have been discussed between three-dimensional shear structures of the compressors flow fields and the turbulent mixing effects in the two-dimensional throughflow fields. It has been found that the turbulent mixing in the two-dimensional throughflow fields is determined by the three-dimensional shear structures, rather than the two-dimensional shear structures alone. From the comparison of the computational results of the equations and experimental results as well as the results of Gallimore's mixing calculations, it has been shown that the characteristics of spanwise mixing can be modeled better by applying these equations.

Key words: axial flow compressor, spanwise mixing, turbulent diffusion