Axisymmetric design of axial turbomachines: an inverse method introducing profile losses.

The distributed loss model has been included in a time-marching Euler solver. This predicts the axisymmetric flow field and hub-to-tip stream surface geometry once the loading distribution is prescribed in the blade regions. The loss model replaces shear stresses with a suitable viscous force distribution, which does not work on the relative flow motion, but is only meant to produce entropy along the meridional streamlines. As in a fully inverse computation the flow angles are unknown, empirical loss correlations for single cascades cannot be used. The overall loss level through each blade row will be provided by the one-dimensional stage of the design process, then simplifying assumptions or specific correlations are used to estimate its spanwise distribution. The loss model effects on the flow field and stream surface geometry predicted by the inverse solver have been assessed.