A Reduced Order Model for Preliminary Design and Performance Prediction of Tapered Inducers

A reduced order model for preliminary design and noncavitating performance prediction of tapered axial inducers is illustrated. In the incompressible, inviscid, irrotational flow approximation the model expresses the 3D flow field in the blade channels by superposing a 2D crosssectional vorticity correction to a fully-guided axisymmetric flow with radially uniform axial velocity. Suitable redefinition of the diffusion factor for bladings with non-negligible radial flow allows for the control of the blade loading and the estimate of the boundary layer blockage at the specified design flow coefficient, providing a simple criterion for matching the hub profile to the axial variation of the blade pitch angle. Carter’s rule is employed to account for flow deviation at the inducer trailing edge. Mass continuity, angular momentum conservation and Euler’s equation are used to derive a si..