Loss of kinetic energy at the entry to a moving blade

1 Loss of kinetic energy at the entry to a moving blade 

Rgnre 15.4 Showing the directions of approach to the tip of the moving biade for off-design speed ratios. 

Accordingly, solving (15.60) and (15.61) gives the fraction of flow diverted to the outside of the blade as 

We will assume that some fraction ci, 0 ci 1 of the kinetic energy associated with the diverted flow will be lost, so that the fractional loss of kinetic energy will be  

This fraction of the kinetic eneigy possessed by the mid-stage gas stream will be converted into additional enthalpy. There is no mechanism for reconverting this enthalpy into kinetic energy in an impulse blade, so there will be no recovery of any energy lost at the blade entry in an impulse stage. A reasonable estimate may be 1. The loss correction factor to be applied to the initial value of blade efficiency is simply (l-X ). The final calculation of blade efficiency for an operating impulse blade is thus 

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