Handbook of Turbomachinery Second Edition Revised - Ventech!

By assuming that Vy2 is zero, Eq. (23) reduces to
Vy1 ¼ lUm ¼ð1:3Þð891:6ft= secÞ ¼1159:1ft= sec
Using Eqs. (10) through (14) results in the vector diagram shown in Fig. 14.
Note that the critical stator and rotor exit angles are within the guidelines
presented earlier.
The rotor blade height and mean radius are determined by the
required rotor exit flow area and the hub-to-tip radius ratio. The rotor exit
flow area is determined from continuity:
A2 ¼ r 2Vx2
_m
The mass flow rate and axial velocity have previously been calculated;
the density is dependent on the rotor exit temperature and pressure. For a
turbine without a diffuser, the rotor exit static pressure is the same as the
discharge pressure, assuming the rotor exit annulus is not choked. For a
Figure 14 Mean-radius velocity diagrams for first iteration of axial-flow turbine
sizing example.
Copyright © 2003 Marcel Dekker, Inc.