Axial Location

Axial Location

Figure 16. Variation of predicted mass flow with axial station through the low speed rig 1st stage for the baseline case and the case with hub leakage flow.

In both cases, the flow from the inlet of the H-grid to the beginning of the H-grid and O-grid overlap region was constant, showing good mass flow conservation for the pure H-grid region. In the overlap region of the vane O-grid and H-grid, both predictions show a gain of 0.12 lb./s or about 2% of the priraaiy flow. For the baseline case, the flow was constant from the end of the vane O-grid through the interface to the beginning of the blade O-grid. This behavior is expected, and showed that mass flow was conserved through the interface. For the case with hub mass-flow addition, there was a rise in mass flow at the location of the cavity, but this rise was not constant in the rotor H-grid. This behavior is probably due to the limited number of blade flow passages included in the post-processing or due to lack of numerical convergence. For the baseline case, there was an increase in mass flow through the rotor O-grid and H-grid overlap region. For the case with hub mass flow addition, there was a decrease through this region of the blade. Both cases show a blade exit flow of about 6.25 lb./s. From this plot, two conclusions can be drawn. (1) The mass flow through the stage was determined by the exit conditions. For both cases the specified exit static

proprietary rights legend This technical data and tha information embodied herein is the property of and proprietary to Rolls^Soyce Corporation, and shall not, without prior written permission of RoHs-Royce Corporation, be disclosed in whole or in part to dvrd parties. rtiic lagend chaJI be included on arty reproduction of Ihts data wboie or m parr. Copyright 2000 • RoHs-Royce Corporation, (unpublished)

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