Comparison of unshrouded impeller analysis and experiment

Aerospace Turbomachinery Flow Physics

“…In the other cases, the sensitivities were measured from the given performance graphs and there may be up to 10% error associated with this. Nevertheless the model estimates are within 40% of the published results [Ishida et al, 1981], [Goto, 1992] and [Williams et al, 2001]. Two of the three compressors exhibit lower sensitivity than the pump studied here and the model captures this trend.…”

“…The model was assessed against the computed results for the baseline and modified impellers presented in Section 6.3. Its applicability was also examined using impellers from Ishida et al [1981], Goto [1992] and Williams et al[ 2001]. With full input, the model captured the performance sensitivity within 20% difference interval of CFD results.…”

“…The design parameters for the modified pump (limited to first 80% of the impeller passage) are given in Table 6.2-2. This impeller is closer than the baseline one to the Rocketdyne impeller [Williams et al, 2001 ] in terms of specific speed and diffusion ratio. The tip clearance was created from the original shrouded design by reducing the blade height.…”

“…Performance parameters considered are static and stagnation pressure rise coefficient, efficiency, and blade loading variation (measured as the pressure difference across the blade). To apply the model to published results, we also define the information required for its use and assess the model against the information from representative impellers reported in Ishida et al [1981], Goto [1992] and Williams et al[ 2001].…”

“…In summary, the use of approximate input to the model has been assessed for two examples and found to agree within a 16% difference interval. The model is now applied to three reported impeller designs that were found to provide sufficient information: [Ishida et al, 1981], [Goto, 1992] and [Williams et al, 2001]. Overall design and geometrical information were given so the approximate expressions for velocity and loading derived in Section 6.5.3.1 were used.…”