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In fig. 4.1(b) on the suction surface, the mass transfer rates also descend fast from the leading edge. Further away from the leading edge, the higher mainstream Reynolds number causes higher mass transfer rates and earlier turbulent transition. It can be found that the high mainstream turbulence intensity induces much earlier transition to turbulence on the suction surface.

In fig. 4.2, the same Sh numbers are normalized by the square root of the mainstream exit Reynolds numbers, respectively. On both pressure and suction surfaces, the data for low mainstream turbulence intensity (Tu=0.2%) but at different mainstream Reynolds numbers collapse to almost one curve before transition near the trailing edge. It clearly shows that the flows on the suction surface remains laminar from the leading edge until transition at about Ss/C = 1.2 for these cases, which agrees with the analysis of 2D flow near the blade done using Texstan. The high mainstream turbulence intensity flow of 12.0% causes earlier transition to turbulent flow on the suction surface. On the pressure surface, the flows are also laminar from the leading edge until the separation region around Sp/C = 0.15 — 0.20, downstream of which the reattached flows are affected by the unsteady Taylor-Gortler vortices for the low turbulence level cases.

In the same figures, data from Wang (1997) are also plotted for comparison. Same general trend is followed for all the data, which validates the present measurements.

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