Seventh standard configuration (compressor cascade in supersonic flow)
2D geomertry file: stcf7_geo.zip (2 KB)
File InformationThe seventh standard configuration (Fig. 3.7.1 and Tables 3.7.1-2) was tested at Detroit Diesel Allison, and included in the workshop report by courtesy of the sponsoring agent, D. R. Boldman at NASA Lewis Research Center [Boldman, 1983; Riffel and Rothrock, 1980]. A question as regards to the validity of the profile coordinates did arise at the 1991 Aeroelasticity meeting. These have been verified [Boldman, 1991], and it is confirmed that the originally presented blade coordinates were correct. The agreement between the data and the predictions is, at the present time, not satisfactory for any of the 12 aeroelastic sample cases. It is probable that some of the discrepancies comes from the viscous effects in the experiment, some from experimental accuracy and some from the prediction models, but not enough predictions have been performed to analyze either the data or predictions for supersonic cascades with thickness. At the present time it is thus proposed to keep this standard configuration, and the corresponding aeroelastic sample cases, in its original form. It should be pointed out that, as with the other experimental Standard Configurations, the pressure coefficients are scaled with the steady-state upstream dynamic pressure . As far as the authors are aware, all predicted results have been presented with this dynamic pressure in the pressure coefficient definitions. The Reynolds number of the experiments were not given in the original report [Bölcs and Fransson, 1986], but are now included. They are situated in the range 1.1-1.6•106 [Riffel and Rothrock, 1980, p. 11] for the performed tests. Gerolymos et al [1990] have presented calculations on this geometry. A stream sheet contraction of 0.85 was introduced for these computations in order to get a reasonable agreement with the steady-state outflow data. Trend wise agreement can be found in the unsteady pressures on the blade surfaces, and the experimental and numerical stability limits of the cascade agree fairly well.