Tandem Grid in a Single Stage Axial Blower

摘要

In order to achieve high pressure factors in a singlestage axial blower, rotor and stator were equipped with tandem grids. Optimum arrangements of the partial grids were found for different ratios of the diameters. A com parison with the blade arrangements of single-row grids, which were designed for the same pressure and delivery factors, showed that tandem grid blading has better efficiency coefficients and a more advantageous position of the separation point. The tandem grids were especially advantageous in the case of relatively short blades. The pressure factor could be strongly varied through turning of the blades of the second rotor partial grid at an only slightly changed delivery factor, whereby the efficiency coefficient showed only small changes. Measurements in the flow behind the grids and observations of the boundary layers provided statements on the blade losses at tandem grids and at single-row grids. (Author)