Grinding of Riblet Structures on Free Formed Compressor Blades

Grinding of Riblet Structures on Free Formed Compressor Blades

Categories Zeitschriften/Aufsätze (reviewed)
Year 2014
Authors Denkena, B., Köhler, J., Krawczyk, T.:
Published In Advanced Materials Research Vol. 907 (2014), S. 463-473.

The effectiveness of gas turbines can be improved significantly by decreasing the friction losses. Compared to smooth surfaces riblet-structures have been proven to reduce skin friction in turbulent flow up to 10 %. For the technical application on compressor blades in turbo machines, micro riblet-structures with a riblet width between 20 μm and 120 μm and a depth of the half width are required. Furthermore, the application on compressor blades needs ideal riblet-geometries with an aspect ratio of 0.5, trapezoid groove geometry and a shape accuracy of the compressor blade about 10 μm. This paper presents the relevant influencing factors on the overall shape accuracy as well as the riblet geometry in five axes grinding of riblet-structures on double curved compressor blades. The results show, that the shape accuracy is affected by the CAD data and the macrogeometry of the grinding wheel. Therefore, specialized requirements on the CAD data were defined in order to increase the shape accuracy. To decrease the influence of the grinding wheel geometry on the overall shape geometry, a method adjusting the grinding wheel geometry on double curved surfaces was developed. Furthermore, the effect of the 5 axes kinematic on the aspect ratio and the profile wear was examined.

DOI 10.4028/