Grinding of Riblets on Curved Paths

Abstract

The grinding of riblets with multiple profiled grinding wheels is an efficient method to minimize the fluid friction on surfaces. In turbo machinery components, like pump impellers or compressor blades, the riblets must be ground with a curved tool path since the flow is rarely linear on such surfaces. This leads to angular errors in the generated riblet profiles and therefore requires the use of grinding wheels with smaller diameters. The tool wear increases due to lateral strain on the peaks of the grinding wheel. Consequently, the increased wear and the need of smaller tool diameters decrease the efficiency of the process. In this paper a structuring process with dicing blades was investigated in order to increase the economic viability of this process. A dressing operation for such tools is not necessary and thus reduces the non-productive time of the manufacturing process. Furthermore, profile tip wear has no negative effects on the aspect ratio of the generated riblets since the riblet geometry is determined by the thickness of the dicing blades.

Micro-grooving of brittle materials using textured diamond grinding wheels shaped by an integrated nanosecond laser system

“…The surface roughness Sa was measured to be 2.1 µm on the ground surface. Compared to the method proposed in [34], where 6 thin dicing blades are assembled and carefully aligned on a shank to fabricate riblet structures on an impeller, the strategy developed in this paper requires only one laser conditioned grinding pin. Besides, the internal grinding wheel can be easily re-conditioned after wear, which significantly reduces the cost and increases productivity in the long term.…”