A strategy of hob-grinding the cylindrical riblet surface for drag reduction by the grinding wheel with ordered abrasive pattern

Riblet surface is a biomimetic surface that not only has the ability to reduce surface drag resistance of mechanical products in fluids, but also improves surface hydrophobicity. Therefore, studying its manufacturing technology has practical significance for solving its engineering applications. In order to grind the riblet surface on the cylindrical workpiece, an innovative hob-grinding strategy for reducing drag on cylindrical riblet surfaces using superhard grinding wheels with spiral abrasive pattern has been developed. To achieve this strategy, firstly, based on the analysis of the geometric topology features of the riblet surface, an engineered CBN grinding wheel with spiral arrangement of abrasive particles was designed based on the principle of gear hobbing machining. Then, the relationship between hob-grinding parameters and abrasive particle arrangement parameters on the parameters of the ground riblets was analyzed, and the process measures to increase the number of riblets on the cylindrical surface, the ratio of the height to spacing of riblets, and the impact on the surface geometry of the riblets were explored. Finally, the surface of the cylindrical riblet surface was ground through experiments, and under the conditions of this experiment, a riblet surface was obtained that its spacing, height, and ratio of the height-spacing were 93.85 mu m, 14.65 mu m, and 0.156, respectively. The research results indicate that using this strategy can grind the cylindrical riblet surface, and the proposed process strategy of increasing the number of riblets and the ratio of the height to spacing is feasible.