Flow field characteristics of the wedge zone between a major flank and a transient surface

During metal cutting, a wedge zone can develop between the major flank surface at the tool tip and the transient workpiece surface; the flow field characteristics in the wedge zone are crucial for the cutting fluid to penetrate to the deformation zone. In this study, a mathematical model was established on the basis of boundary-layer theory for the workpiece surface layer during the turning process. According to an analysis of wedge zones, the flow field exhibits a negative pressure gradient. The pressure and velocity distributions of the flow field in the cutting region were analysed through computational fluid dynamics (CFD) simulation. The pressure distribution along the major flank, cutting speed direction from the tool tip to the plane of the shank bottom, velocity distribution along the wedge zone entrance, and tangential surface at workpiece bottom were obtained. The influences of workpiece rotation, workpiece diameter, and cut depth on the pressure distributions at the major and minor flanks were tested. The experimental results were consistent with the CFD solutions.