Numerical Simulation of Airflow Field in Grinding
With a view to find better ways for coolant delivery, the boundary layer of peripheral air of grinding wheel is simulated using finite volume method. By means of introducing Sparlart-Allmaras (SA) model into the mathematical model, the airflow field is calculated and pressure distributions and velocity distributions are obtained by simulations. An experiment is run to testify solutions of numerical simulation accordingly. The simulation solutions are in consistent with the experiment results on the whole. Therefore, this simulation method holds true for predicting the performances of airflow field around grinding wheel when grinding wheel rotates at high speeds. Based on the numerical solution results obtained in this paper, the causes to disadvantage of coolant delivery into the grinding zone are studied from the point of view of the pressure and velocity. In the end, one optimizing way of coolant delivery is specified and a few useful conclusions are drawn for applications of coolant delivery in the course of high speed grinding. Methods and conclusions of this research are available for perfection of grinding theory and applications of cooling in the future.
Application of Lubrication Theory to Fluid Flow in Grinding: Part II—Influence of Wheel and Workpiece Roughness
The objective of this study is to model fluid flow in grinding with nonporous wheels. While Part I focused on the flow in a simplified smooth geometry, in this part the wheel surface roughness is introduced. The applicability of the modified Reynolds equation for laminar flows between rough surfaces is verified experimentally in terms of the developed hydrodynamic pressure, using a resin-bonded diamond grinding wheel. The experiments were performed under the spark-out condition (i.e., with the wheel just touching the workpiece) and in actual grinding. Agreement between theory and experiment is shown for Re <100, but a significant discrepancy (most likely due to turbulence) is observed for 300
A model for the topography of diamond grinding wheels
Abstract A mathematical model is presented to characterize the topography of a freshly dressed resin/metal bonded diamond grinding wheel. The planar grain density, the area due to exposed abrasives and the abrasive protrusion height distribution of a wheel are estimated with regard to the grit size and volumetric concentration of the abrasives. The model indicates that the protrusion height is approximately uniformly distributed and the percentage of area due to exposed abrasives on the wheel surface is independent of the abrasive grit size for a particular concentration.