Analysis of reverse heat transfer for conventional and optimized lubri-cooling methods during tangential surface grinding of ABNT 1020 steel

Abstract A numerical thermal model was developed to evaluate the heat flux which is conducted to a rectangular workpiece of steel plate ABNT 1020, thus making it possible to compute the maximum temperature in the grinding surface, taking into account the rectangular distribution of heat flux, the thermal properties of the grinding wheel conventional Al2O3, the piece to be machined and the lubri-refrigerating fluid. The finite volume method was employed for the discretization of the direct thermal problem from the heat diffusion equation associated with the two-dimensional problem of heat conduction in transient regime. The inverse thermal problem was solved by the Golden Section technique. The thermal flux, when compared to the conventional technique of method of application fluid, was reduced by 84.0% in the practices performed with cutting depth of 30µm, at 74.0% in practices with cutting depth of 45µm and 61.2% in the aggressive practices of 60µm, thus demonstrating the applicability of the optimized method for fluid application.

摘要：本研究构建数值热模型，以评估传导至ABNT 1020钢板矩形工件的热通量，进而可在考量热通量矩形分布、常规氧化铝（Al₂O₃）砂轮的热物性参数、待加工工件特性以及润滑冷却液特性的前提下，计算磨削表面的最高温度。针对瞬态二维热传导问题对应的热扩散方程，本研究采用有限体积法对直接热问题进行离散化处理，并通过黄金分割法求解逆热传导问题。相较于传统流体施加技术，采用优化流体施加方法后，热通量在切削深度30μm的试验中降低84.0%，切削深度45μm的试验中降低74.0%，切削深度60μm的严苛试验工况中降低61.2%，由此证明了该优化流体施加方法的适用性。