Study on flow field and convective heat transfer characteristics in grinding zone of large spiral angle flow disturbance grooved wheel

Abstract

Abstract In view of the high specific removal energy, high heat generation rate, low heat transfer efficiency, easy to produce local high temperature and grinding burns, new macro-structured grinding wheel forms were proposed, namely, Large Spiral-angle Grooved Grinding Wheels (LSG-GW, β > 85°) and Large Spiral-angle flow Disturbance Grooved Wheels (LSDG-GW). Considering the influence of wheel parameters, groove parameters and process parameters, an analytical model of the airflow field in the wedge area and contact area of LSG-GW was established. Analytical model of gas-liquid two-phase flow field and theoretical model of convective heat transfer coefficient distribution in heat transfer channels were established. The results showed that increasing the groove width, groove depth and the spiral angle can reduce the pressure of the flow field in the air barrier layer and make it easier for the grinding fluid to enter the grinding contact area. The LSDG-GW further reduces the grinding fluid back flow and side flow intensity, proving that the flow disturbance structure can bring in more grinding fluid into the grinding contact area. A theoretical model for the distribution of convective heat transfer coefficient in the grinding contact area was derived, and the analysis results proved that the flow disturbance structure can significantly improve the convective heat transfer coefficient in the grinding contact area. The LSDG-GW, as a new macro surface structured grinding wheel, has a very promising application in the high efficiency and high precision grinding process of difficult-to-machine alloy materials.