Title

Experimental investigation of thermo-fluid effects in the grinding zone

Date of Completion

January 1995

Keywords

Engineering, Mechanical|Engineering, Materials Science

Degree

Ph.D.

Abstract

Grinding is a process of material removal using a grinding wheel. Virtually all the energy generated from the grinding process is converted into unavailable energy (heat energy). Coolant supply to remove heat effectively from the grinding zone is very important to prevent thermal damage to the workpiece. This experimental investigation is intended to provide the information about conditions necessary for a coherent coolant jet, and detailed measurements of fluid pressure under an operating grinding wheel for various working conditions.^ The test program began with a study of the conditions necessary for producing coherent jet. Tests have shown that the secondary flow generated from elbows normally fitted to a coolant pipeline has a significant influence on jet dispersion. To reduce the resulting secondary flow a flow conditioner has been designed and tested. Moreover, round converging nozzles based on Rouse, et al (1952) and a new rectangular nozzle with concave inner walls were designed and built. Jet coherency, therefore, has been improved to a greater degree than before.^ The coolant pressure measurements show fluid behavior in the grinding zone. The experimental data indicate that workpiece burn is associated with no negative gage pressure, where the temperature confirms that a typical film boiling process has occurred. The pressure measurements also demonstrate that a higher coolant pressure in grinding zone is a measure of improved cooling effectiveness. The coherent jet, presence of the workpiece sidewalls, and downcut grinding mode will increase the pressure reading to a certain degree. The jet direction into the grinding zone, and the use of electroplated superabrasive wheels also have significant effects on the measured pressure. ^