Numerical solutions of transient conjugate heat transfer and thermally induced stress distribution in a heated and rotating hollow disk

Thermally induced stresses are taken into consideration as important phenomena in many manufacturing processes and design applications. Stress analysis is subsequently performed using the temperatures derived in the thermal analysis. The aim of this study is to calculate the transient temperature and thermally induced stress distributions in a rotating hollow disk, which is subjected to a thermal process by keeping its temperature within a certain desired interval for a certain time. The disk considered for this purpose was uniformly heated from the inner and bottom surfaces in cases A and B, respectively, and cooled from the top and outer surfaces with water. The heat flux applied on the surface was regularly increased and decreased depending on the maximum temperature of the disk during the thermal process to keep the maximum temperature of the disk within a certain desired interval (the temperature controlled heating case). In this heat flux regulating process, values of the heat transfer rate, Q, were selected as 1257 and 125.7 W for the high and low heat flux cases, respectively. The calculations were performed individually for various coolant velocities, U-c = 0.1, 0.2,...,0.5 m/s under transient conditions. In the temperature controlled heating case, the maximum temperature and thermal stress profiles continue as periodic curves with logarithmically increasing periods in case A and a constant period in case B after the maximum temperature value reaches the desired upper temperature limit (100 degreesC). In the cases of U-c = 0. 2-0.5 m/s of case B, since the maximum temperature levels do not exceed the desired upper temperature limit, the maximum temperature and thermal stress profiles increase logarithmically until the system reaches steady state. The effective stress ratio profiles at the bottom surface are higher with respect to those at other planes in the axial direction, and their maximum values vary in the range of 0.044-0.22 as parallel to the relevant temperature profiles. The results of this study clearly demonstrate the numerical solutions of transient temperature and thermally induced stress distributions in the considered disk. (C) 2004 Elsevier Ltd. All rights reserved.