Stress Evaluation Charts for Thermal Stratification Considering Heat Transfer Characteristics

Both temperature and thermal stress were theoretically analyzed for cylindrical vessels subjected to thermal stratification of contained fluid. Two kinds of temperature analysis results were obtained such as the exact temperature solution with eigenfunction series and the simple approximate one by the temperature profile method. Furthermore, thermal stress shell solutions were obtained for the simple approximate temperatures. Through comparison with FEM analyses, these solutions were confirmed to be adequate. The simple temperature solution is described by one parameter that is the temperature attenuation coefficient. The thermal stress shell solutions are described by two parameters. One is the ratio between the temperature attenuation coefficient and the stress decay coefficient. Another is the non-dimensional width of stratified layer. These solutions were condensed to the simplified thermal stress evaluation charts described by few design parameters. These charts enable quick and accurate thermal stress evaluations of cylindrical vessel subjected to thermal stratification, compared with conventional methods.