Transient thermal stress distribution in a circular pipe heated externally with a periodically moving heat source

This study presents the effects of periodically moving heat source on a circular steel pipe heated partly from its outer surface under stagnant ambient conditions. While the pipe is heated with this heat source applied on a certain section having a thickness of heat flux, the water flows through it to transfer heat. It is assumed that the flow is a fully-developed laminar flow. The heat source moves along from one end of the outer to the other end with a constant speed and then returns to the first end with the same speed. It is assumed that the heat transfer rate has a constant value, and that the thermo-physical properties of the steel do not change with temperature (elastic analysis). The numerical calculations have been performed individually for a wide range of thermal conductivity of steel and for different thicknesses of heat flux. The moving heat source produces the non-uniform temperature gradient and the non-uniform effective thermal stress, and when it arrives at the ends of the pipe, the temperature and effective thermal stress ratio profiles rise more excessively. The tangential component is more dominant in the effective thermal stress than the radial component.

► Moving heat source produces non-uniform temperature gradients and thermal stresses.
► When moving heat source arrives at ends of pipe, temperature gradients rise excessively.
► With increasing of heat flux thickness and thermal conductivity, the temperature gradients reduce.
►  Temperature gradients in thermal boundary layers slightly increase.
► Tangential component is more dominant in thermal stress than radial component.