The Effects of the Cooling Gallery Position on the Piston Temperature Field and Thermal Stress

The effects of cooling gallery position on the piston temperature field and thermal stress are studied. A finite element model of 1015 engine piston is developed using Pro/E software and finite element analyses are achieved through ANSYS code. Numerical simulations are performed to find the temperature and thermal stress change rules with regard to the cooling gallery position. The results demonstrate that the axial direction position of cooling gallery has obvious effects on the piston temperature while the radial direction position of cooling gallery affects the piston thermal stress a lot. The highest position of cooling gallery should be as the same line as the top of the first ring groove. The distance between cooling gallery and piston radial edge should be more than a certain value to decrease the temperature gradient and thermal stress concentration.

Thermal Stress of Blast Furnace Hearth Linings under Erosion State

The structure of cooling stave was simplified with equivalent convective heat transfer coefficient, and the thermal stress axisymmetric calculation model of blast furnace hearth linings under erosion state was established. The thermal stresses of familiar erosion states were analyzed. The thermal stress concentration of erosion part is an importance cause of erosion development. ‘Elephant-foot’ erosion seldom develops to ‘boiler-bottom’ erosion. ‘Boiler-bottom’ erosion is a ideal long life erosion state. When the erosion stabilizes, smaller cooling intensity is favorable to linings stabilization.