Effect of Variable Thermal Properties on Gun Tube Heating

Abstract

Repeated gun firings can steadily elevate the barrel temperature. The firing heat input and the resulting barrel temperature rise depend on the thermal properties of the barrel material. In particular, they depend on the thermal conductivity, specific heat, and mass density. Since conductivity and specific heat depend on barrel temperature, gun barrel heating becomes a nonlinear problem. If the temperature range is large, this temperature dependence can have an effect on the predicted barrel temperature change. We shall show how these effects are modeled by use of a finite difference solution to the one-dimensional (Fourier) equation of heat conduction. Our findings indicate that for the limited number of rounds stowed in a tank, the inclusion of temperature-dependent thermal properties does not have a significant effect on the predicted barrel temperature change. gun barrels; finite difference theory; thermal properties; M256 120-mm gun; multiple rounds; tar gun heating.