Reconstruction of the heat flux input of coated gun barrel with the interfacial thermal resistance

Abstract

A 2-D inversion model to reconstruct the transient inner wall heat flux of the coated barrel is proposed in this paper. Indirect measurement of the inner wall temperature of the barrel under harsh conditions is realized. Measurement points locate at specified distances from the inner surface. Temperature calculated from a direct problem plus the measurement errors is taken as measured temperature. Variations of the temperature dependent thermo-physical properties of materials are taken into consideration. The total heat input of the firing and thermal resistance between chromium coating and gun steel are determined by depths of gun steel phase transition and chromium recrystallization after firing. The direct problem, sensitivity problem and adjoint problem are solved with the finite difference method (FDM). After verifying the reliability of the inversion model with a special numerical example, it is promoted to reconstruction of general heat flux varying with time and space. Results indicate that decreasing the measurement error and increasing the number of measurement points can effectively improve the performance of the model. As well, measurement points closer to the inner wall offer superior accuracy. The inversion model herein can serve as a promising indirect measurement method of the inner wall temperature.