Experimental and numerical investigations of the effect of charge density and scale on the heat transfer behavior of Al/CuO nano-thermite

In this paper, to study the propagation behavior and the burning rate enhancement of Al/CuO nano-thermite in confined burn tubes, modification of the component was achieved by introducing energetic binder nitrocellulose (NC). The combustion behavior of Al/CuO and Al/CuO@NC nano-thermites in burn tubes was contrastively investigated by turning the charge density and the tube diameter in the range of 0.8-1.8 g/cm(3) and 0.3-2 mm, respectively. Our experiments and theoretical calculation results show that the seepage of the gas flow is an important factor affecting the heat transfer process of Al/CuO nano-thermite in burn tubes, which makes the propagation velocity decrease with the increase of the charge density. Meanwhile, by introducing a certain amount of NC into the component, the reactivity can be improved while the gas production and pressurization capacity can be increased at the same time. This can greatly improve the propagation velocity of Al/CuO nanothermite under constraint conditions. Moreover, with the decrease of the tube diameter, it can be inferred that the significant increase of the relative heat loss is the main reason for the decrease of the propagation velocity while the dimensionless parameter theta can be used to analyze the heat loss coefficient under different charge diameters.

Automated summary

The experimental and theoretical results indicate that gas flow seepage is a critical factor affecting the heat transfer process of Al/CuO nano-thermite in burn tubes, leading to a decrease in propagation velocity with increasing charge density. Introducing a certain amount of NC into the component can improve reactivity and increase gas production and pressurization capacity, significantly enhancing the propagation velocity of Al/CuO nanothermite under constraint conditions. Additionally, the increase in relative heat loss with decreasing tube diameter is the main reason for the decrease in propagation velocity, and the dimensionless parameter theta can be used to analyze the heat loss coefficient under different charge diameters.