Theoretical analysis of the surface temperature regulation of an infrared false target subjected to periodical ambient conditions

Infrared false target is an important mean to induce the infrared-guided weapons, and the key issue is how to keep the surface temperature of the infrared false target to be the same as that of the object to be protected. One-dimensional heat transfer models of a metal plate and imitative material were established to explore the influences of the thermophysical properties of imitative material on the surface temperature difference (STD) between the metal plate and imitative material which were subjected to periodical ambient conditions. It is elucidated that the STD is determined by the imitative material's dimensionless thickness (dim*) and the thermal inertia (Pim). When dim* is above 1.0, the STD is invariable as long as Pim is a constant. And if the dimensionless thickness of metal plate (dm*) is also larger than 1.0, the STD approaches to zero as long as Pim is the same as the thermal inertia of metal plate (Pm). When dim* is between 0.08 and 1, the STD varies irregularly with Pim and dim*. However, if dm* is also in the range of 0.08-1, the STD approaches to zero on condition that Pim=Pm and dim*=dm*. If dim* is below 0.08, the STD is unchanged when Pimdim* is a constant. And if dm* is also less than 0.08, the STD approaches to zero as long as Pimdim*=Pmdm*. Furthermore, an application-oriented discussion indicates that the imitative material can be both light and thin via the application of the phase change material with a preset STD because of its high specific heat capacity during the phase transition process.