Notice of RetractionThe temperature modeling of the moving armored vehicle based on finite element method
Due to the decline of the viability and battle effectiveness of the electronic countermeasure armored vehicle caused by intense infrared radiation (IR), the temperature model is built for the IR characterizations of moving target. While taking the effect of radiation, convection and heat transfer into consideration, the mathematic description and simulation of the temperature model are carried out with finite element method (FEM) in the processes of sub-domains partition, node determination, control equation construction, boundary condition determination, equation discretization and iterated calculation. The comparison and analysis of the temperature distribution of typical parts between the simulated results of the FEM and the actual measured value are carried out with the same parameters. It indicates that the results with the application of the FEM approaches the actual measured value more with a better precision.
Atmospheric transparency′s effect on ground target′s infrared character
Atmospheric condition is an important factor to influence the ground target infrared character.After the circumstance factors to influence the target surface temperature are analyzed,the atmospheric transparency′s effect on ground target′s temperature is mainly discussed and the atmospheric effect to attenuate the infrared radiation is also simply discussed.Finally,the two effects are combined to analyze the atmospheric transparency′s comprehensive effects on infrared radiation character of ground target.The result indicates that although the high atmospheric transparency can reduce the target surface temperature in daylight,because of the atmospheric attenuation to infrared radiation,the overall effect is that the higher the atmospheric transparency is,the more intensive the target radiation received by space infrared detector is.
Numerical tools applied to power reactor noise analysis
In order to be able to calculate the space- and frequency-dependent neutron noise in real inhomogeneous systems in two-group theory, a code was developed for the calculation of the Green's function (dynamic transfer function) of such systems. This paper reports on the development as well as the test and application of the numerical tools employed. The code that was developed yields the space-dependence of the fluctuations of the neutron flux induced by fluctuating properties of the medium in the two-group diffusion approximation and in a two-dimensional representation of heterogeneous systems, for both critical systems and non-critical systems with an external source. Some applications of these tools to power reactor noise analysis are then described, including the unfolding of the parameters of the noise source from the induced neutron noise, measured at a few discrete locations throughout the core. Other concrete applications concern the study of the space-dependence of the Decay Ratio in Boiling Water Reactors, the noise-based estimation of the Moderator Temperature Coefficient of reactivity in Pressurized Water Reactors, the modeling of the beam- and shell-mode core-barrel vibrations in Pressurized Water Reactors, and the investigation of the validity of the point-kinetic approximation in subcritical systems driven by an external source. In most of these applications, calculations performed using the code are compared with at-power plant measurements. Power reactor noise analysis applications of the above type, i.e. core monitoring without disturbing plant operation, is of particular interest in the framework of the extensive program of power uprates worldwide.