Study On Heat Transfer Characteristics Of The Energetic Particles Porous Pocked-bed

Charge Temperature is an important parameter influencing firing distance of weapons greatly in military combat. In the past, the way to solve the problems in process of unsteady heat transfer of charge is to treat all components in bed as the single substance, or with a simple series and parallel heat transfer model to describe unsteady heat transfer process and variation feature of temperature. In fact, charge is mainly constituted by the propellant particles and other auxiliary elements. From the structure, the particle-packed-bed belongs to the porous medium, such process should take full account of the influence to the heat transfer which produced by the structure feature of porous packed-bed, rather than simply treated it as pure solid-phase substance.The research in paper treats the energetic particles porous pocked-bed as the porous media. According to the structural features of energetic particles packed bed include ball particle packed-bed and cylindrical particle packed-bed, the paper selects relevant heat transfer model to describe unsteady heat transfer process, and the formula of effective thermal conductivity for each model is derived. By programming the process, a comparison of the calculated and experimental values should verify rationality of each model. In addition, the paper simulates the actual process by numerical methods and image analysis method. The main work is as follows:(1) In order to provide the necessary basis for the follow-up study about the characteristics of temperature distribution and heat distribution, the experiment measuring the thermal parameters of propellant particles and the analysis about the characteristics of cross-sectional structure of the packed-bed are down. After that, the experiment measuring temperatures in different time of a few tested points has down at high temperature and low temperature environment, the experiment data can be used as a criterion to check the follow-up calculation.(2) According to the structural features of energetic particles packed bed include ball particle packed-bed and cylindrical particle packed-bed, the continuous media or fractal model is selected to describe the physical model respectively.The heat transfer equations under the model are established and the heat transfer process under the model by numerical methods has be simulated. On basis of the above calculation, which are in agreement with the actual test ones in experiment, the paper analyzes temperature field characteristics.(3) Combined numerical methods and image analysis method, the real unsteady heat transfer process of energetic particles packed bed has be simulated directly. It can be intuitive analyze the feature of temperature distribution and heat transfer in two particle types packed-bed mostly. The results show that the heat transfer model against the two particle packed-bed is feasible.