双基药燃烧产物热物性参数计算分析

Calculation and Analysis of Thermophysical Parameters of Double Base Propellant Combustion Products

为准确获得双基药燃烧混合气体生成物的热物性参数,求解火药燃烧产生的高温气体与身管内壁面的对流换热系数以及火炮发射过程中内壁面的温度,根据双基药组分,给出了火药燃烧化学反应方程式,计算得到燃烧生成物各组分的含量。基于已有的标准大气压下CO_(2)、CO、H_(2)O(g)、H_(2)和N_(2)的动力黏度、导热系数、比定压热容随温度的变化实测数据,采用最小二乘法拟合得到双基药燃烧混合气体生成物的热物性参数计算模型,并针对3种典型的双基药进行计算分析。结果表明:最小二乘法拟合得到的计算模型可以较好地应用于标准大气压下纯气体热物性参数的求解;气体的动力黏度、导热系数和比定压热容均随着温度的升高而增大;硝化棉含氮量越高,导热系数和比定压热容值越小,硝化棉含氮量对混合气体的动力黏度值影响较小,可忽略不计。

The thermophysical parameters of gas mixture production generated by double base propellant combustion can be used to solve the convection heat transfer coefficient between the high-temperature gas produced by propellant combustion and the inner wall surface of the barrel as well as calculate the temperature of the inner wall surface during gun firing.The chemical reaction equations of propellant combustion were established based on the components of double base propellant,and the content of each component of combustion production was calculated.Based on the existing data of pure gas which related to temperature at standard atmospheric pressure,the correlations of dynamic viscosity,thermal conductivity and specific heat capacity at constant pressure of CO_(2),CO,H_(2)O(g),H_(2) and N_(2) with temperature under standard atmospheric pressure were obtained by least square method.The calculation and analysis of three typical double base propellants were carried out.The results show that the calculation models fitted by the least square method can be well applied to solve the thermophysical parameters of pure gas at standard atmospheric pressure.The dynamic viscosity,thermal conductivity and specific heat capacity at constant pressure of the gas increase with the increase of temperature.The higher the nitrogen content of nitrocellulose is,the smaller the thermal conductivity and specific heat capacity at constant pressure are.The influence of nitrogen content of nitrocellulose on the dynamic viscosity of gas mixture is negligible.