炸药爆轰热力学数据非线性拟合方法研究

Nonlinear Fitting Method of Thermodynamic Data of Detonation Products and Its Application

利用最小二乘法拟合得到炸药爆轰产物热力学数据的非线性拟合方程。为了验证此方程的准确性,分别采用Kast平均热容法和非线性拟合法计算物质的焓变(H T-H 298),并与理论值比较。结果显示:非线性拟合法计算值最大误差为0.5%;Kast平均热容法的计算最小误差为3.1%,最大误差为12.5%。为实现爆轰参数的编程计算和验证非线性拟合法计算爆轰参数的可行性,根据前期研究成果,选取BKW状态方程作为爆轰产物的状态方程,利用最小自由能原理和Hugoniot关系,建立求解数学模型,分别结合Kast平均热容法和非线性拟合法,计算密度为1.80 g/cm 3的RDX和密度为1.14 g/cm 3的硝基甲烷的爆轰参数和爆轰产物组成,计算过程由自编程序完成。计算结果显示,非线性拟合法比Kast平均热容法计算的爆轰参数值更接近实验值;非线性拟合法计算RDX的爆温、爆压和爆速与实验值的误差分别为3.3%、0.4%和0.3%。

Least squares method was used to establish nonlinear fitting equations about thermodynamic data of detonation products.In order to verify the accuracy of these equations,Kast average heat capacity and nonlinear fitting equations were applied to calculate the enthalpy change(H T-H 298).Compared with the theoretical value,Results show that the maximum error of nonlinear fitting equations is 0.5%,the minimum and the maximum error of Kast average heat capacity are 3.1%and 12.5%,respectively.In order to accomplish the programming calculation of detonation parameters and verify the feasibility of nonlinear fitting equations,BKW equation of state was selected as the equation of state for detonation products,the principle of minimum free energy and the equation of Hugoniot were utilized,Kast average heat capacity and nonlinear fitting equations were used to obtain detonation temperature,respectively.Detonation parameters of RDX and nitromethane were calculated by self-made program,where the density of RDX is 1.80 g/cm 3,the density of nitromethane is 1.14 g/cm 3.Calculation results show that detonation parameters calculated by the nonlinear fitting equations are more close to the experimental values than Kast average heat capacity.The error of detonation temperature,pressure and velocity of RDX for nonlinear fitting equations is 3.3%,0.4%and 0.3%,respectively.