The numerical method for analysing the transient temperature field and transient phase transformation of metal materials in heat treating

In this paper,the Kirchhoffs transformation is popularized to the nonlinear heat conduction problem which the heat conductivity can be expressd as a multinomial of temperature firstly,the boundary condition of heat conduction problem is determined by analytics.Secondly,the incubation peroid superposition and the linear combination law is employed to simulate the transient phasses transformation in the process of heat treatment of materials.That the begin time of phase transformation,the type of phase transformation and the amount of phase constitution is determined simply.Finally,the three-dimension Dual Reciprocity Boundary Element Method is usedto analysis the total process of various heat treatment of component,the results of numerical calculation of examples show that the method provided in this paper is effectivce.     

金属材料热处理过程中的瞬态温度场与解态相变的数值计算方法

本文首先将Kirchhoff变换推广到导热系数为温度的多项式的非定常非线性热传导问题.并用分析方法确定热传导问题的边界条件.其次提出以孕育期叠加法并引用线性混合法则来模拟金属热处理过程的多相瞬态相变,较为简便地确定相变的开始时间、相变的种类及相变组织的数量.最后利用三维双重边界元法分析工件多种形式的热处理全过程.算例的数值计算结果表明本文方法行之有效.     

NEGRETTI采样头切割原理的动力学分析

根据两相流体动力学理论对Negretti采样头中颗粒物的运动规律进行了分析,计算了PM10和 PM2．5采样时颗粒物的运动轨迹,通过计算讨论了气流流量、颗粒物粒径等不同情况下各种因素对颗粒物运动轨迹的影响．结果表明两相流动力学是对采样切割器中颗粒物的运动进行数值模拟的有效工具,能对采样头的设计、制造提供有力的帮助．