摘要
分析了时域无条件稳定算法加速计算的原理和由此造成误差的原因 ,提出并用实验验证了判断步内建模法( MPWT)模拟的瞬态热过程正确性的“终态 -起始段 -过程曲线稳定性”的快捷方法 .模拟的瞬态过程如正确则必须满足 :( 1)终态的热斑温度正确、热场形貌合理 ;( 2 )瞬态过程的起始段正确 ;( 3 )在一定范围内改变计算参数模拟的瞬态过程曲线基本不改变 ,即模拟的瞬态过程曲线有稳定性 .MESFET的实例说明 ,如果模拟的瞬态能通过这些检查 ,它就与实验有较好的一致性 .用
A quick routine called 'ending point-initial st ag e-curve shape stability' check is proposed for MPWT(modelling the diffusion pr ocesses within the time step).According to this check routine,conditions for a c orrect simulated transient must include:(1) The hot spot temperature and morpho logy of ending field of the transient need to be very close to that of the simul ated steady thermal field whose accuracy is guaranteed by the check rules propos ed by author;(2) The transient temperature of hot spot up to 5%～10% of its stea dy value has to be very close to that calculated by finite difference (FD);(3) S imulated transient curve shape should change very little when the parameters,suc h as initial time step and step increasing factor,change in some extent.An examp le of MESFET shows that once the simulated transient passes these checks,the sim ulation will have good agreement with experiment.The time for a MPWT simulation and relevant checks is only a few percent of that cost by finite difference me thod.
基金
国家自然科学基金资助项目 (批准号 :698760 2 9)~~
