CST stability factor for timestep

CST 的special solver parameters里有個(gè)stability factor for timestep，這個(gè)參數(shù)默認(rèn)是1，有時(shí)候仿真后會(huì)出現(xiàn)不穩(wěn)定的提示，軟件建議降低此系數(shù)……不知降低后對(duì)結(jié)果的準(zhǔn)確性有多大程度的影響？這個(gè)參數(shù)的具體指什么呢……

stability factor for timestep可能是時(shí)間步長(zhǎng)和空間步長(zhǎng)的比值。通常這個(gè)比值大，仿真速度快，但可能導(dǎo)致不穩(wěn)定解。降低這個(gè)比值，仿真速度會(huì)慢些，但可以得到穩(wěn)定的解。

明白了
這么解釋的：a stability factor that will be multiplied to the current valid stability limit for the numerical timestep. In case that a time domain calculation shows some slight effects of instability, a small reduction of the stability factor might recover a stable state. Note: Choosing a factor greater than one is not advisable and will likely produce instability.

計(jì)算過(guò)程中，出現(xiàn)計(jì)算不穩(wěn)定時(shí)，把stability factor for timestep的值由1變?yōu)?.95時(shí)。計(jì)算就穩(wěn)定了。

時(shí)間步長(zhǎng)因子越小，意味著需要更多的迭代，計(jì)算兩就越大。求解時(shí)間就是你要分析的物理過(guò)程經(jīng)歷的真實(shí)時(shí)間。