我每天一般能接到1~5位同行通过邮件问我有关火灾模拟的问题,说明如下:
(1)不要问基础问题
比如、如何设置排烟口、喷淋具体设置哪些参数等。
(2)问问题时附上你的模型文件
比如问:我的模型中,沙发不着火是怎么回事。原因太多了:初始火源太小、沙发没设置热解参数、参数设置不合理。明显没有看到模型,怎么知道什么原因。
(3)不要要求我加微信或者加入某个群
我有自己的工作,业余时间回答问题,不能成为秘书。
(4)数值不稳定就不要问了,这是CFD的共性问题,不只是火灾模拟。FDS手册列举了一下原因:
• mesh cells that have an aspect ratio larger than 2 to 1
• high speed flow through a small opening• a sudden change in the heat release rate
• the removal or creation of an obstruction, like the opening or closing of a door
• a high (>100 g/mol) molecular weight fuel molecule that is not in the FDS database, Table 14.1.In such cases, reduce the molecular weight but maintain the atom ratios.
• long, sealed tunnels, in which pressure fluctuations can cause spurious numerical artifacts. SeeSection 9 for details.
There are various ways to solve the problem, depending on the situation. Try to diagnose and fix theproblem before reporting it. It is difficult for anyone but the originator of the input file to diagnose theproblem.
自己对照一下,违反那一条了。当然都不违反也可能出现,只有上帝知道原因。
我的经验是,逐渐删除一些东西,运行试试。通过很长时间就能解决问题了。我自己的一个模型,过了一年才发现问题。很明显,我不可能给你一点一点试。
(1)不要问基础问题
比如、如何设置排烟口、喷淋具体设置哪些参数等。
(2)问问题时附上你的模型文件
比如问:我的模型中,沙发不着火是怎么回事。原因太多了:初始火源太小、沙发没设置热解参数、参数设置不合理。明显没有看到模型,怎么知道什么原因。
(3)不要要求我加微信或者加入某个群
我有自己的工作,业余时间回答问题,不能成为秘书。
(4)数值不稳定就不要问了,这是CFD的共性问题,不只是火灾模拟。FDS手册列举了一下原因:
• mesh cells that have an aspect ratio larger than 2 to 1
• high speed flow through a small opening• a sudden change in the heat release rate
• the removal or creation of an obstruction, like the opening or closing of a door
• a high (>100 g/mol) molecular weight fuel molecule that is not in the FDS database, Table 14.1.In such cases, reduce the molecular weight but maintain the atom ratios.
• long, sealed tunnels, in which pressure fluctuations can cause spurious numerical artifacts. SeeSection 9 for details.
There are various ways to solve the problem, depending on the situation. Try to diagnose and fix theproblem before reporting it. It is difficult for anyone but the originator of the input file to diagnose theproblem.
自己对照一下,违反那一条了。当然都不违反也可能出现,只有上帝知道原因。
我的经验是,逐渐删除一些东西,运行试试。通过很长时间就能解决问题了。我自己的一个模型,过了一年才发现问题。很明显,我不可能给你一点一点试。