[请教]一个潜热应该如何在ansys中应用的问题

woodcopper

相变潜热得考虑方法很多，bbs上得帖子关于理论得讨论已经很详细了，我现在有一个困惑就是潜热如何应用在ansys中。

我的思路如下：

方法：等效比热法：help中也有类似得例子：
就是潜热等效比热C0＋原有比热C
那么，我应该如何在ansys中应用呢？
我得用法如下（假设相变温度为1400度～1420度）：
MPTEMP
MPTEMP,1,200,400,600,800
MPDATA,C,1,1,10,20,30,40,         ！这是原有得比热定义


MPTEMP
MPTEMP,1,200,400,600,800,1399,1400,
MPTEMP,7,1420,1421
MPDATA,C,1,1,10,20,30,40, 40，40（原比热C）+20000（等效比热C0）       ！这是我考虑了融化潜热得定义
MPDATA,C,1,7,20040，40

问题一：这种方法对吗？
问题二：基于问题一正确的基础上，我们知道比热得采用是基于上次计算温度场得判断，如果上次某点得温度是1350度，那么他采用得就是该温度下得C，那么如果使用这个C值进行下次计算，得出的温度是1500度了，那么他将用1500度判断C，那么这个额外的差值就没用了

总结一下：潜热该如何这确定义是应用的要领，对于新手而言理论估计大家都清楚，但是如何使用还是一个问题，
所以针对我得困惑，恳请知道得大侠们指点一下，也请版主不吝赐教！
bowing

woodcopper

help是用潜热来计算得，貌似不太适合焊接相变，不知道对否！

woodcopper

顶一下，斑竹来看看啊

woodcopper

怎么没人出来解释一下啊

iomega

For simulation involving latent heat, you can use two approaches:
(1) define the temperature dependent enthalpy (J/m^3). The slope of enthalpy at given temperature should be equal to the specific heat (J/m^3-K) at that temperature. While the difference of enthalpy at the phase change region temperatures should be set as the value of latent heat.

(2) use temperature dependent specific heat. The area of specific heat * temperature should be the same as latent heat.

woodcopper

For simulation involving latent heat, you can use two approaches:
(1) define the temperature dependent enthalpy (J/m^3). The slope of enthalpy at given temperature should be equal to the specific heat (J/m^3-K) at that temperature. While the difference of enthalpy at the phase change region temperatures should be set as the value of latent heat.

(2) use temperature dependent specific heat. The area of specific heat * temperature should be the same as latent heat.

I got it, but how to deal with the unconvergence problem. well, it is easily unconvergent while the latent heat was took into account, PLS tell me what parameters should be set?