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请教大神们一个Fluent熔化凝固模型的问题。
我想模拟双组分混合物的熔融结晶过程，结晶器如下图所示，沿Y轴方向有刺状的几何结构。
ede3d4b9-b703-46b3-aa83-fb3cca6a0882-07c9f6ef64fb637240d2932931629a6.png
在模拟过程中考虑了重力影响（-Y），开启了层流，能量，组分输运，熔化凝固模型，混合物含量是7wt%A和93wt%B，纯A的熔点是35℃，纯B的熔点是21℃，低共熔温度-10℃；冷却壁面温度设置为14℃，无滑移；顶面和底面为无滑移绝热壁面；初始化温度为25℃；计算方法设置如下：

计算结束后，XY平面的液相体积分数分布如下：
20824d3d-7bba-4db9-b635-44673ff6ce00-cb154dc97a13ac27218b6dba8a40798.png
实验结果发现，在刺状的部分生成了较多的冷凝物，但计算结果显示凝固的物质沿壁面均匀分布，跟实验结果差距挺大，想请教一下各位大神该如何改进

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@李东岳好的，谢谢李老师！

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@李东岳，李老师，《多相流及群体平衡模型的数值计算方法》这本书在哪里可以下载或者买到呢？我看到了19年5月的一版PDF，还有很多地方未完成。但找遍各个地方都没找到，特来询问您一下。感谢！

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各位大佬，求帮忙看一下计算出错的原因。
我模拟一个结晶的过程，在PBE模型中挂上成核与生长的UDF时，计算一开始就出现了报错，不挂UDF就可以正常计算下去。报错时控制台的提示信息如下：

Initialize using the hybrid initialization method.

Checking case topology... 
-This case has both inlets & outlets 
-Pressure information is not available at the boundaries.
 Case will be initialized with constant pressure

	iter		scalar-0

	1		1.000000e+00
	2		1.145484e-05
	3		8.608675e-07
	4		2.028824e-07
	5		2.753174e-08
	6		5.988739e-09
	7		9.756630e-10
	8		2.840014e-10
	9		5.402100e-11
	10		1.498808e-11

Hybrid initialization is done.

Creating new file G:\.\mass_frac_z=0-rfile_1_1.out
Creating new file G:\.\mass_frac_z=-40-rfile_1_1.out
Creating new file G:\.\mass_frac_z=5-rfile_1_1.out

  iter  continuity  u-solution   u-crystal  v-solution   v-crystal  w-solution   w-crystal   energy-p1   energy-p2           k     epsilon  paracetamo  water-solu  bf-0-cryst  bf-1-cryst  bf-2-cryst  bf-3-cryst  bf-4-cryst  bf-5-cryst  bf-6-cryst  bf-7-cryst  bf-8-cryst  bf-9-cryst  bf-10-crys  bf-11-crys  bf-12-crys  bf-13-crys  bf-14-crys  vf-crystal     time/iter
 temperature limited to 1.000000e+00 in 1345882 cells on zone 8407 in domain 2
      1  1.0000e+00  6.0854e-04  0.0000e+00  6.0847e-04  0.0000e+00  9.3036e-04  0.0000e+00  8.2651e-03  0.0000e+00  7.5450e-02  1.6778e-01  1.7762e+00  1.6993e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0.0000e+00  0:00:31    1


Error at Node 0: floating point exception

Error at Node 1: floating point exception

Error at Node 2: floating point exception
Error at Node 3: floating point exception

Error at Node 4: floating point exception

Error at Node 5: floating point exception

Error at Node 6: floating point exception

Error at Node 7: floating point exception

Error at Node 8: floating point exception

Error at Node 9: floating point exception

Error at Node 10: floating point exception

Error at Node 11: floating point exception

Error at 
Error at Node 13: floating point exception

Error at Node 15: floating point exception
N
Error at Node 14: floating point exception
ode 12: floating point exception

Experiencing convergence difficulties - temporarily relaxing and trying again...

Experiencing convergence difficulties - temporarily relaxing and trying again...

Experiencing convergence difficulties - temporarily relaxing and trying again...

Experiencing convergence difficulties - temporarily relaxing and trying again...
        Stabilizing pressure coupled to enhance linear solver robustness.
        Stabilizing pressure coupled using GMRES to enhance linear solver robustness.

Experiencing convergence difficulties - temporarily relaxing and trying again...

Divergence detected in AMG solver: pressure coupled        Stabilizing solution-species-0 to enhance linear solver robustness.
        Stabilizing solution-species-0 using GMRES to enhance linear solver robustness.

Divergence detected in AMG solver: solution-species-0        Stabilizing solution-species-1 to enhance linear solver robustness.
        Stabilizing solution-species-1 using GMRES to enhance linear solver robustness.

Divergence detected in AMG solver: solution-species-1 temperature limited to 1.000000e+00 in 273407 cells on zone 8407 in domain 2
         Stabilizing vof-1 to enhance linear solver robustness.
        Stabilizing vof-1 using GMRES to enhance linear solver robustness.

Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Divergence detected in AMG solver: pressure coupled
Divergence detected in AMG solver: solution-species-0
Divergence detected in AMG solver: solution-species-1
Divergence detected in AMG solver: vof-1
Error at host: floating point exception

Error: floating point exception
Error Object: #f

应该是UDF的问题，但不知道具体是什么问题。生长速率udf代码如下：

#include "sg_mphase.h"
DEFINE_PB_GROWTH_RATE(growth_rate,cell,thread,d_1)
{
	real G;/* growth rate in m/s*/
	real Kg = 1.280e-5; /* growth rate constant */
	real g = 1.947;/* primary nucleation law power index */
	real x;/* the antisolvent proportion in kg-antisolvent/kg-antisolvent and solvent */
	real y;/* the solubility in kg-solute/kg-antisolvent and solvent */
	real C;/* the solute concentration in kg-solute/kg-solvent */
	real Solubility;/* the solubility in kg-solute/kg-solvent */
	real delta_C;/* the difference between the solute concentration and the solubility, kg-solute/kg-solvent */
	real solute_mass_frac,solvent_mass_frac,antisolvent_mass_frac;

	Thread *tc = THREAD_SUPER_THREAD(thread); /* obtain mixture thread */
	Thread **pt = THREAD_SUB_THREADS(tc); /* pointer to sub_threads */
	Thread *tp = pt[P_PHASE]; /* primary phase thread */

	solute_mass_frac = C_YI(cell,tp,0);/* mass fraction of solute in primary phase (solvent,antisolvent,Paracetamol) */
	solvent_mass_frac = C_YI(cell,tp,2);/* mass fraction of solvent in primary phase (solvent,antisolvent,Paracetamol ) */
	antisolvent_mass_frac = 1.-solute_mass_frac-solvent_mass_frac;/* mass fraction of antisolvent in primary phase (solvent,antisolvent,Paracetamol) */

	x = antisolvent_mass_frac/(antisolvent_mass_frac+solvent_mass_frac);/* the antisolvent proportion in kg-antisolvent/kg-antisolvent and solvent */
	y = -2.63748*pow(x,4)+9.04654*pow(x,3)-10.86277*pow(x,2)+5.04399*x-0.57920;/* the solubility in kg-solute/kg-antisolvent and solvent */
	Solubility = y*(1.+(antisolvent_mass_frac /solvent_mass_frac));/* the solubility in kg-solute/kg-solvent */
	C = solute_mass_frac/solvent_mass_frac;/* the solute concentration in kg-solute/kg-solvent */
	delta_C = C-Solubility; /* Definition of Supersaturation */

	if (delta_C == 0.)
	{
		G = 0.;
	}
	else
	{
		G = Kg*pow(delta_C,g);
	}
	return G;
}

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@bestucan
在开始里面搜commander是这个吗

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@lee459317530
请问为什么要将Thread **pt = THREAD_SUB_THREADS(tc);改成Thread *pt = THREAD_SUB_THREADS(thread); 呢？
我使用Thread **pt = THREAD_SUB_THREADS(tc);的时候就显示“生成成功”了

但还是有之前同样的问题

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@bestucan 多谢多谢！

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各位大佬好，最近在PBM模型中要写入一个关于成核的UDF，按照教程中的示例做了修改，然后再fluent中编译时出现了问题，麻烦各位大佬看看时怎么了

代码如下：

/************************************************************************
           UDF that computes the particle nucleation rate
*************************************************************************/
#include "udf.h"
#include "sg_pb.h"
#include "sg_mphase.h"
DEFINE_PB_NUCLEATION_RATE(nuc_rate, cell, thread)
{
real B;/* nucleation rate in #/(s kg-solvent)*/
real Kb_1 = 4.355; /* primary nucleation rate constant */
real Kb_2 = 3.968e14;/* secondary nucleation rate constant */
real b_1  = 1.852;/* primary nucleation law power index */
real b_2  = 4.226;/* secondary nucleation law power index */
real x;/*the antisolvent proportion in kg- antisolvent/kg-antisolvent and solvent */
real y;/*the solubility in kg-solute/kg- antisolvent and solvent */
real C;/*the solute concentration in kg-solute/kg-solvent*/
real Solubility;/*the solubility in kg-solute/kg-solvent */
real delta_C;/*the difference between the solute concentration and the solubility, kg-solute/kg-solvent*/
real solute_mass_frac,solvent_mass_frac,antisolvent_mass_frac;
real m;

Thread *tc = THREAD_SUPER_THREAD(thread); /*obtain mixture thread */
Thread **pt = THREAD_SUB_THREADS(tc); /* pointer to sub_threads */
Thread *tp = pt[P_PHASE]; /* primary phase thread */

solute_mass_frac = C_YI(cell,tp,0);/*mass fraction of solute in primary phase (solvent,antisolvent,Paracetamol)*/
solvent_mass_frac = C_YI(cell,tp,1);/* mass fraction of solvent in primary phase (solvent,antisolvent,Paracetamol ) */
antisolvent_mass_frac = 1-solute_mass_frac-solvent_mass_frac;/* mass fraction of antisolvent in primary phase (solvent,antisolvent,Paracetamol)*/

x=antisolvent_mass_frac/(antisolvent_mass_frac+solvent_mass_frac);/*the antisolvent proportion in kg- antisolvent/kg-antisolvent and solvent */
y =-2.63748*pow(x,4)+9.04654*pow(x,3)-10.86277*pow(x,2)+5.04399*x-0.57920;/*the solubility in kg-solute/kg- antisolvent and solvent */
Solubility=y*(1+(antisolvent_mass_frac/solvent_mass_frac));/*the solubility in kg-solute/kg- solvent */
C=solute_mass_frac/solvent_mass_frac;/*the solute concentration in kg-solute/kg- solvent*/
delta_C = C-Solubility; /* Definition of Supersaturation */
m=C_VOF(cell,pt[1])*1293;

if (delta_C == 0.)
{
B = 0.;
}
else
{
B = (Kb_1)*pow(delta_C,b_1)+(Kb_2)*pow(delta_C,b_2)*m;
}
return B;
}

Build的时候提示是这样的

然后点击Load的提示是这样的

编程功力不太行，只能按照示例在上面修改，很多地方不太懂，还请各位大佬帮忙看看，这究竟是咋回事呢？@东岳

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刚刚接触PBE与有限体积法相关的东西，入门起来比较吃力，希望得到指点，感谢
最近看到一篇使用HR算法求解PBE的文献，文献中对算法的介绍和对PBE的离散过程如下：

文中写出的PBE形式为

离散后得到如下形式：

!

我不是很理解如何离散的，看不懂这个过程，比如公式6中的a代表什么，minmod limiter又是什么东东？公式11,12又是怎么来的等等，感觉自己脑子都浆糊了，小白希望得到李老师的解答

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有点明白了，我再好好看看李老师的论文，谢谢！

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最近刚刚接触PBE的方向，看过一些文献后，发现关于PBE有几种形式的写法，想问问论坛的大佬如何理解这些形式，有什么区别，又如何统一呢？感谢！
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