通过VOF和solidification模型仿真液滴结冰，有没有大佬实现过体积膨胀？

就是这个扩散通量的正负。一般扩散项到等号左边是付的。

可以相信这一家：https://www.phoronix.com/review/amd-ryzen9-7950x3d-linux/

@Yan 您好，请问您是用的什么后处理软件，在导出速度的时候可以把笛卡尔坐标系改成柱坐标系

求助各位老师，在扩展出口计算域计算时，发现了如下问题，具体细节如下图，不同方案中红色截面处的总压大小不同，是什么原因造成的。（尤其是方案2和方案3总压的不同是因为什么原因）
问.png

有没有大佬做过电解碱水制氢的算例模拟啊，帮助文档里的电解水制氢复现了，点解碱水大佬们有没有做成功的case文件

请问一下各位大佬，欧拉-欧拉气固两相流模拟，设置流体域旋转后，wall可以设置成不旋转吗，对结果有没有影响，因为wall设置成旋转之后，就无法设置镜面反射系数了

@吴优 现在的问题是如何将我的我的结构求解模块和fluent联立起来。是如何获取wall的表面力用于插值到固体域网格。

我觉得不能。RANS大部分都抹掉了。
有大佬看到系统的论述么？

各位CFD大佬，小弟最近在用fluent做模拟时遇到一个问题，物理背景就是管内的热水以射流的方式喷出然后被周围的环境冷水稀释，在做小模型模拟（x=40m y=2m z=13.3cm）的时候，模拟结果尚可，对称性很完美，但在做大模型的时候（x=4000m y=2000m z=10m）,模拟结果很不好。
用的稳态模拟，大模型网格数量大概七百多万，用的reliazable k-e湍流模型，进口的湍流参数设置用CFD计算器估算过了，另外在模拟的时候fluent一直有湍流粘度比超限的提示，但小模型就不会有，不知道最后的不对称结果和这个是不是有关系。
1564dc71-8ed2-4905-ba1b-67fbca1936e3-图片.png
热水从圆的四周均匀喷射出来，然后被流动的冷水稀释，冷水流动方向从左至右，可以看到图中并没有达到一个对称效果，等值线都没有对称。
21f863e0-2b3c-4e9f-994a-ae3797889acf-图片.png
热水进口在上图的最底部，垂直向上喷射，中间比较黑的那一块有一块顶盖，作用是让热水向周围扩散开来而不是垂直向上冲，图中看到网格有些瑕疵的地方是tecplot的显示问题，可以忽略。
a652dbd8-6ce0-4c30-9c4a-97e6fee8e965-892fea64760b5fcdfe9299ba371783e.png
从这张图可以看出热水向上喷射，被顶盖挡住，最后向四周扩散上浮的过程。

总结一下几点疑问：
1.模拟时fluent的湍流粘度比超限警告是否和最后模拟结果的不对称有关系？
2.小模型模拟结果对称，而大模型就不行，和网格的大小有关系吗？小模型的最大网格大概也就在厘米级别，而大模型的最大网格一般在米级别（最大有五米左右）。
其实最核心的诉求还是想解决对称性的问题，最好不要用对称边界条件，能用整个模型就用整个模型。

对称几何对称网格对称边界条件，但最后模拟出来的结果不对称的问题。

这个问题是会有发生，就类似圆柱扰流，注定是不对称的。不过如果是一个可以对称的物理，加上一个完全对称的数值设置。发生不对称的结果。就不太好说了。

采用overset重叠网格和UDF函数模拟串列三圆柱的涡激振动，其中UDF分别尝试了Newmark-Beta方法和4阶Runge Kutta法获取圆柱的振动响应，通过DEFINE_CG_MOTION宏赋予三个圆柱及component cells的运动速度，算例的雷诺数约200，采用k-omega sst模型，考虑水作为来流介质，计算过程中尝试了时间步长从1.0e-3缩小到1.0e-5等多个量级，但是求解过程总是出现升力和升力矩突然骤增，继而导致圆柱运动速度过大，最终计算发散。

请各位大佬帮忙看看是哪里出问题？

具体的UDF和部分设置如下：

#include "udf.h" #include "sg_mem.h" #include "dynamesh_tools.h" #define PI 3.141592654 #define zoneID_1 4 #define zoneID_2 16 #define zoneID_3 20 FILE *outNB,*outRK; static real y = 0.0; static real yRK = 0.0; static real dy = 0.0; static real vy = 0.0; static real vyRK = 0.0; static real vyRK2 = 0.0; static real ay = 0.0; static real current_time = 5; static real y2 = 0.0; static real y2RK = 0.0; static real dy2 = 0.0; static real vy2 = 0.0; static real vy2RK = 0.0; static real vy2RK2 = 0.0; static real ay2 = 0.0; static real current_time2 = 5; static real y3 = 0.0; static real y3RK = 0.0; static real dy3 = 0.0; static real vy3 = 0.0; static real vy3RK = 0.0; static real vy3RK2 = 0.0; static real ay3 = 0.0; static real current_time3 = 5; DEFINE_CG_MOTION(cylinder_1,dt,vel,omega,time,dtime) { real ctime = RP_Get_Real("flow-time"); real ctimestep = RP_Get_Integer("time-step"); real niter = N_ITER; if (current_time < ctimestep) { current_time = ctimestep; /*Define variables*/ /*Mesh variables*/ real cg[3],vcg[3]; /*Cylinder variables*/ real diameter = 0.063; real fn = 1.0892; real density = 998.2; real length = 1; real water_depth = 1; real mass_ratio = 0.3937; real damping_ratio = 0.01; real mass = mass_ratio*density*pow((0.5*diameter),2)*PI*length; real ad_mass = mass*(0); /*density*pow((0.5*diameter),2)*PI*water_depth;*/ real total_mass = mass + ad_mass; real k = 4*pow((PI*fn),2)*total_mass; real c = 2 * damping_ratio * sqrt(k*total_mass); /*Force calculation. Force = F_pressure + F_viscous*/ real fy = 0.0; real fvy = 0.0; int i; #if !RP_HOST Thread *tc,*thread; Domain *d = Get_Domain(1); face_t f; tc = Lookup_Thread(d,zoneID_1); thread = DT_THREAD(dt); NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); real NV_VEC(A); begin_f_loop(f,tc) { if (PRINCIPAL_FACE_P(f,tc)) { fvy = F_STORAGE_R_N3V(f,tc,SV_WALL_SHEAR)[1]*-1; /*“*-1”表示方向*/ F_AREA(A,f,tc); /*Force calculation with a depth of 1m*/ fy += F_P(f,tc)*A[1] + fvy; } } end_f_loop(f,tc) #endif #if RP_NODE fy = PRF_GRSUM1(fy); #endif /*Dynamic mesh position*/ #if!RP_HOST for (i=0;i<3;i++) { cg[i]=DT_CG(dt)[i]; vcg[i] = DT_VEL_CG(dt)[i]; } Message("Position CG: %f \n",cg[1]); #endif node_to_host_real_2(fy,cg[1]); /*Numerical methods*/ /*Numark-beta*/ real beta = 0.25; real gamma = 0.5; real term0 = (1/(beta*dtime*dtime))*(mass+ad_mass) + (gamma/(beta*dtime))*c; real term1 = (1/(beta*dtime))*(mass+ad_mass) + ((gamma/beta)-1)*c; real term2 = ((1/(2*beta))-1)*(mass+ad_mass) + dtime*((gamma/(2*beta))-1)*c; real Keff = k + term0; real Reff = fy*water_depth + term0*cg[1] + term1*vy + term2*ay; Message("Velocity: %f \n",vy); dy = Reff/Keff - cg[1]; y += dy; real vprev = vy; vy = (gamma/(beta*dtime))*dy + (1-(gamma/beta))*vy + dtime*(1-(gamma/(2*beta)))*ay; ay = (1/(beta*dtime*dtime))*dy - (1/(beta*dtime))*vprev - ((1/(2*beta))-1)*ay; /*Runge-kutta 4th order*/ real K1 = (fy*water_depth - c*vyRK - k*yRK) / total_mass; real K2 = (fy*water_depth - c*(vyRK+dtime*0.5*K1) - k*(yRK+dtime*0.5*vyRK)) / total_mass; real K3 = (fy*water_depth - c*(vyRK+dtime*0.5*K2) - k*(yRK+dtime*0.5*vyRK+dtime*dtime*K1/4)) / total_mass; real K4 = (fy*water_depth - c*(vyRK+dtime*K3) - k*(yRK+dtime*vyRK+dtime*dtime*K1/2)) / total_mass; yRK = yRK + vyRK*dtime + dtime*dtime*(K1 + K2 + K3 + K4)/6; vyRK = vyRK + dtime*(K1 + K2 + K3 + K4)/6; /*Transfer result to the dynamic mesh*/ vel[0] = 0.0; vel[1] = vyRK; /*Save files*/ #if !RP_NODE /*Message ("Force = %f, pos = %f, vel = %f, acc = %f\n", fy, cg[1], y, vy);*/ if(NULL == (outNB = fopen("dataNB1.txt","a"))) { Error("Could not open file for append!\n"); } fprintf(outNB,"%16.4e %12.1f %16.3e %16.7f %16.7f %16.7f \n", ctime,niter, fy , cg[1], y, vy); fclose(outNB); if(NULL == (outRK = fopen("dataRK1.txt","a"))) { Error("Could not open file for append!\n"); } fprintf(outRK,"%16.4e %12.1f %16.3e %16.7f %16.7f %16.7f \n", ctime,niter, fy , cg[1], yRK, vyRK); fclose(outRK); #endif } /*Transfer result to the dynamic mesh*/ vel[0] = 0.0; vel[1] = vyRK; } DEFINE_CG_MOTION(cylinder_1_frontgrid_1,dt,vel,omega,time,dtime) { NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); vel[0]=0.0; vel[1]=vyRK; } DEFINE_CG_MOTION(cylinder_1_overset_2,dt,vel,omega,time,dtime) { NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); vel[0]=0.0; vel[1]=vyRK; } DEFINE_ZONE_MOTION(cylinder_1_zone,omega,axis,origin,velocity,time,dtime) { N3V_D(velocity, =, 0, 0, 0); N3V_S(origin, =, -0.32); N3V_D(axis, =, 0.0, 0.0, 1.0); velocity[1]=vyRK; } DEFINE_CG_MOTION(cylinder_2,dt,vel,omega,time,dtime) { real ctime = RP_Get_Real("flow-time"); real ctimestep = RP_Get_Integer("time-step"); real niter = N_ITER; if (current_time2 < ctimestep) { current_time2 = ctimestep; /*Define variables*/ /*Mesh variables*/ real cg[3],vcg[3]; /*Cylinder variables*/ real diameter = 0.063; real fn = 1.0892; real density = 998.2; real length = 1; real water_depth = 1; real mass_ratio = 0.3937; real damping_ratio = 0.01; real mass = mass_ratio*density*pow((0.5*diameter),2)*PI*length; real ad_mass = mass*(0); /*density*pow((0.5*diameter),2)*PI*water_depth;*/ real total_mass = mass + ad_mass; real k = 4*pow((PI*fn),2)*total_mass; real c = 2 * damping_ratio * sqrt(k*total_mass); /*Force calculation. Force = F_pressure + F_viscous*/ real fy = 0.0; real fvy = 0.0; int i; #if !RP_HOST Thread *tc,*thread; Domain *d = Get_Domain(1); face_t f; tc = Lookup_Thread(d,zoneID_2); thread = DT_THREAD(dt); NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); real NV_VEC(A); begin_f_loop(f,tc) { if (PRINCIPAL_FACE_P(f,tc)) { fvy = F_STORAGE_R_N3V(f,tc,SV_WALL_SHEAR)[1]*-1; /*“*-1”表示方向*/ F_AREA(A,f,tc); /*Force calculation with a depth of 1m*/ fy += F_P(f,tc)*A[1] + fvy; } } end_f_loop(f,tc) #endif #if RP_NODE fy = PRF_GRSUM1(fy); #endif /*Dynamic mesh position*/ #if!RP_HOST for (i=0;i<3;i++) { cg[i]=DT_CG(dt)[i]; vcg[i] = DT_VEL_CG(dt)[i]; } Message("Position CG: %f \n",cg[1]); #endif node_to_host_real_2(fy,cg[1]); /*Numerical methods*/ /*Numark-beta*/ real beta = 0.25; real gamma = 0.5; real term0 = (1/(beta*dtime*dtime))*(mass+ad_mass) + (gamma/(beta*dtime))*c; real term1 = (1/(beta*dtime))*(mass+ad_mass) + ((gamma/beta)-1)*c; real term2 = ((1/(2*beta))-1)*(mass+ad_mass) + dtime*((gamma/(2*beta))-1)*c; real Keff = k + term0; real Reff = fy*water_depth + term0*cg[1] + term1*vy2 + term2*ay2; Message("Velocity: %f \n",vy2); dy2 = Reff/Keff - cg[1]; y2 += dy2; real vprev = vy2; vy2 = (gamma/(beta*dtime))*dy2 + (1-(gamma/beta))*vy2 + dtime*(1-(gamma/(2*beta)))*ay2; ay2 = (1/(beta*dtime*dtime))*dy2 - (1/(beta*dtime))*vprev - ((1/(2*beta))-1)*ay2; /*Runge-kutta 4th order*/ real K1 = (fy*water_depth - c*vy2RK - k*yRK) / total_mass; real K2 = (fy*water_depth - c*(vy2RK+dtime*0.5*K1) - k*(y2RK+dtime*0.5*vy2RK)) / total_mass; real K3 = (fy*water_depth - c*(vy2RK+dtime*0.5*K2) - k*(y2RK+dtime*0.5*vy2RK+dtime*dtime*K1/4)) / total_mass; real K4 = (fy*water_depth - c*(vy2RK+dtime*K3) - k*(y2RK+dtime*vy2RK+dtime*dtime*K1/2)) / total_mass; y2RK = y2RK + vy2RK*dtime + dtime*dtime*(K1 + K2 + K3 + K4)/6; vy2RK = vy2RK + dtime*(K1 + K2 + K3 + K4)/6; /*Transfer result to the dynamic mesh*/ vel[0] = 0.0; vel[1] = vy2RK; /*Save files*/ #if !RP_NODE /*Message ("Force = %f, pos = %f, vel = %f, acc = %f\n", fy, cg[1], y, vy);*/ if(NULL == (outNB = fopen("dataNB2.txt","a"))) { Error("Could not open file for append!\n"); } fprintf(outNB,"%16.4e %12.1f %16.3e %16.7f %16.7f %16.7f \n", ctime,niter, fy , cg[1], y2, vy2); fclose(outNB); if(NULL == (outRK = fopen("dataRK2.txt","a"))) { Error("Could not open file for append!\n"); } fprintf(outRK,"%16.4e %12.1f %16.3e %16.7f %16.7f %16.7f \n", ctime,niter, fy , cg[1], y2RK, vy2RK); fclose(outRK); #endif } /*Transfer result to the dynamic mesh*/ vel[0] = 0.0; vel[1] = vy2RK; } DEFINE_CG_MOTION(cylinder_2_frontgrid_1,dt,vel,omega,time,dtime) { NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); vel[0]=0.0; vel[1]=vy2RK; } DEFINE_CG_MOTION(cylinder_2_overset_2,dt,vel,omega,time,dtime) { NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); vel[0]=0.0; vel[1]=vy2RK; } DEFINE_ZONE_MOTION(cylinder_2_zone,omega,axis,origin,velocity,time,dtime) { N3V_D(velocity, =, 0, 0, 0); N3V_S(origin, =, 0.0); N3V_D(axis, =, 0.0, 0.0, 1.0); velocity[1]=vy2RK; } DEFINE_CG_MOTION(cylinder_3,dt,vel,omega,time,dtime) { real ctime = RP_Get_Real("flow-time"); real ctimestep = RP_Get_Integer("time-step"); real niter = N_ITER; if (current_time3 < ctimestep) { current_time3 = ctimestep; /*Define variables*/ /*Mesh variables*/ real cg[3],vcg[3]; /*Cylinder variables*/ real diameter = 0.063; real fn = 1.0892; real density = 998.2; real length = 1; real water_depth = 1; real mass_ratio = 0.3937; real damping_ratio = 0.01; real mass = mass_ratio*density*pow((0.5*diameter),2)*PI*length; real ad_mass = mass*(0); /*density*pow((0.5*diameter),2)*PI*water_depth;*/ real total_mass = mass + ad_mass; real k = 4*pow((PI*fn),2)*total_mass; real c = 2 * damping_ratio * sqrt(k*total_mass); /*Force calculation. Force = F_pressure + F_viscous*/ real fy = 0.0; real fvy = 0.0; int i; #if !RP_HOST Thread *tc,*thread; Domain *d = Get_Domain(1); face_t f; tc = Lookup_Thread(d,zoneID_3); thread = DT_THREAD(dt); NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); real NV_VEC(A); begin_f_loop(f,tc) { if (PRINCIPAL_FACE_P(f,tc)) { fvy = F_STORAGE_R_N3V(f,tc,SV_WALL_SHEAR)[1]*-1; /*“*-1”表示方向*/ F_AREA(A,f,tc); /*Force calculation with a depth of 1m*/ fy += F_P(f,tc)*A[1] + fvy; } } end_f_loop(f,tc) #endif #if RP_NODE fy = PRF_GRSUM1(fy); #endif /*Dynamic mesh position*/ #if!RP_HOST for (i=0;i<3;i++) { cg[i]=DT_CG(dt)[i]; vcg[i] = DT_VEL_CG(dt)[i]; } Message("Position CG: %f \n",cg[1]); #endif node_to_host_real_2(fy,cg[1]); /*Numerical methods*/ /*Numark-beta*/ real beta = 0.25; real gamma = 0.5; real term0 = (1/(beta*dtime*dtime))*(mass+ad_mass) + (gamma/(beta*dtime))*c; real term1 = (1/(beta*dtime))*(mass+ad_mass) + ((gamma/beta)-1)*c; real term2 = ((1/(2*beta))-1)*(mass+ad_mass) + dtime*((gamma/(2*beta))-1)*c; real Keff = k + term0; real Reff = fy*water_depth + term0*cg[1] + term1*vy3 + term2*ay3; Message("Velocity: %f \n",vy3); dy3 = Reff/Keff - cg[1]; y3 += dy3; real vprev = vy3; vy3 = (gamma/(beta*dtime))*dy3 + (1-(gamma/beta))*vy3 + dtime*(1-(gamma/(2*beta)))*ay3; ay3 = (1/(beta*dtime*dtime))*dy3 - (1/(beta*dtime))*vprev - ((1/(2*beta))-1)*ay3; /*Runge-kutta 4th order*/ real K1 = (fy*water_depth - c*vy3RK - k*y3RK) / total_mass; real K2 = (fy*water_depth - c*(vy3RK+dtime*0.5*K1) - k*(y3RK+dtime*0.5*vy3RK)) / total_mass; real K3 = (fy*water_depth - c*(vy3RK+dtime*0.5*K2) - k*(y3RK+dtime*0.5*vy3RK+dtime*dtime*K1/4)) / total_mass; real K4 = (fy*water_depth - c*(vy3RK+dtime*K3) - k*(y3RK+dtime*vy3RK+dtime*dtime*K1/2)) / total_mass; y3RK = y3RK + vy3RK*dtime + dtime*dtime*(K1 + K2 + K3 + K4)/6; vy3RK = vy3RK + dtime*(K1 + K2 + K3 + K4)/6; /*Transfer result to the dynamic mesh*/ vel[0] = 0.0; vel[1] = vy3RK; /*Save files*/ #if !RP_NODE /*Message ("Force = %f, pos = %f, vel = %f, acc = %f\n", fy, cg[1], y, vy);*/ if(NULL == (outNB = fopen("dataNB3.txt","a"))) { Error("Could not open file for append!\n"); } fprintf(outNB,"%16.4e %12.1f %16.3e %16.7f %16.7f %16.7f \n", ctime,niter, fy , cg[1], y3, vy3); fclose(outNB); if(NULL == (outRK = fopen("dataRK3.txt","a"))) { Error("Could not open file for append!\n"); } fprintf(outRK,"%16.4e %12.1f %16.3e %16.7f %16.7f %16.7f \n", ctime,niter, fy , cg[1], y3RK, vy3RK); fclose(outRK); #endif } /*Transfer result to the dynamic mesh*/ vel[0] = 0.0; vel[1] = vy3RK; } DEFINE_CG_MOTION(cylinder_3_frontgrid_1,dt,vel,omega,time,dtime) { NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); vel[0]=0.0; vel[1]=vy3RK; } DEFINE_CG_MOTION(cylinder_3_overset_2,dt,vel,omega,time,dtime) { NV_S(vel, =, 0.0); NV_S(omega, =, 0.0); vel[0]=0.0; vel[1]=vy3RK; } DEFINE_ZONE_MOTION(cylinder_3_zone,omega,axis,origin,velocity,time,dtime) { N3V_D(velocity, =, 0, 0, 0); N3V_S(origin, =, 0.32); N3V_D(axis, =, 0.0, 0.0, 1.0); velocity[1]=vy3RK; }

运动速度.png
运动速度

运动位移.png
运动位移

压力系数.png
压力系数

动网格设置.png
动网格设置

请问解决了吗？也遇到了同样的问题。

各位大佬好，模型是一个0.125x0.5x0.6m的光滑通道，上下壁面均为无滑移的300K恒温壁面，进口温度320K，进出口及左右壁面均采用周期性边界条件，模拟步骤是先用RANS模拟，之后使用TUI指令添加扰动然后切换到LES模拟。按理说流体温度应该小于等于320K而且随时间逐渐减小，但是云图画出来最高温度有323K，又模拟了0.5s后最高温度没什么变化其他地方的温度似乎也没什么变化。周期性设置如图（压力梯度最开始为0）搜狗截图20230903172308.png
我想知道是为啥 :136:

我采用的稳态MRF模型进行模拟，如果桨距角改变，同一来流速度下给旋转域设置的旋转速度需要改变吗

81a56a41-f2c6-4e5c-8504-2cb7df0a1f28-image.png ，我看帮助文档中DPM对droplet的描述是换热、蒸发和沸腾，这都是液滴材料从液相传质到气相，请问能不能实现从气相到液相的传质（就是吸收）？

81a56a41-f2c6-4e5c-8504-2cb7df0a1f28-image.png ，我看帮助文档中DPM对droplet的描述是换热、蒸发和沸腾，这都是液滴材料从液相传质到气相，请问能不能实现从气相到液相的传质（就是吸收）？

@李东岳 这点我清楚，实际上这么多参数里也就总摩擦系数对不上，其他的基本上全对上了。LES的话得在文献里是说在入口用vortex method施加扰动，而且模拟的是有肋的，所以基本上不担心涡的问题。流向周期性的模型也可以在RANS模拟之后用TUI命令施加扰动，之前试过了涡能长期存在，不过那个case没算完结果对不对就不清楚了。

@羽之下 谢谢

请问一下各位大佬，在使用dpm模拟液滴闪蒸时，液滴沸点设置为373k，液滴温度设置为400k，连续相温度为300k，连续相介质为空气，采用双向耦合进行计算，当液滴颗粒射入连续相中时，连续相喷嘴处的温度就迅速上升，可达上千度，甚至报温度超限的错误，请问一下这是为什么呀![QQ图片20230818084454.jpg