帮我用compute force and moment编一个udf
时间: 2024-03-07 09:49:19 浏览: 59
好的,下面是一个简单的 UDF(用户自定义函数),可以用于计算特定区域的力和矩:
```
#include "udf.h"
DEFINE_ON_DEMAND(compute_force_moment)
{
real force[ND_ND], moment[ND_ND];
real origin[ND_ND] = {0.0, 0.0, 0.0};
real area = 0.0;
real centroid[ND_ND] = {0.0, 0.0, 0.0};
real density = 1000.0; // fluid density in kg/m^3
Thread *t = Lookup_Thread(domain, 20); // 20 is the ID of the thread containing the surface zone
face_t f;
begin_f_loop(f, t)
{
F_AREA(area, f, t);
F_CENTROID(centroid, f, t);
F_UDMI(f, t, 0) = area; // store the area of each face as a user-defined memory in Fluent
F_UDMI(f, t, 1) = centroid[0]; // store the x-coordinate of the centroid of each face as a user-defined memory in Fluent
F_UDMI(f, t, 2) = centroid[1]; // store the y-coordinate of the centroid of each face as a user-defined memory in Fluent
F_UDMI(f, t, 3) = centroid[2]; // store the z-coordinate of the centroid of each face as a user-defined memory in Fluent
F_AREA_UNTITLED(force, f, t);
F_MOMENT_UNTITLED(moment, origin, f, t);
C_CENTROID(centroid, t);
C_UDMI(t, 0) += density * area; // store the mass of the fluid in the zone as a user-defined memory in Fluent
C_UDMI(t, 1) += force[0]; // store the x-component of the force acting on the zone as a user-defined memory in Fluent
C_UDMI(t, 2) += force[1]; // store the y-component of the force acting on the zone as a user-defined memory in Fluent
C_UDMI(t, 3) += force[2]; // store the z-component of the force acting on the zone as a user-defined memory in Fluent
C_UDMI(t, 4) += moment[0]; // store the x-component of the moment acting on the zone as a user-defined memory in Fluent
C_UDMI(t, 5) += moment[1]; // store the y-component of the moment acting on the zone as a user-defined memory in Fluent
C_UDMI(t, 6) += moment[2]; // store the z-component of the moment acting on the zone as a user-defined memory in Fluent
}
end_f_loop(f, t);
Message("Forces and moments computed.\n");
}
```
这个 UDF 可以计算指定的表面区域(20 号线程)上的力和矩,并将结果存储在 Fluent 中的用户定义内存中。在模拟过程中,您需要使用 Fluent 的“Execute Commands”功能来调用此 UDF。在 Fluent 中,输入以下命令即可:
```
/define/user-defined/execute-on-demand compute_force_moment
```
需要注意的是,这只是一个简单的 UDF,可能需要根据实际情况进行修改和调整。