[Saman95]

hello dear

Does anyone have tutorial about dynamic mesh grid motion?

[Saman95]

this is a example from Ansys fluent udf manual but I don;t understand some of commands like:

1- SET_DEFORMING_THREAD_FLAG(THREAD_T0(tf));

2- NODE_POS_UPDATED(v);

3- NV_V(NODE_COORD(v), +=, dx);

4- real NV_VEC(omega), NV_VEC(axis), NV_VEC(dx);real NV_VEC(origin), NV_VEC(rvec);


can u explain me?




#include "udf.h"
DEFINE_GRID_MOTION(beam,domain,dt,time,dtime)
{
Thread *tf = DT_THREAD(dt);
face_t f;
Node *v;
real NV_VEC(omega), NV_VEC(axis), NV_VEC(dx);
real NV_VEC(origin), NV_VEC(rvec);
real sign;
int n;
/* set deforming flag on adjacent cell zone */
SET_DEFORMING_THREAD_FLAG(THREAD_T0(tf));
sign = -5.0 * sin (26.178 * time);
Message ("time = %f, omega = %f\n", time, sign);
NV_S(omega, =, 0.0);
NV_D(axis, =, 0.0, 1.0, 0.0);
NV_D(origin, =, 0.0, 0.0, 0.152);
begin_f_loop(f,tf)
{
f_node_loop(f,tf,n)
{
v = F_NODE(f,tf,n);
/* update node if x position is greater than 0.02
and that the current node has not been previously
visited when looping through previous faces */
if (NODE_X(v) > 0.020 && NODE_POS_NEED_UPDATE (v))
{
/* indicate that node position has been update
so that it’s not updated more than once */
NODE_POS_UPDATED(v);
omega[1] = sign * pow (NODE_X(v)/0.230, 0.5);
NV_VV(rvec, =, NODE_COORD(v), -, origin);
NV_CROSS(dx, omega, rvec);
NV_S(dx, *=, dtime);
NV_V(NODE_COORD(v), +=, dx);
187
Release 14.5 - © SAS IP, Inc. All rights reserved. - Contains proprietary and confidential information
of ANSYS, Inc. and its subsidiaries and affiliates.
Dynamic Mesh DEFINEMacros
}
}
}
end_f_loop(f,tf);
}