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3D wing (flapping elastically) flexing UDF problem |
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#1 |
New Member
Join Date: Feb 2012
Posts: 4
Rep Power: 14 ![]() |
Hello, Im trying to simulate the flexing( flapping up and down elastically) of a wing in 3D. But im having problems with the UDF, its just rotating the wing along the x direction instead of updating the y position based on the position of the z position to flap it down. I'd be very happy if somebody could help me with it. Im attaching a picture showing only the wing to help with axis. The UDF im using is as follows:
#include"udf.h" DEFINE_GRID_MOTION(wing, domain, dt, time, dtime) { Thread *tf = DT_THREAD (dt); face_t f; Node *v; real NV_VEC (axis), dy; real NV_VEC (origin); int n; /* set deforming flag on adjacent cell zone */ SET_DEFORMING_THREAD_FLAG (THREAD_T0 (tf)); Message ("time = %f\n", time); NV_D (axis, =, 0.0, 0.0, 1.0); NV_D (origin, =, 0.0, 0.0, 0.0); begin_f_loop (f, tf) { f_node_loop (f, tf, n) { v = F_NODE (f, tf, n); /* update node if z position is greater than 0.000 and that the current node has not been previously visited when looping through previous faces */ if (NODE_Z (v) > 0.000 && 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); dy = (0.0271*pow (NODE_Z (v), 2)) + (0.2496*NODE_Z (v)) + 0.1396; NODE_Y (v) = NODE_Y (v) + dy; } } } end_f_loop (f, tf); } |
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#2 |
Senior Member
kunar
Join Date: Nov 2011
Posts: 117
Rep Power: 14 ![]() |
Dear djan,
i am also trying to do analysis in flapping wing(dragonfly),i draw cad model in catia,and i did mesh in gambit right now i am trying to write udf and compile in fluent ,i dont know how to write, i saw your post i want some help from you i am starting stage only for write udf.kindly guide me |
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#3 |
Member
Join Date: Mar 2011
Posts: 50
Rep Power: 15 ![]() |
either something wrong with your equation
or the way you update ur nodes I think it has something to do with updating the nodes |
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#4 |
New Member
irfan khan
Join Date: Aug 2011
Posts: 11
Rep Power: 15 ![]() |
function probably seem to be parabolic. for flapping, sinsusoidal is required. moreover time varation be also included.
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Tags |
3d fluent, dynamic mesh, udf, wing flapping |
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