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UDF for blade displacement

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Old   January 29, 2020, 03:12
Default UDF for blade displacement
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Hi my friends ... I need to write a UDF for a blade displacement ... I should define Phi (as the picture below eq 11) to use it in another formula( as the picture below eq 10), but I can't make a loop over x to define Phi to use it! it is always one number(number 1.695913)!

here is my UDF ...


#include "udf.h"

#define PI 3.141592654

#define ID 3

real xold=0.0;real yold=0.0;

real uold=0.0;real vold=0.0;

real dx=0.0e0;real dy=0.0e0;

real L=0.03;

real Phi;

DEFINE_EXECUTE_AT_END(ForceCalculate)

{

real Fy=0.0e0;

real x[ND_ND];

real yy;

#if !RP_HOST /* SERIAL or NODE */

real NV_VEC(WS);

real area[ND_ND];

real Fpy = 0.0;

real Fvy=0.0;


Domain *d= Get_Domain(1);

Thread *t=Lookup_Thread(d,ID);

face_t f;


begin_f_loop(f,t)

{

F_CENTROID(x,f,t);

yy=x[0];

Phi = 1-sin(((90*PI)/180)*(yy/L));

}

end_f_loop(f,t);



begin_f_loop(f, t)

if (PRINCIPAL_FACE_P(f,t))

{

F_AREA(area,f,t);

Fpy+=L*area[1]*F_P(f,t)*Phi;

}

end_f_loop(f, t)

Fy = Fpy;


#if RP_NODE /* Perform node synchronized actions here*/

Fy=PRF_GRSUM1(Fy);

Fx=PRF_GRSUM1(Fx);

#endif /* RP_NODE */

#endif /* !RP_HOST */



// Message0(" k=%g wd= %g Fy=%g\n",k,wd,Fy);

// Message0(" time=%g xold= %g deltaT=%g\n",time,xold,ts);



node_to_host_real_2(Fy,Fx); /* Does nothing in SERIAL */



#if !RP_NODE /* SERIAL or HOST */

real C=3.69e-6;

real teta=1.38e-9;

real my=7.789e0;

real kyy=3.6;

real ky=kyy+((teta*teta)/C);

real zety=0.0;

//-----------------------------------

real wny=sqrt(ky/my);

real cy=2.0e0*my*wny*zety;

real wdy=wny*sqrt(1.0e0-zety*zety);

//-----------------------------------

real ts=CURRENT_TIMESTEP;

real time=CURRENT_TIME;

//-----------------------------------

real Ay,By,y;

Ay=yold-Fy/ky;

By=(vold+zety*wny*Ay)/wdy;

y=exp(-zety*wny*ts)*(Ay*cos(wdy*ts)+By*sin(wdy*ts))+Fy/ky;

vold=-zety*wny*(y-Fy/ky)+wdy*exp(-zety*wny*ts)*(By*cos(wdy*ts)-Ay*sin(wdy*ts));

dy=y-yold;

yold=y;

//-----------------------------------



//-----------------------------------

FILE *fout;

fout = fopen ("data2D.out","a");

fprintf(fout," %f %f %f %f %f\n",time,yold,Fy,vold,Phi);

fclose(fout);

#endif /* !RP_NODE */

}


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Old   January 29, 2020, 08:01
Default Phi is a scalar
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It gives only one value for Phi because Phi is declared as a scalar, i.e., it can store only one number. What you need is a vector that can store as many values of Phi as many x are there. Recommended to use UDM in place of Phi.
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Old   January 29, 2020, 08:07
Default how can I do?
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Quote:
Originally Posted by vinerm View Post
It gives only one value for Phi because Phi is declared as a scalar, i.e., it can store only one number. What you need is a vector that can store as many values of Phi as many x are there. Recommended to use UDM in place of Phi.
Thanks for your accountability, since I am poor at writing a UDF and my information is not high, can you correct this for me?
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Old   January 29, 2020, 08:10
Default Suggestions
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You should replace Phi with F_UDMI(f, t, 0) everywhere in the code. Along with that you also need to ensure that you enable one UDM in Fluent and initialize by patching it to 0. UDMs are available at UDFs > Memory.
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Old   January 29, 2020, 08:45
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Quote:
Originally Posted by vinerm View Post
You should replace Phi with F_UDMI(f, t, 0) everywhere in the code. Along with that you also need to ensure that you enable one UDM in Fluent and initialize by patching it to 0. UDMs are available at UDFs > Memory.
again really Thank you ... to be sure that everything is ok, I want to see the Phi data in **fprintf(fout," %f %f %f %f %f\n",time,yold,Fy,vold,Phi);** as I replace the Phi with F_UDMI(f, t, 0), how can I do it?
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Old   January 29, 2020, 08:49
Default Write inside the loop
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Since Phi is not a single value, you have write your output file within the face loop. And as usual, replace Phi with UDM.
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Old   January 29, 2020, 09:07
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Quote:
Originally Posted by vinerm View Post
Since Phi is not a single value, you have write your output file within the face loop. And as usual, replace Phi with UDM.
my apologies ...
I know I am a bad student!!!
here is my improved UDF: Is it ok?!!!!

#include "udf.h"


#define PI 3.141592654
#define ID 3
real xold=0.0;real yold=0.0;
real uold=0.0;real vold=0.0;
real dx=0.0e0;real dy=0.0e0;
real L=0.03;

DEFINE_EXECUTE_AT_END(ForceCalculate)
{
real Fy=0.0e0;
real x[ND_ND];
real yy;

#if !RP_HOST /* SERIAL or NODE */

real NV_VEC(WS);
real area[ND_ND];
real Fpy = 0.0;
real Fvy=0.0;

Domain *d= Get_Domain(1);
Thread *t=Lookup_Thread(d,ID);
face_t f;

begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
yy=x[0];
F_UDMI(f, t, 0) = 1-sin(((90*PI)/180)*(yy/L));
}
end_f_loop(f,t);


begin_f_loop(f, t)
if (PRINCIPAL_FACE_P(f,t))
{
F_AREA(area,f,t);
Fpy+=L*area[1]*F_P(f,t)*F_UDMI(f, t, 0);
}
end_f_loop(f, t)
Fy = Fpy;

#if RP_NODE /* Perform node synchronized actions here*/
Fy=PRF_GRSUM1(Fy);
Fx=PRF_GRSUM1(Fx);
#endif /* RP_NODE */
#endif /* !RP_HOST */

// Message0(" k=%g wd= %g Fy=%g\n",k,wd,Fy);
// Message0(" time=%g xold= %g deltaT=%g\n",time,xold,ts);

node_to_host_real_2(Fy,Fx); /* Does nothing in SERIAL */

#if !RP_NODE /* SERIAL or HOST */
real C=3.69e-6;
real teta=1.38e-9;
real my=7.789e0;
real kyy=3.6;
real ky=kyy+((teta*teta)/C);
real zety=0.0;
//-----------------------------------
real wny=sqrt(ky/my);
real cy=2.0e0*my*wny*zety;
real wdy=wny*sqrt(1.0e0-zety*zety);
//-----------------------------------
real ts=CURRENT_TIMESTEP;
real time=CURRENT_TIME;
//-----------------------------------
real Ay,By,y;
Ay=yold-Fy/ky;
By=(vold+zety*wny*Ay)/wdy;
y=exp(-zety*wny*ts)*(Ay*cos(wdy*ts)+By*sin(wdy*ts))+Fy/ky;
vold=-zety*wny*(y-Fy/ky)+wdy*exp(-zety*wny*ts)*(By*cos(wdy*ts)-Ay*sin(wdy*ts));
dy=y-yold;
yold=y;
//-----------------------------------

//-----------------------------------
FILE *fout;
fout = fopen ("data2D.out","a");
fprintf(fout," %f %f %f %f %f\n",time,yold,Fy,vold,F_UDMI(f, t, 0));
fclose(fout);
#endif /* !RP_NODE */

}
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Old   January 30, 2020, 03:08
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compile code
Code:
#include "udf.h"


#define PI 3.141592654
#define ID 3
real xold=0.0;real yold=0.0;
real uold=0.0;real vold=0.0;
real dx=0.0e0;real dy=0.0e0;
real L=0.03;

DEFINE_EXECUTE_AT_END(ForceCalculate)
{
real Fy=0.0e0;
real x[ND_ND];
real yy;
real C=3.69e-6;
real teta=1.38e-9;
real my=7.789e0;
real kyy=3.6;
real ky=kyy+((teta*teta)/C);
real zety=0.0;
//-----------------------------------
real wny=sqrt(ky/my);
real cy=2.0e0*my*wny*zety;
real wdy=wny*sqrt(1.0e0-zety*zety);
//-----------------------------------
real ts=CURRENT_TIMESTEP;
real time=CURRENT_TIME;
//-----------------------------------
real Ay,By,y;
FILE *fout;



real NV_VEC(WS);
real area[ND_ND];
real Fpy = 0.0;
real Fvy=0.0;

Domain *d= Get_Domain(1);
Thread *t=Lookup_Thread(d,ID);
face_t f;

begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
yy=x[0];
F_UDMI(f, t, 0) = 1-sin(((90*PI)/180)*(yy/L));
}
end_f_loop(f,t);


begin_f_loop(f, t)
if (PRINCIPAL_FACE_P(f,t))
{
F_AREA(area,f,t);
Fpy+=L*area[1]*F_P(f,t)*F_UDMI(f, t, 0);
}
end_f_loop(f, t)
Fy = Fpy;
#if RP_NODE /* SERIAL or NODE */
Fy=PRF_GRSUM1(Fy);
#endif /* RP_NODE */

// Message0(" k=%g wd= %g Fy=%g\n",k,wd,Fy);
// Message0(" time=%g xold= %g deltaT=%g\n",time,xold,ts);

node_to_host_real_1(Fy); /* Does nothing in SERIAL */

#if !RP_NODE /* SERIAL or HOST */

Ay=yold-Fy/ky;
By=(vold+zety*wny*Ay)/wdy;
y=exp(-zety*wny*ts)*(Ay*cos(wdy*ts)+By*sin(wdy*ts))+Fy/ky;
vold=-zety*wny*(y-Fy/ky)+wdy*exp(-zety*wny*ts)*(By*cos(wdy*ts)-Ay*sin(wdy*ts));
dy=y-yold;
yold=y;
//-----------------------------------

//-----------------------------------

fout = fopen ("data2D.out","a");
fprintf(fout," %f %f %f %f %f\n",time,yold,Fy,vold,F_UDMI(f, t, 0));
fclose(fout);
#endif /* !RP_NODE */
}
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Old   January 30, 2020, 04:45
Default Segmentation Violation Expected
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The code that Alexander shared will work for most of the part; I haven't checked it line by line but most likely it will do most of the work, except for writing. You should get Segmentation Violation while writing the output since f does not exist outside begin_f_loop. Therefore, any command making use of f has to be within the loop.
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Old   January 30, 2020, 05:14
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Quote:
Originally Posted by AlexanderZ View Post
compile code
Code:
#include "udf.h"


#define PI 3.141592654
#define ID 3
real xold=0.0;real yold=0.0;
real uold=0.0;real vold=0.0;
real dx=0.0e0;real dy=0.0e0;
real L=0.03;

DEFINE_EXECUTE_AT_END(ForceCalculate)
{
real Fy=0.0e0;
real x[ND_ND];
real yy;
real C=3.69e-6;
real teta=1.38e-9;
real my=7.789e0;
real kyy=3.6;
real ky=kyy+((teta*teta)/C);
real zety=0.0;
//-----------------------------------
real wny=sqrt(ky/my);
real cy=2.0e0*my*wny*zety;
real wdy=wny*sqrt(1.0e0-zety*zety);
//-----------------------------------
real ts=CURRENT_TIMESTEP;
real time=CURRENT_TIME;
//-----------------------------------
real Ay,By,y;
FILE *fout;



real NV_VEC(WS);
real area[ND_ND];
real Fpy = 0.0;
real Fvy=0.0;

Domain *d= Get_Domain(1);
Thread *t=Lookup_Thread(d,ID);
face_t f;

begin_f_loop(f,t)
{
F_CENTROID(x,f,t);
yy=x[0];
F_UDMI(f, t, 0) = 1-sin(((90*PI)/180)*(yy/L));
}
end_f_loop(f,t);


begin_f_loop(f, t)
if (PRINCIPAL_FACE_P(f,t))
{
F_AREA(area,f,t);
Fpy+=L*area[1]*F_P(f,t)*F_UDMI(f, t, 0);
}
end_f_loop(f, t)
Fy = Fpy;
#if RP_NODE /* SERIAL or NODE */
Fy=PRF_GRSUM1(Fy);
#endif /* RP_NODE */

// Message0(" k=%g wd= %g Fy=%g\n",k,wd,Fy);
// Message0(" time=%g xold= %g deltaT=%g\n",time,xold,ts);

node_to_host_real_1(Fy); /* Does nothing in SERIAL */

#if !RP_NODE /* SERIAL or HOST */

Ay=yold-Fy/ky;
By=(vold+zety*wny*Ay)/wdy;
y=exp(-zety*wny*ts)*(Ay*cos(wdy*ts)+By*sin(wdy*ts))+Fy/ky;
vold=-zety*wny*(y-Fy/ky)+wdy*exp(-zety*wny*ts)*(By*cos(wdy*ts)-Ay*sin(wdy*ts));
dy=y-yold;
yold=y;
//-----------------------------------

//-----------------------------------

fout = fopen ("data2D.out","a");
fprintf(fout," %f %f %f %f %f\n",time,yold,Fy,vold,F_UDMI(f, t, 0));
fclose(fout);
#endif /* !RP_NODE */
}
Thank you ... a problem acquired! for *F_UDMI(f, t, 0)* this write 0!
in the links I send you my Mesh, My output Data and my article I am working on! my last Target is to simulate the blade displacement!
http://s7.picofile.com/file/83865613..._yeki.msh.html
http://s6.picofile.com/file/8386561326/data2D.out.html
http://s7.picofile.com/file/83865613...rials.pdf.html
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Old   January 30, 2020, 05:21
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yeah! this writes the F_UDMI(f, t, 0) by zero, I am really Tired by this! can I have Conversation with you in private! I will send you my article I am working on it! maybe you can help me... this is more than 3 month I am working on this UDF
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Old   January 30, 2020, 06:42
Default Not working part
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Which part of the UDF is not working. About writing I know it will not work but the solution is simple; just do writing within the loop, i.e., move the line with command fprintf before the end_f_loop. Is there any other issue with it?
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Old   January 30, 2020, 08:53
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Quote:
Originally Posted by vinerm View Post
Which part of the UDF is not working. About writing I know it will not work but the solution is simple; just do writing within the loop, i.e., move the line with command fprintf before the end_f_loop. Is there any other issue with it?
thank you my friend, the problem loop over x solved!
how can I make a grid motion to simulating the blade displacement?!
with use of the function in the picture:
yt is yold in my code and Phi is F_UDMI(f, t, 0)

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Old   January 30, 2020, 09:49
Default Define_grid_motion
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Look for DEFINE_GRID_MOTION example in UDF manual
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Old   January 30, 2020, 12:36
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Quote:
Originally Posted by vinerm View Post
Look for DEFINE_GRID_MOTION example in UDF manual
thanks ... there is just one question, how can I use *yold* in the *DEFINE_EXECUTE_AT_END* macro to use it in *Grid motion* macro?
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Old   January 31, 2020, 04:18
Default Use UDM
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For all those variables that are varying with space, i.e., functions of their position, it is recommended to use UDM. It appears that yold is also a function of position. Therefore, you should invoke another UDM, and use F_UDMI(f,t,1) to store the value and then use same UDM in GRID_MOTION
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