TAGGED: ansys-fluent, dpm-model, dpm-udfs, udf-compilation
June 27, 2022 at 3:02 pmkamatsaSubscriber
Hello. I am trying to introduce a force in the DPM_BODY_FORCE macro in the DPM model. The force is dependent on the flow velocity so I want to incorporate the flow velocity into the equation. My code is:
if (TP_POS(tp) >= 0.05)
if(i == 1)
Fd = -1* (pi * km * epsilon * D * D * L / 6) / (alpha / (alpha - 1) - f) * pow(V / log(R2 / R1), 2) * pow(1 / TP_POS(tp), 3)+pi*mu*D*4* fabs(TP_VEL(tp))*(pow(beta,2)-1)/((2*pow(beta,2)-1)*(log(beta+sqrt(pow(beta,2)-1))/sqrt(pow(beta,2)-1)-beta));
else if (i == 0)
Fd = -1*pi * mu * D * fabs(C_U(c,t)-TP_VEL(tp)) * 8 * (pow(beta, 2) - 1) / ((2 * pow(beta, 2) - 3) * (log(beta + sqrt(pow(beta, 2) - 1)) / sqrt(pow(beta, 2) - 1) + beta));
I am getting the following error during compilation:
error: use of undeclared identifier 'c'
error: use of undeclared identifier 't'
Is this because I am using the flow variables in a different macro that does not have the variables t & c in its declaration. If yes, how do I fix this.
Some help would be appreciated.
June 28, 2022 at 10:44 amRobAnsys Employee
Have a look at the example here https://ansyshelp.ansys.com/account/Secured?returnurl=/Views/Secured/corp/v221/en/flu_udf/flu_udf_sec_define_dpm_body_force.html
June 28, 2022 at 11:50 amDrAmineAnsys Employee
Check the manual for more examples.
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