{"id":163317,"date":"2021-10-23T08:57:34","date_gmt":"2021-10-23T08:57:34","guid":{"rendered":"\/forum\/forums\/topic\/dpm-drag-force-store-in-udmi\/"},"modified":"2021-10-25T11:21:44","modified_gmt":"2021-10-25T11:21:44","slug":"dpm-drag-force-store-in-udmi","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/dpm-drag-force-store-in-udmi\/","title":{"rendered":"DPM drag force store in UDMI"},"content":{"rendered":"
\n
\n

Dear All, <\/p>\n

I'm working on air-water two fluid system using DPM method. The darg force is implinted via UDF. I want to store the DPM drag force magnitude in a UDMI. What modification it required to store 'drag_force' in an UDMI? <\/p>\n

Drag UDF as follow:<\/p>\n

# include "udf.h"<\/p>\n

# include "dpm.h"<\/p>\n

DEFINE_DPM_DRAG(particle_drag_force,Re,p)<\/p>\n

{<\/p>\n

Thread *t= P_CELL_THREAD(p); \/*not sure about this line*\/<\/p>\n

cell_t c= P_CELL(p); \/*not sure about this line*\/<\/p>\n

real dia, etov;<\/p>\n

real adrag, bdrag, cdrag, drag_force;<\/p>\n

dia=0.005;  \/* bubble diameter *\/<\/p>\n

\/* to compute Eotvos Number *\/<\/p>\n

etov=9.81*994.38*(dia*dia)\/0.072;<\/p>\n

\/* to compute the drag coefficient *\/<\/p>\n

adrag=24.0*(1+0.15*pow(Re,0.687))\/Re;<\/p>\n

bdrag=8.0*etov\/(3.0*etov+12.0);<\/p>\n

if(adrag>bdrag)<\/p>\n

{cdrag=adrag;}<\/p>\n

else <\/p>\n

{cdrag=bdrag;}<\/p>\n

drag_force=(18.0*cdrag*Re)\/24.0; \/*this term I want to store in a UDMI*\/<\/p>\n

C_UDMI(c,t,0)=cdrag;<\/p>\n

C_UDMI(c,t,1)=drag_force;<\/p>\n

return (drag_force);<\/p>\n

}<\/p>\n

UDMI requires to access cell and thread, how do I define in DPM simulation?<\/p>\n","protected":false},"template":"","class_list":["post-163317","topic","type-topic","status-closed","hentry","topic-tag-dpm-udfs","topic-tag-udf-fluent"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t