{"id":166519,"date":"2022-02-17T21:14:37","date_gmt":"2022-02-17T21:14:37","guid":{"rendered":"\/forum\/forums\/topic\/x-momentum-source-using-fluent-udfs\/"},"modified":"2022-02-18T15:58:08","modified_gmt":"2022-02-18T15:58:08","slug":"x-momentum-source-using-fluent-udfs","status":"closed","type":"topic","link":"https:\/\/innovationspace.ansys.com\/forum\/forums\/topic\/x-momentum-source-using-fluent-udfs\/","title":{"rendered":"X-momentum source using Fluent UDFs"},"content":{"rendered":"
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Dear colleagues,<\/p>\n

I am trying to implement an x-momentum source term on a background grid using Fluent UDFs. See my source term below:<\/p>\n

<\/p>\n<\/p>\n

DEFINE_SOURCE(ALM,c,t,dS,eqn)<\/p>\n

{<\/p>\n

real xc[ND_ND];<\/p>\n

real con, source;<\/p>\n

C_CENTROID(xc,c,t);<\/p>\n

source = C_UDSI(c,t,0);<\/p>\n

dS[eqn] = 0;<\/p>\n

<\/p>\n<\/p>\n

return source;<\/p>\n

}<\/p>\n

<\/p>\n<\/p>\n

Where C_UDSI(c,t,0) is a user defined scalar that is determined using an adjust macro. The value of C_UDSI(c,t,0) is a Gaussian distribution acting for a given region of cells and its implementation is presumably correct.<\/p>\n

<\/p>\n<\/p>\n

I am encountering issues with the source term implementation. Specifically, there is no change to the flow field when activating the source term. It is as if the source term is being neglected entirely; it introduces no change to the velocity of the flow in the defined region where UDS-0 acts. Any help would be appreciated. Thank you.<\/p>\n","protected":false},"template":"","class_list":["post-166519","topic","type-topic","status-closed","hentry","topic-tag-momentum-source-1","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